@article{meyer_price_ercumen_2024, title={Do animal husbandry operations contaminate groundwater sources with antimicrobial resistance: systematic review}, volume={2}, ISSN={["1614-7499"]}, DOI={10.1007/s11356-024-31899-w}, abstractNote={Abstract}, journal={ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH}, author={Meyer, Cameron and Price, Skyler and Ercumen, Ayse}, year={2024}, month={Feb} }
 @article{contreras_islam_mertens_pickering_arnold_benjamin-chung_hubbard_rahman_unicomb_luby_et al._2024, title={Improved Child Feces Management Mediates Reductions in Childhood Diarrhea from an On-Site Sanitation Intervention: Causal Mediation Analysis of a Cluster-Randomized Trial in Rural Bangladesh}, volume={3}, ISSN={["2210-6014"]}, DOI={10.1007/s44197-024-00210-y}, abstractNote={Abstract}, journal={JOURNAL OF EPIDEMIOLOGY AND GLOBAL HEALTH}, author={Contreras, Jesse D. and Islam, Mahfuza and Mertens, Andrew and Pickering, Amy J. and Arnold, Benjamin F. and Benjamin-Chung, Jade and Hubbard, Alan E. and Rahman, Mahbubur and Unicomb, Leanne and Luby, Stephen P. and et al.}, year={2024}, month={Mar} }
 @article{islam_rahman_kafi_unicomb_rahman_mertens_benjamin-chung_arnold_colford_luby_et al._2023, title={Assessing sustained uptake of latrine and child feces management interventions: Extended follow-up of a cluster-randomized controlled trial in rural Bangladesh 1-3.5 years after intervention initiation}, volume={250}, ISSN={["1618-131X"]}, DOI={10.1016/j.ijheh.2023.114149}, abstractNote={Sanitation interventions typically result in modest increases in latrine access, and any gains in latrine access and use are often not sustained over time. Sanitation programs also rarely include child-focused interventions such as potties. We aimed to assess the sustained effect of a multi-component sanitation intervention on access to and use of latrines and child feces management tools in rural Bangladesh.We conducted a longitudinal substudy nested within the WASH Benefits randomized controlled trial. The trial provided latrine upgrades, child potties and sani-scoops for feces removal, along with behavior change promotion to encourage use of the delivered hardware. Promotion visits to intervention recipients were frequent during the first 2 years after intervention initiation, decreased in frequency between years 2-3, and ceased after 3 years. We enrolled a random subset of 720 households from the sanitation and control arms of the trial in a substudy and visited them quarterly between 1 and 3.5 years after intervention initiation. At each visit, field staff recorded sanitation-related behaviors through spot-check observations and structured questionnaires. We assessed intervention effects on observed indicators of hygienic latrine access, potty use and sani-scoop use and investigated whether these effects were modified by duration of follow-up, ongoing behavior change promotion and household characteristics.The intervention increased hygienic latrine access from 37% among controls to 94% in the sanitation arm (p < 0.001). Access among intervention recipients remained high 3.5 years after intervention initiation, including periods with no active promotion. Gains in access were higher among households with less education, less wealth and larger number of residents. The intervention increased availability of child potties from 29% among controls to 98% in the sanitation arm (p < 0.001). However, fewer than 25% of intervention households reported exclusive child defecation in a potty or had observed indicators of potty and sani-scoop use, and gains in potty use declined over the follow-up period, even with ongoing promotion.Our findings from an intervention that provided free products and intensive initial behavior change promotion suggest a sustained increase in hygienic latrine access up to 3.5 years after intervention initiation but infrequent use of child feces management tools. Studies should investigate strategies to ensure sustained adoption of safe child feces management practices.}, journal={INTERNATIONAL JOURNAL OF HYGIENE AND ENVIRONMENTAL HEALTH}, author={Islam, Mahfuza and Rahman, Mahbubur and Kafi, Mohammad Abdullah Heel and Unicomb, Leanne and Rahman, Mostafizur and Mertens, Andrew and Benjamin-Chung, Jade and Arnold, Benjamin F. and Colford, John M., Jr. and Luby, Stephen P. and et al.}, year={2023}, month={May} }
 @article{rahman_alam_luies_kamal_ferdous_lin_sharior_khan_rahman_parvez_et al._2022, title={Contamination of Fresh Produce with Antibiotic-Resistant Bacteria and Associated Risks to Human Health: A Scoping Review}, DOI={10.3390/ijerph19010360}, abstractNote={Fresh produce, when consumed raw, can be a source of exposure to antimicrobial residues, antimicrobial-resistant bacteria (ARB) and antimicrobial resistance genes (ARGs) of clinical importance. This review aims to determine: (1) the presence and abundance of antimicrobial residues, ARB and ARGs in fresh agricultural products sold in retail markets and consumed raw; (2) associated health risks in humans; and (3) pathways through which fresh produce becomes contaminated with ARB/ARGs. We searched the Ovid Medline, Web of Science and Hinari databases as well as grey literature, and identified 40 articles for inclusion. All studies investigated the occurrence of multidrug-resistant bacteria, and ten studies focused on ARGs in fresh produce, while none investigated antimicrobial residues. The most commonly observed ARB were E. coli (42.5%) followed by Klebsiella spp. (22.5%), and Salmonella spp. (20%), mainly detected on lettuce. Twenty-five articles mentioned health risks from consuming fresh produce but none quantified the risk. About half of the articles stated produce contamination occurred during pre- and post-harvest processes. Our review indicates that good agricultural and manufacturing practices, behavioural change communication and awareness-raising programs are required for all stakeholders along the food production and consumption supply chain to prevent ARB/ARG exposure through produce.}, journal={INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH}, author={Rahman, Mahbubur and Alam, Mahbub-Ul and Luies, Sharmin Khan and Kamal, Abul and Ferdous, Sharika and Lin, Audrie and Sharior, Fazle and Khan, Rizwana and Rahman, Ziaur and Parvez, Sarker Masud and et al.}, year={2022}, month={Jan} }
 @article{contreras_islam_mertens_pickering_arnold_benjamin-chung_hubbard_rahman_unicomb_luby_et al._2022, title={Evaluation of an on-site sanitation intervention against childhood diarrhea and acute respiratory infection 1 to 3.5 years after implementation: Extended follow-up of a cluster-randomized controlled trial in rural Bangladesh}, volume={19}, ISSN={["1549-1676"]}, url={http://dx.doi.org/10.1371/journal.pmed.1004041}, DOI={10.1371/journal.pmed.1004041}, abstractNote={
Background
Diarrhea and acute respiratory infection (ARI) are leading causes of death in children. The WASH Benefits Bangladesh trial implemented a multicomponent sanitation intervention that led to a 39% reduction in the prevalence of diarrhea among children and a 25% reduction for ARI, measured 1 to 2 years after intervention implementation. We measured longer-term intervention effects on these outcomes between 1 to 3.5 years after intervention implementation, including periods with differing intensity of behavioral promotion.
}, number={8}, journal={PLOS MEDICINE}, publisher={Public Library of Science (PLoS)}, author={Contreras, Jesse D. and Islam, Mahfuza and Mertens, Andrew and Pickering, Amy J. and Arnold, Benjamin F. and Benjamin-Chung, Jade and Hubbard, Alan E. and Rahman, Mahbubur and Unicomb, Leanne and Luby, Stephen P. and et al.}, editor={Bhutta, Zulfiqar A.Editor}, year={2022}, month={Aug} }
 @article{lowe_ercumen_prottas_harris_2022, title={Exploring the determinants and indicators of poultry feces management behaviors in rural Western Uganda}, volume={834}, ISSN={["1879-1026"]}, url={http://dx.doi.org/10.1016/j.scitotenv.2022.155202}, DOI={10.1016/j.scitotenv.2022.155202}, abstractNote={Animal ownership has reported financial and nutritional benefits but has also been associated with enteric and respiratory infections, and inadequate sanitation and hygiene can lead to children touching and ingesting animal fecal matter. We identified key indicators for poultry feces management and investigated their social determinants using data from a baseline survey of a randomized-controlled trial of a poultry management training program in rural Western Uganda. The baseline survey was conducted in the Masindi and Kiryandongo districts of Uganda in September 2019, and data collected from 609 households were used. We evaluated indicators for poultry feces management behaviors using scale development methods, including descriptive statistics, bivariate correlation analyses, and Factor Analysis of Mixed Data. We also investigated social determinants of key poultry feces management behaviors using logistic and multinomial logistic regression models. A significant increase in odds of having free-roaming poultry was found for each additional poultry owned (OR = 1.18, P < 0.001). The odds of a household having an observed enclosure for poultry increased by 5% with each incremental poultry owned (OR = 1.05, P < 0.001), and by 4% with increasing wealth with each additional point on the poverty probability index score (OR = 1.04, P < 0.001). Our results also suggest enclosures are intermittently used and constructing them without further intervention likely will not be sufficient for effectively managing animal fecal contamination. We recommend that future studies on animal feces management measure indicators for corralling and feces disposal practices and evaluate their relationship to enteric pathogen exposure and health outcomes. Insights from this work can inform the development of robust indicators of poultry feces management behaviors that can be used for monitoring and evaluation purposes.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, publisher={Elsevier BV}, author={Lowe, Jeremy and Ercumen, Ayse and Prottas, Chris and Harris, R. Angela}, year={2022}, month={Aug} }
 @article{rahman_islam_doza_naser_shoab_rosenbaum_islam_unicomb_clasen_ercumen_2022, title={Higher helminth ova counts and incomplete decomposition in sand-enveloped latrine pits in a coastal sub-district of Bangladesh}, volume={16}, url={http://dx.doi.org/10.1371/journal.pntd.0010495}, DOI={10.1371/journal.pntd.0010495}, abstractNote={Pit latrines are the most common latrine technology in rural Bangladesh, and untreated effluent from pits can directly contaminate surrounding aquifers. Sand barriers installed around the latrine pit can help reduce contamination but can also alter the decomposition of the fecal sludge and accelerate pit fill-up, which can counteract their benefits. We aimed to evaluate whether there was a difference in decomposition of fecal sludge and survival of soil-transmitted helminth (STH) ova among latrines where a 50-cm sand barrier was installed surrounding and at the bottom of the pit, compared to latrines without a sand barrier, in coastal Bangladesh. We assessed decomposition in latrine pits by measuring the carbon-nitrogen (C/N) ratio of fecal sludge. We enumerated Ascaris lumbricoides and Trichuris trichiura ova in the pit following 18 and 24 months of latrine use. We compared these outcomes between latrines with and without sand barriers using generalized linear models with robust standard errors to adjust for clustering at the village level. The C/N ratio in latrines with and without a sand barrier was 13.47 vs. 22.64 (mean difference: 9.16, 95% CI: 0.15, 18.18). Pits with sand barriers filled more quickly and were reportedly emptied three times more frequently than pits without; 27/34 latrines with sand barriers vs. 9/34 latrines without barriers were emptied in the previous six months. Most reported disposal methods were unsafe. Compared to latrines without sand barriers, latrines with sand barriers had significantly higher log10 mean counts of non-larvated A. lumbricoides ova (log10 mean difference: 0.35, 95% CI: 0.12, 0.58) and T. trichiura ova (log10 mean difference: 0.47, 95% CI: 0.20, 0.73). Larvated ova counts were similar for the two types of latrines for both A. lumbricoides and T. trichiura. Our findings suggest that sand barriers help contain helminth ova within the pits but pits with barriers fill up more quickly, leading to more frequent emptying of insufficiently decomposed fecal sludge. Further research is required on latrine technologies that can both isolate pathogens from the environment and achieve rapid decomposition.}, number={6}, journal={PLOS Neglected Tropical Diseases}, publisher={Public Library of Science (PLoS)}, author={Rahman, Mahbubur and Islam, Mahfuza and Doza, Solaiman and Naser, Abu Mohammed and Shoab, Abul Kasham and Rosenbaum, Julia and Islam, Md. Shariful and Unicomb, Leanne and Clasen, Thomas F. and Ercumen, Ayse}, editor={Leon, TomasEditor}, year={2022}, month={Jun}, pages={e0010495} }
 @article{contreras_islam_mertens_pickering_kwong_arnold_benjamin-chung_hubbard_alam_sen_et al._2022, title={Influence of community-level sanitation coverage and population density on environmental fecal contamination and child health in a longitudinal cohort in rural Bangladesh}, volume={245}, ISSN={["1618-131X"]}, url={http://dx.doi.org/10.1016/j.ijheh.2022.114031}, DOI={10.1016/j.ijheh.2022.114031}, abstractNote={Household-level sanitation interventions have had limited effects on child health or environmental contamination, potentially due to low community coverage. Higher community-level coverage with safely managed sanitation can reduce opportunities for disease transmission.We estimated associations between community sanitation coverage, environmental fecal contamination, and child health among 360 compounds in the control arm of the WASH Benefits trial in rural Bangladesh (NCT01590095). In each compound, we enumerated E. coli in environmental samples and recorded the 7-day prevalence of caregiver-reported diarrheal disease and acute respiratory infections (ARI) in children under five. We observed indicators of latrine access and quality among all neighboring compounds within 100 m of study compounds. We defined community coverage as the proportion of neighboring compounds with (1) at least one latrine, and (2) exclusively hygienic latrines (improved facility observed to safely contain feces), within both 50 m and 100 m of study compounds. We assessed effect modification by population density and season.Adjusted for confounders, study compounds surrounded by 100% coverage of at least one latrine per compound within 50 m had slightly lower log10E. coli counts in stored water (Δlog = -0.13, 95% CI -0.26, -0.01), child hand rinses (Δlog = -0.13, 95% CI -0.24, -0.02), and caregiver hand rinses (Δlog = -0.16, 95% CI -0.29, -0.03) and marginally lower prevalence of diarrheal disease (prevalence ratio [PR] = 0.82, 95% CI 0.64, 1.04) and ARI (PR = 0.84, 95% CI 0.69, 1.03) compared to compounds surrounded by <100% coverage. Effects were similar but less pronounced at 100 m. At higher population densities, community latrine coverage was associated with larger reductions in E. coli on child and caregiver hands and prevalence of diarrheal disease. Coverage with exclusively hygienic latrines was not associated with any outcome.Higher community sanitation coverage was associated with reduced fecal contamination and improved child health, with stronger effects at highly local scales (50m) and at high population densities. Our findings indicate that the relationship between community sanitation coverage, environmental contamination, and child health varies by definition of coverage, distance, and population density. This work highlights significant uncertainty around how to best measure sanitation coverage and the expected health effects of increasing sanitation coverage using a specific metric. Better understanding of community-level sanitation access is needed to inform policy for implementing sanitation systems that effectively protect community health.}, journal={INTERNATIONAL JOURNAL OF HYGIENE AND ENVIRONMENTAL HEALTH}, publisher={Elsevier BV}, author={Contreras, Jesse D. and Islam, Mahfuza and Mertens, Andrew and Pickering, Amy J. and Kwong, Laura H. and Arnold, Benjamin F. and Benjamin-Chung, Jade and Hubbard, Alan E. and Alam, Mahfuja and Sen, Debashis and et al.}, year={2022}, month={Aug} }
 @article{ercumen_guiteras_spears_2021, title={Biology, behavior and policy, or, Dr. Fauci, Sen. Paul and Prof. Lucas walk into a pandemic}, volume={31}, ISSN={2589-5370}, url={http://dx.doi.org/10.1016/j.eclinm.2020.100719}, DOI={10.1016/j.eclinm.2020.100719}, abstractNote={In a highly-publicized recent exchange in the U.S. Senate, Dr. Anthony Fauci and Sen. Rand Paul expressed radically different views on the level of herd immunity needed to contain the coronavirus epidemic. Sen. Paul noted that transmission rates in New York City appeared low, despite the virus's high inherent infectiousness, proposing that this was evidence that the share of the population already infected was sufficient to have reached herd immunity. Dr. Fauci memorably responded, “If you believe 22% is herd immunity, I believe you're alone in that” [[1]U.S. Senate. Committee on health, education, labor & pensions COVID-19: an update on the federal response. https://www.help.senate.gov/hearings/covid-19-an-update-on-the-federal-response. Accessed online 10 Dec 2020.Google Scholar]. For Sen. Paul, the implication of a low threshold for herd immunity is that restrictions on activity can be reduced without risking runaway disease transmission. If correct, this would be welcome, since such restrictions have immense economic, health and emotional costs. Unfortunately, his policy recommendation suffers from a crucial flaw in logic: it ignores the Lucas critique. Prof. Robert Lucas's Nobel-prize-winning insight, developed in the study of the unemployment-inflation tradeoff in macroeconomics, was that empirical relationships observed under one policy regime cannot necessarily be used to argue for a change in policy [[2]Lucas R.E. Econometric policy evaluation: a critique.Carnegie Rochester Conf Ser Public Policy. 1976; 1: 19-46Crossref Scopus (1933) Google Scholar]. The logic is simple, but profound: the relationships we observe in the data depend on behavior, and behavior responds to and is affected by policy, so when policy changes we should expect behavior to change as well. As a result, we cannot expect the empirical relationships observed under the previous policy regime to continue under the new policy regime, nor can we claim that our new policy will have the effects we would anticipate if behavior were fixed. How does this insight from macroeconomics apply to coronavirus and herd immunity? Suppose we grant Sen. Paul's claim that, in previously hard-hit areas such as New York City, relatively low shares of the population previously infected have contributed in important ways to slowing the spread of disease. Even so, his policy conclusion—that distancing, masking and restrictions on activity can safely end—does not follow. The Lucas Critique reminds us that by changing policy, we change behavior, which in turn will affect the relationships on which we based our policy change. A little math can help. In a standard, simple epidemiological model, the population threshold for herd immunity, commonly denoted p, is given by the formulap=1−(1/R0),where R0 is the basic reproduction number and refers to the expected number of secondary cases that result from one infected case. For an extremely contagious disease like measles, R0 might be about 10, leading to a p of about 0.9, which is why attaining high rates of immunization is so important. For a much less contagious disease, the threshold is lower. For example, if R0 = 1.2, then p = 0.17. Once more than 17% of the population is immune, whether through infection or from vaccination, we expect the disease to die out. The details change in more complex models, for example if different sub-populations spread the disease at different rates, or if acquired immunity is only partial, but the basic insight is the same: the less infectious a disease is, the lower the herd immunity threshold. While this insight is correct, it is easy to make two conceptual mistakes. The first mistake would be to assume that R0 is a fixed, intrinsic biological property of a disease. While some diseases are inherently more contagious than others, R0 is a result of both biology (i.e., duration of being contagious, risk of infection for a given level of exposure) but also of environment and behavior (i.e., contact rate between susceptible and infected individuals, amount of exposure when a contact occurs) [[3]Delamater P.L. Street E.J. Leslie T.F. Yang Y.T. Jacobsen K.H. Complexity of the basic reproduction number (R).Emerg Infect Dis. 2019; 25: 1-4Crossref PubMed Scopus (284) Google Scholar]. This is why we should wear masks, maintain physical distance, meet other people outdoors rather than indoors whenever feasible, and so on: even if we cannot change the inherent infectiousness of the disease, we can still reduce R0. The second mistake would be to forget the Lucas critique: even if we concede that the low share of previously infected people exceeded a herd immunity threshold, it does not follow that we can use this observation to argue for fewer restrictions on activity, or to tell the public that fewer precautions are needed. If indeed the herd immunity threshold was low, it is likely that this was in large part because public policy and private behavior contributed to keeping R0 low. Policies such as shelter-in-place orders have successfully reduced mobility and COVID-19 transmission across the US [[4]Dave D. Friedson A.I. Matsuzawa K. Sabia J.J. When do shelter-in-place orders fight COVID-19 best? Policy heterogeneity across states and adoption time.Econ Inq. 2020; https://doi.org/10.1111/ecin.12944Crossref PubMed Scopus (50) Google Scholar]. If we were to change policy or encourage less cautious private behavior, R0 would likely increase, and the herd immunity threshold would increase as well. Why does this matter for the future? Going forward, understanding how interactions among biology, behavior and policy affect outcomes will continue to be crucial for good policy design, while neglecting to consider how behavior may change in response to new interventions and policies may undermine progress. For example, recent weeks have brought positive news on vaccine development, including the approval and initial distribution of vaccines in several countries. In addition to saving many lives, the arrival of these vaccines will allow less restrictive policies, and vaccinated individuals will naturally and rationally increase their levels of activity as vaccination reduces risks to their health. On balance, this increase in activity will be welcome and beneficial. However, it will likely dampen some of the benefits of the vaccine, because increased activity will push R0 back up among those who are unlucky enough not to be protected by the vaccine. Since we will not know in advance who will have this bad luck, policy should continue to encourage low-cost mitigation, such as masking, ventilation of indoor spaces, and modest physical distancing, and policymakers should be cautious about lifting restrictions on large gatherings, especially indoors. On an even more basic level, the change in behavior could even undermine the level of protection the vaccine provides. In the double-blind placebo-controlled field trials of these vaccines, vaccine recipients still had a strong incentive to protect themselves and limit their own exposure, for two reasons. First, they did not know whether they had received the vaccine rather than the placebo. Second, at the time, it was not yet known that the vaccine would be effective. In contrast, an individual who knows she has received an approved, effective vaccine may reasonably and rationally take fewer precautions. The result is that early individuals to receive a vaccine may actually face higher levels of viral exposure than the experimental population did, since their behavior may change while, at least at early stages of vaccination, the overall level of infection in the community has not yet been reduced. We do not know how the vaccine will perform in this new context, and the growing evidence that higher intensity of exposure is associated with more severe illness should make us cautious [[5]Gandhi M. Beyrer C. Goosby E. Masks do more than protect others during COVID-19: reducing the inoculum of SARS-CoV-2 to protect the wearer.J Gen Intern Med. 2020; 35: 3063-3066Crossref PubMed Scopus (83) Google Scholar]. Again, public communication and policy should continue to encourage basic, low-cost protections to the extent possible, and will need to balance encouraging vaccine takeup with reminders not to abandon basic precautions. In particular, we suggest it will be useful to emphasize the “layers” mental model: [[6]Reason J. The contribution of latent human failures to the breakdown of complex systems.Philos Trans R Soc Lond B Biol Sci. 1990; 327: 475-484Crossref PubMed Scopus (380) Google Scholar] vaccines add an additional layer of protection. This additional layer may allow us to remove some existing layers that are especially burdensome, but should not lead us to remove all other layers, especially those which are low cost. This caution is especially necessary in these early stages because it is not yet clear that these vaccines provide sterilizing immunity. That is, even though the results of major trials have shown that the vaccines reduce illness, it is not known whether, or to what extent, they prevent infection and ongoing transmission [[7]Peiris M. Leung G.M. What can we expect from first-generation COVID-19 vaccines?.Lancet. 2020; 396: 1467-1469Summary Full Text Full Text PDF PubMed Scopus (45) Google Scholar]. Some data suggest a reduction in infection from at least one of the vaccines [[8]ModernaTX Inc. mRNA-1273 sponsor briefing document addendum. https://www.fda.gov/media/144453/download. Accessed online 18 Dec 2020.Google Scholar], which is positive news, but these are preliminary results and need further data and study before we can be confident. If the vaccine does not provide significant sterilizing immunity, then individuals or sub-groups who a vaccine does not protect, or who choose not to be vaccinated, will still be at serious risk. In fact, the risk to these groups may be even greater than it is without a vaccine, since the less cautious behavior of others may accelerate transmission [[9]The LancetCOVID-19 vaccines: no time for complacency.Lancet. 2020; 396: 1607Summary Full Text Full Text PDF PubMed Scopus (23) Google Scholar]. That is, to the extent that a vaccine prevents infection and onward transmission, it produces a positive externality: by vaccinating yourself, you make others safer. However, to the extent that it induces less cautious behavior, it may create a negative externality. On balance, of course, vaccines are overwhelmingly beneficial, but we can guard against the possibility of this negative unintended consequence by maintaining basic protections. This question of whether, and to what extent, these vaccines provide immunity – as opposed to just protection – is vitally important. Careful monitoring of those who have been vaccinated in trials, as well as a sample of those who receive early vaccines, is urgently needed to provide data on this crucial question. In addition to continuing to collect infection rates among trial participants [[8]ModernaTX Inc. mRNA-1273 sponsor briefing document addendum. https://www.fda.gov/media/144453/download. Accessed online 18 Dec 2020.Google Scholar], data on non-participating members of their households can inform the question of whether vaccination prevents transmission within households [[10]Ali M. Emch M. von Seidlein L. et al.Herd immunity conferred by killed oral cholera vaccines in Bangladesh: a reanalysis.Lancet. 2005; 366: 44-49Summary Full Text Full Text PDF PubMed Scopus (245) Google Scholar]. While it is reasonable to lift the highest-cost restrictions, such as school closures, before this question is resolved, policy and communication should continue to encourage low-cost protections like mask-wearing, and medium-cost interventions like improved ventilation and air filtration, especially in schools. This cautious approach will likely delay the safe return of valued services like indoor dining. Compensating affected workers and business owners will soften the economic impact of this caution and may reduce political resistance. Dr. Ercumen reports grants from Bill & Melinda Gates Foundation, outside the submitted work. All other authors report nothing.}, journal={EClinicalMedicine}, publisher={Elsevier BV}, author={Ercumen, Ayse and Guiteras, Raymond and Spears, Dean}, year={2021}, month={Jan}, pages={100719} }
 @article{slobodiuk_niven_arthur_thakur_ercumen_2021, title={Does Irrigation with Treated and Untreated Wastewater Increase Antimicrobial Resistance in Soil and Water: A Systematic Review}, DOI={10.3390/ijerph182111046}, abstractNote={Population growth and water scarcity necessitate alternative agriculture practices, such as reusing wastewater for irrigation. Domestic wastewater has been used for irrigation for centuries in many historically low-income and arid countries and is becoming more widely used by high-income countries to augment water resources in an increasingly dry climate. Wastewater treatment processes are not fully effective in removing all contaminants, such as antimicrobial resistant bacteria (ARB) and antimicrobial resistance genes (ARGs). Literature reviews on the impact of wastewater irrigation on antimicrobial resistance (AMR) in the environment have been inconclusive and mostly focused on treated wastewater. We conducted the first systematic review to assess the impact of irrigation with both treated or untreated domestic wastewater on ARB and ARGs in soil and adjacent water bodies. We screened titles/abstracts of 3002 articles, out of which 41 were screened in full text and 26 were included in this review. Of these, thirteen investigated irrigation with untreated wastewater, and nine found a positive association with ARB/ARGs in soil. Out of thirteen studies focused on treated wastewater, six found a positive association with ARB/ARGs while six found mixed/negative associations. Our findings demonstrate that irrigation with untreated wastewater increases AMR in soil and call for precautionary action by field workers, their families, and consumers when untreated wastewater is used to irrigate crops. The effect of irrigation with treated wastewater was more variable among the studies included in our review, highlighting the need to better understand to what extent AMR is disseminated through this practice. Future research should assess factors that modify the effect of wastewater irrigation on AMR in soil, such as the degree and type of wastewater treatment, and the duration and intensity of irrigation, to inform guidelines on the reuse of wastewater for irrigation.}, journal={INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH}, author={Slobodiuk, Stacy and Niven, Caitlin and Arthur, Greer and Thakur, Siddhartha and Ercumen, Ayse}, year={2021}, month={Nov} }
 @article{kwong_sen_islam_shahriar_benjamin-chung_arnold_hubbard_parvez_islam_unicomb_et al._2021, title={Effect of sanitation improvements on soil-transmitted helminth eggs in courtyard soil from rural Bangladesh: Evidence from a cluster-randomized controlled trial}, volume={15}, ISSN={["1935-2735"]}, DOI={10.1371/journal.pntd.0008815}, abstractNote={Improved sanitation has been hypothesized to reduce soil-transmitted helminth (STH) infections by reducing the prevalence and concentration of STH eggs/larvae in soil. We evaluated the effect of a randomized sanitation program (providing households with an improved dual-pit latrine, tools for child/animal feces management, and behavioral messaging) on reducing the prevalence and concentration of STH eggs in soil from household courtyards. We collected soil samples from 1405 households enrolled in the sanitation intervention (n = 419) and control (n = 914) groups of a cluster-randomized controlled trial (WASH Benefits) in rural Bangladesh approximately 2 years after the initiation of the interventions. We analyzed samples for Ascaris lumbricoides, Trichuris trichiura, and hookworm eggs by microscopy. We estimated prevalence ratios (PR) and egg count ratio (ECR) to compare the prevalence of STH eggs and arithmetic and geometric mean egg counts for STH eggs per gram of soil in the sanitation and control arms. Among intervention households, latrines achieved high and sustained user uptake by adults while child open defecation remained common and most households did not dispose of child feces hygienically. In courtyard soil from control households, the prevalence of any STH eggs was 75.7% and the prevalence of any larvated STH eggs was 67.3%. A. lumbricoides was detected in 63.0% of control samples and T. trichiura in 55.7% of control samples; hookworm was not detected in any sample. In the control arm, the arithmetic mean egg count for any STH was 3.96 eggs/dry gram, while the geometric mean was 1.58 eggs/dry gram. There was no difference between the intervention and control groups in the prevalence of any STH eggs (PR = 0.98 (95% CI: 0.91, 1.05)) or mean egg counts (ECR = 0.08 (95% CI: -0.10, 0.26) for geometric mean and 0.07 (95% CI: -0.22, 0.37) for arithmetic mean). Adjusted models gave similar results. A compound-level sanitation intervention that provided improved latrines and tools for disposal of child and animal feces did not have an impact on STH eggs in soil. In order to effectively reduce the prevalence and concentration of STH eggs in the environment, sustained, widespread use of sanitation strategies to isolate and hygienically dispose of child and animal feces may need to complement traditional strategies for containment of adult human feces.}, number={7}, journal={PLOS NEGLECTED TROPICAL DISEASES}, author={Kwong, Laura H. and Sen, Debashis and Islam, Sharmin and Shahriar, Sunny and Benjamin-Chung, Jade and Arnold, Benjamin F. and Hubbard, Alan and Parvez, Sarker Masud and Islam, Mahfuza and Unicomb, Leanne and et al.}, year={2021}, month={Jul} }
 @article{alam_ferdous_ercumen_lin_kamal_luies_sharior_khan_rahman_parvez_et al._2021, title={Effective Treatment Strategies for the Removal of Antibiotic-Resistant Bacteria, Antibiotic-Resistance Genes, and Antibiotic Residues in the Effluent From Wastewater Treatment Plants Receiving Municipal, Hospital, and Domestic Wastewater: Protocol for a Systematic Review}, DOI={10.2196/33365}, abstractNote={
            Background
            The widespread and unrestricted use of antibiotics has led to the emergence and spread of antibiotic-resistant bacteria (ARB), antibiotic-resistance genes (ARGs), and antibiotic residues in the environment. Conventional wastewater treatment plants (WWTPs) are not designed for effective and adequate removal of ARB, ARGs, and antibiotic residues, and therefore, they play an important role in the dissemination of antimicrobial resistance (AMR) in the natural environment.
          }, journal={JMIR RESEARCH PROTOCOLS}, author={Alam, Mahbub-Ul and Ferdous, Sharika and Ercumen, Ayse and Lin, Audrie and Kamal, Abul and Luies, Sharmin Khan and Sharior, Fazle and Khan, Rizwana and Rahman, Md Ziaur and Parvez, Sarker Masud and et al.}, year={2021}, month={Nov} }
 @article{islam_benjamin-chung_sultana_unicomb_alam_rahman_ercumen_luby_2021, title={Effectiveness of Mass Media Campaigns to Improve Handwashing-Related Behavior, Knowledge, and Practices in Rural Bangladesh}, volume={104}, ISSN={["1476-1645"]}, DOI={10.4269/ajtmh.20-1154}, abstractNote={ABSTRACT}, number={4}, journal={AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE}, author={Islam, Mahfuza and Benjamin-Chung, Jade and Sultana, Sonia and Unicomb, Leanne and Alam, Monirul and Rahman, Mahbubur and Ercumen, Ayse and Luby, Stephen P.}, year={2021}, month={Apr}, pages={1546–1553} }
 @article{workman_stoler_harris_ercumen_kearns_mapunda_2021, title={Food, water, and sanitation insecurities: Complex linkages and implications for achieving WASH security}, volume={9}, ISSN={["1744-1706"]}, url={https://doi.org/10.1080/17441692.2021.1971735}, DOI={10.1080/17441692.2021.1971735}, abstractNote={ABSTRACT Food, water and sanitation insecurities are complex, multi-dimensional phenomena that entail more than availability and access; food, water, and sanitation resources must be safe and culturally appropriate. Researchers and implementers concerned with these insecurities have demonstrated that there are notable interactions between them resulting in significant psychological and biological outcomes. Recent randomised controlled trials (RCTs) in Bangladesh, Kenya (WASH Benefits) and Zimbabwe (SHINE) demonstrated no effect from water, sanitation and hygiene (WASH) interventions on linear growth, and mixed evidence on enteropathogen burden and risk of diarrhoea in young children. These data suggest a need for a more comprehensive understanding of WASH security. The risks posed by multiple resource insecurities shift depending on the individual, their movement throughout their day, their economically and socially prescribed roles, and ecological features such as seasonality and precipitation. By more fully integrating food, water and sanitation security in interventions and subsequent impact evaluations, we can achieve WASH security—one that addresses myriad transmission pathways and co-occurring diseases—that ultimately would improve health outcomes throughout the world. In this critical review, we outline the complexity of combined resource insecurities as a step towards transformative WASH.}, journal={GLOBAL PUBLIC HEALTH}, author={Workman, Cassandra L. and Stoler, Justin and Harris, Angela and Ercumen, Ayse and Kearns, Joshua and Mapunda, Kenneth M.}, year={2021}, month={Sep} }
 @article{benjamin-chung_crider_mertens_ercumen_pickering_lin_steinbaum_swarthout_rahman_parvez_et al._2021, title={Household finished flooring and soil-transmitted helminth and Giardia infections among children in rural Bangladesh and Kenya: a prospective cohort study}, volume={9}, url={http://dx.doi.org/10.1016/s2214-109x(20)30523-4}, DOI={10.1016/s2214-109x(20)30523-4}, abstractNote={Soil-transmitted helminths and Giardia duodenalis are responsible for a large burden of disease globally. In low-resource settings, household finished floors (eg, concrete floors) might reduce transmission of soil-transmitted helminths and G duodenalis.In a prospective cohort of children nested within two randomised trials in rural Bangladesh and Kenya, we estimated associations between household finished flooring and soil-transmitted helminths and G duodenalis prevalence. In 2015-16, we collected stool samples from children aged 2-16 years in rural Bangladesh and Kenya. We detected soil-transmitted helminth infection using quantitative PCR (qPCR; Bangladesh n=2800; Kenya n=3094), and G duodenalis using qPCR in Bangladesh (n=6894) and ELISA in Kenya (n=8899). We estimated adjusted prevalence ratios (aPRs) using log-linear models adjusted for potential confounders.7187 (92·2%) of 7795 children in Bangladesh and 9077 (93·7%) of 9686 children in Kenya provided stool specimens that were analysed by qPCR. At enrolment, 691 (10%) households in Bangladesh and 471 (5%) households in Kenya had finished floors. In both countries, household finished flooring was associated with lower Ascaris lumbricoides prevalence (Bangladesh aPR 0·33, 95% CI 0·14-0·78; Kenya 0·62, 0·39-0·98) and any soil-transmitted helminths (Bangladesh 0·73, 0·52-1·01; Kenya 0·57, 0·37-0·88). Household finished floors were also associated with lower Necator americanus prevalence in Bangladesh (0·52, 0·29-0·94) and G duodenalis prevalence in both countries (Bangladesh 0·78, 0·64-0·95; Kenya 0·82, 0·70-0·97).In low-resource settings, living in households with finished floors over a 2-year period was associated with lower prevalence of G duodenalis and some soil-transmitted helminths in children.Bill & Melinda Gates Foundation and Task Force for Global Health.}, number={3}, journal={The Lancet Global Health}, publisher={Elsevier BV}, author={Benjamin-Chung, Jade and Crider, Yoshika S and Mertens, Andrew and Ercumen, Ayse and Pickering, Amy J and Lin, Audrie and Steinbaum, Lauren and Swarthout, Jenna and Rahman, Mahbubur and Parvez, Sarker M and et al.}, year={2021}, month={Mar}, pages={e301–e308} }
 @article{contreras_islam_mertens_pickering_kwong_arnold_benjamin-chung_hubbard_alam_sen_et al._2021, title={Longitudinal Effects of a Sanitation Intervention on Environmental Fecal Contamination in a Cluster-Randomized Controlled Trial in Rural Bangladesh}, volume={55}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.1c01114}, abstractNote={Household latrine access generally is not associated with reduced fecal contamination in the environment, but its long-term effectiveness has not been measured. We conducted an environmental assessment nested within the WASH Benefits Bangladesh randomized controlled trial (NCT01590095). We quantified E. coli and fecal coliforms in samples of stored drinking water, child hands, mother hands, soil, and food among a random sample of households from the sanitation and control arms of the trial. Samples were collected during eight quarterly visits approximately 1–3.5 years after intervention initiation. Overall, there were no substantial differences in environmental fecal contamination between households enrolled in the sanitation and control arms. Statistically significant reductions were found in stored water and child hands after pooling across sampling rounds, but the effects were small and not consistent across rounds. In addition, we assessed potential effect modification of intervention effects by follow-up time, season, wealth, community-level latrine density and coverage, population density, and domestic animal ownership. While the intervention had statistically significant effects within some subgroups, there were no consistent patterns of effect modification. Our findings support a growing consensus that on-site latrines are insufficient to prevent fecal contamination in the rural household environment.}, number={12}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Contreras, Jesse D. and Islam, Mahfuza and Mertens, Andrew and Pickering, Amy J. and Kwong, Laura H. and Arnold, Benjamin F. and Benjamin-Chung, Jade and Hubbard, Alan E. and Alam, Mahfuja and Sen, Debashis and et al.}, year={2021}, month={Jun}, pages={8169–8179} }
 @article{kwong_ercumen_pickering_unicomb_davis_leckie_luby_2021, title={Soil ingestion among young children in rural Bangladesh}, volume={31}, ISSN={["1559-064X"]}, url={http://dx.doi.org/10.1038/s41370-019-0177-7}, DOI={10.1038/s41370-019-0177-7}, abstractNote={Ingestion of soil and dust is a pathway of children’s exposure to several environmental contaminants, including lead, pesticides, and fecal contamination. Empirically based estimates of central tendency for soil consumption by children in high-income countries range from 9 to 135 dry mg/day. Using a Monte Carlo simulation, we modeled the mass of soil directly and indirectly ingested per day by rural Bangladeshi children and identified the parameters that influence the mass ingested. We combined data from observations of direct and indirect ingestion among children with measurements of soil mass on the children’s hands, mother’s hands, and objects to quantify soil ingestion/day. Estimated geometric mean soil ingestion was 162 dry mg/day for children 3–5 months, 224 dry mg/day for children 6–11 months, 234 dry mg/day for children 12–23 months, 168 dry mg/day for children 24–35 months, and 178 dry mg/day for children 36–47 months old. Across all age groups, children placing their hands in their mouths accounted for 46–78% of total ingestion and mouthing objects contributed 8–12%. Direct ingestion of soil accounted for nearly 40% of soil ingested among children 6–23 months old. Sensitivity analyses identified that the parameters most affecting the estimates were the load of soil on the child’s hand, the frequency of hand-to-mouth contacts while not eating, and, for children 6–23 months old, the frequency of direct soil ingestion. In a rural, low-income setting, children’s soil consumption was substantially more than the estimates for children in high-income countries. Further characterizing soil ingestion of children in low-income contexts would improve assessments of the risks they face from soil-associated contaminants.}, number={1}, journal={JOURNAL OF EXPOSURE SCIENCE AND ENVIRONMENTAL EPIDEMIOLOGY}, publisher={Springer Science and Business Media LLC}, author={Kwong, Laura H. and Ercumen, Ayse and Pickering, Amy J. and Unicomb, Leanne and Davis, Jennifer and Leckie, James O. and Luby, Stephen P.}, year={2021}, month={Feb}, pages={82–93} }
 @article{kumpel_billava_nayak_ercumen_2021, title={Water use behaviors and water access in intermittent and continuous water supply areas during the COVID-19 pandemic}, volume={11}, ISSN={["1996-7829"]}, DOI={10.2166/wh.2021.184}, abstractNote={Abstract}, journal={JOURNAL OF WATER AND HEALTH}, author={Kumpel, Emily and Billava, Nayaran and Nayak, Nayanatara and Ercumen, Ayse}, year={2021}, month={Nov} }
 @article{kwong_ercumen_pickering_unicomb_davis_luby_2020, title={Age-related changes to environmental exposure: variation in the frequency that young children place hands and objects in their mouths}, volume={30}, ISSN={["1559-064X"]}, DOI={10.1038/s41370-019-0115-8}, abstractNote={Children are exposed to environmental contaminants through direct ingestion of water, food, soil, and feces, and through indirect ingestion owing to mouthing hands and objects. We quantified ingestion among 30 rural Bangladeshi children < 4 years old, recording every item touched or mouthed during 6-hour video observations that occurred annually for 3 years. We calculated the frequency and duration of mouthing and the prevalence of mouth contacts with soil and feces. We compared the mouthing frequency distributions to those from US children to evaluate the appropriateness of applying the US data to the Bangladeshi context. Median hand-mouthing frequency was 43-72 times/h and object-mouthing frequency 17-34 times/h among the five age groups assessed. For half of the observations, > 75% of all hand mouthing was associated with eating. The frequency of indoor hand mouthing not related to eating was similar to the frequency of all indoor hand mouthing among children in the United States. Object-mouthing frequency was higher among Bangladeshi children compared with US children. There was low intra-child correlation of mouthing frequencies over our longitudinal visits. Our results suggest that children's hand- and object-mouthing vary by geography and culture and that future exposure assessments can be cross-sectional if the goal is to estimate population-level distributions of mouthing frequencies. Of all observations, a child consumed soil in 23% and feces in 1%.}, number={1}, journal={JOURNAL OF EXPOSURE SCIENCE AND ENVIRONMENTAL EPIDEMIOLOGY}, author={Kwong, Laura H. and Ercumen, Ayse and Pickering, Amy J. and Unicomb, Leanne and Davis, Jennifer and Luby, Stephen P.}, year={2020}, month={Jan}, pages={205–216} }
 @article{kwong_ercumen_pickering_unicomb_davis_luby_2020, title={Age-related changes to environmental exposure: variation in the frequency that young children place hands and objects in their mouths (vol 17, pg 631, 2019)}, volume={30}, ISSN={["1559-064X"]}, DOI={10.1038/s41370-019-0160-3}, abstractNote={An amendment to this paper has been published and can be accessed via a link at the top of the paper.}, number={4}, journal={JOURNAL OF EXPOSURE SCIENCE AND ENVIRONMENTAL EPIDEMIOLOGY}, author={Kwong, Laura H. and Ercumen, Ayse and Pickering, Amy J. and Unicomb, Leanne and Davis, Jennifer and Luby, Stephen P.}, year={2020}, month={Jul}, pages={769–772} }
 @article{islam_rahman_unicomb_kafi_rahman_alam_sen_islam_pickering_hubbard_et al._2020, title={Child defecation and feces management practices in rural Bangladesh: Associations with fecal contamination, observed hand cleanliness and child diarrhea}, volume={15}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0236163}, abstractNote={Child open defecation is common in low-income countries and can lead to fecal exposure in the domestic environment. We assessed associations between child feces management practices vs. measures of contamination and child diarrhea among households with children <5 years in rural Bangladesh. We visited 360 households quarterly and recorded caregiver-reported diarrhea prevalence, and defecation and feces disposal practices for children <5 years. We examined caregiver and child hands for visible dirt and enumerated E. coli in child and caregiver hand rinse and stored drinking water samples. Safe child defecation (in latrine/potty) and safe feces disposal (in latrine) was reported by 21% and 23% of households, respectively. Controlling for potential confounders, households reporting unsafe child defecation had higher E. coli prevalence on child hands (prevalence ratio [PR] = 1.12, 1.04–1.20) and in stored water (PR = 1.12,1.03–1.21). Similarly, households reporting unsafe feces disposal had higher E. coli prevalence on child hands (PR = 1.11, 1.02–1.21) and in stored water (PR = 1.10, 1.03–1.18). Effects on E. coli levels were similar. Children in households with unsafe defecation and feces disposal had higher diarrhea prevalence but the associations were not statistically significant. Our findings suggest that unsafe child feces management may present a source of fecal exposure for young children.}, number={7}, journal={PLOS ONE}, author={Islam, Mahfuza and Rahman, Mahbubur and Unicomb, Leanne and Kafi, Mohammad Abdullah Heel and Rahman, Mostafizur and Alam, Mahfuja and Sen, Debashis and Islam, Sharmin and Pickering, Amy J. and Hubbard, Alan E. and et al.}, year={2020}, month={Jul} }
 @article{benjamin-chung_pilotte_ercumen_grant_maasch_gonzalez_ester_arnold_rahman_haque_et al._2020, title={Comparison of multi-parallel qPCR and double-slide Kato-Katz for detection of soil-transmitted helminth infection among children in rural Bangladesh}, volume={14}, ISSN={["1935-2735"]}, DOI={10.1371/journal.pntd.0008087}, abstractNote={There is growing interest in local elimination of soil-transmitted helminth (STH) infection in endemic settings. In such settings, highly sensitive diagnostics are needed to detect STH infection. We compared double-slide Kato-Katz, the most commonly used copromicroscopic detection method, to multi-parallel quantitative polymerase chain reaction (qPCR) in 2,799 stool samples from children aged 2–12 years in a setting in rural Bangladesh with predominantly low STH infection intensity. We estimated the sensitivity and specificity of each diagnostic using Bayesian latent class analysis. Compared to double-slide Kato-Katz, STH prevalence using qPCR was almost 3-fold higher for hookworm species and nearly 2-fold higher for Trichuris trichiura. Ascaris lumbricoides prevalence was lower using qPCR, and 26% of samples classified as A. lumbricoides positive by Kato-Katz were negative by qPCR. Amplicon sequencing of the 18S rDNA from 10 samples confirmed that A. lumbricoides was absent in samples classified as positive by Kato-Katz and negative by qPCR. The sensitivity of Kato-Katz was 49% for A. lumbricoides, 32% for hookworm, and 52% for T. trichiura; the sensitivity of qPCR was 79% for A. lumbricoides, 93% for hookworm, and 90% for T. trichiura. Specificity was ≥ 97% for both tests for all STH except for Kato-Katz for A. lumbricoides (specificity = 68%). There were moderate negative, monotonic correlations between qPCR cycle quantification values and eggs per gram quantified by Kato-Katz. While it is widely assumed that double-slide Kato-Katz has few false positives, our results indicate otherwise and highlight inherent limitations of the Kato-Katz technique. qPCR had higher sensitivity than Kato-Katz in this low intensity infection setting.}, number={4}, journal={PLOS NEGLECTED TROPICAL DISEASES}, author={Benjamin-Chung, Jade and Pilotte, Nils and Ercumen, Ayse and Grant, Jessica R. and Maasch, Jacqueline R. M. A. and Gonzalez, Andrew M. and Ester, Ashanta C. and Arnold, Benjamin F. and Rahman, Mahbubur and Haque, Rashidul and et al.}, year={2020}, month={Apr} }
 @article{fuhrmeister_ercumen_pickering_jeanis_crider_ahmed_brown_alam_sen_islam_et al._2020, title={Effect of Sanitation Improvements on Pathogens and Microbial Source Tracking Markers in the Rural Bangladeshi Household Environment}, volume={54}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.9b04835}, abstractNote={Diarrheal illnesses from enteric pathogens are a leading cause of death in children under five in low- and middle-income countries (LMICs). Sanitation is one way to reduce the spread of enteric pathogens in the environment; however, few studies have investigated the effectiveness of sanitation in rural LMICs in reducing pathogens in the environment. In this study, we measured the impact of a sanitation intervention (dual-pit latrines, sani-scoops, child potties delivered as part of a randomized control trial, WASH Benefits) in rural Bangladeshi household compounds by assessing prevalence ratios, differences, and changes in the concentration of pathogen genes and host-specific fecal markers. We found no difference in the prevalence of pathogenic Escherichia coli, norovirus, or Giardia genes in the domestic environment in the sanitation and control arms. The prevalence of the human fecal marker was lower on child hands and the concentration of animal fecal marker was lower on mother hands in the sanitation arm in adjusted models, but these associations were not significant after correcting for multiple comparisons. In the subset of households with ≥10 individuals per compound, the prevalence of enterotoxigenic E. coli genes on child hands was lower in the sanitation arm. Incomplete removal of child and animal feces or the compound (versus community-wide) scale of intervention could explain the limited impacts of improved sanitation.}, number={7}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Fuhrmeister, Erica R. and Ercumen, Ayse and Pickering, Amy J. and Jeanis, Kaitlyn M. and Crider, Yoshika and Ahmed, Mahaa and Brown, Sara and Alam, Mahfuja and Sen, Debashis and Islam, Sharmin and et al.}, year={2020}, month={Apr}, pages={4316–4326} }
 @article{goddard_pickering_ercumen_brown_chang_clasen_2020, title={Faecal contamination of the environment and child health: a systematic review and individual participant data meta-analysis}, volume={4}, url={http://dx.doi.org/10.1016/s2542-5196(20)30195-9}, DOI={10.1016/s2542-5196(20)30195-9}, abstractNote={<h2>Summary</h2><h3>Background</h3> Exposure to faecal contamination is believed to be associated with child diarrhoea and possibly stunting; however, few studies have explicitly measured the association between faecal contamination and health. We aimed to assess individual participant data (IPD) across multiple trials and observational studies to quantify the relationship for common faecal–oral transmission pathways. <h3>Methods</h3> We did a systematic review and meta-analysis of IPD from studies identified in an electronic search of PubMed, Web of Science, and Embase on May 21, 2018. The search was done in English, but full texts published in French, Portuguese, and Spanish were also reviewed. Eligible studies quantified (1) household-level faecal indicator bacteria concentrations along common faecal-oral transmission pathways of drinking water, soil, or food, on children's hands or fomites, or fly densities in food preparation areas; and (2) individual-level diarrhoea or linear growth measures for children younger than 5 years in low-income and middle-income countries. For the diarrhoea analysis, all definitions of diarrhoea were eligible but studies were excluded if they used a recall period longer than 7 days. For the linear growth analysis (using height-for-age Z scores [HAZ]), cross-sectional studies were excluded, because of the absence of longitudinal environmental contamination data measured before the growth outcomes. We used multilevel generalised mixed-effects models to estimate the odds ratio (OR) for diarrhoea and the difference in HAZ scores for individual studies associated with a 1-log<sub>10</sub> higher measure of faecal contamination. Estimates from each study were combined under a random-effects meta-analysis framework. The study protocol was pre-registered with PROSPERO (CRD42018102114). <h3>Findings</h3> From 72 eligible studies, we included IPD for 20 studies in the meta-analyses, totalling 54 225 diarrhoea or linear growth observations matched to faecal indicator bacteria concentrations in drinking water, and a further 35 010 observations with faecal contamination data for the other transmission pathways. Child diarrhoea was associated with 1-log<sub>10</sub> higher faecal indicator bacteria concentrations in drinking water (OR 1·09, 95% CI 1·04 to 1·13; p=0·0002, <i>I</i><sup>2</sup>=34%, 95% CI 0 to 62) and on children's hands (1·11, 1·02 to 1·22; p=0·021, <i>I</i><sup>2</sup>=0%, 0 to 71). Lower HAZ scores were associated with 1-log<sub>10</sub> higher median faecal indicator bacteria concentrations in drinking water (HAZ −0·04, 95% CI −0·06 to −0·01; p=0·0054; <i>I</i><sup>2</sup>=19%, 95% CI 0 to 63) and on fomites (–0·06, −0·12 to 0·00; p=0·044, <i>I</i><sup>2</sup>=57%, 0 to 90). <h3>Interpretation</h3> Although summary measures from individual studies often report little or no effect of measured faecal contamination on child health, this multi-study IPD analysis indicates that household faecal indicator bacteria concentrations are associated with important adverse health outcomes in young children. Improved direct measures of exposure and enteric pathogens could help to better characterise the relationship and inform intervention design in future studies. <h3>Funding</h3> None.}, number={9}, journal={The Lancet Planetary Health}, publisher={Elsevier BV}, author={Goddard, Frederick G B and Pickering, Amy J and Ercumen, Ayse and Brown, Joe and Chang, Howard H and Clasen, Thomas}, year={2020}, month={Sep}, pages={e405–e415} }
 @article{kwong_ercumen_pickering_arsenault_islam_parvez_unicomb_rahman_davis_luby_2020, title={Ingestion of Fecal Bacteria along Multiple Pathways by Young Children in Rural Bangladesh Participating in a Cluster-Randomized Trial of Water, Sanitation, and Hygiene Interventions (WASH Benefits)}, volume={54}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.0c02606}, abstractNote={Quantifying the contribution of individual exposure pathways to a child’s total ingestion of fecal matter could help prioritize interventions to reduce environmental enteropathy and diarrhea. This study used data on fecal contamination of drinking water, food, soil, hands, and objects and second-by-second data on children’s contacts with these environmental reservoirs in rural Bangladesh to assess the relative contribution of different pathways to children’s ingestion of fecal indicator bacteria and if ingestion decreased with the water, sanitation, and hygiene interventions implemented in the WASH Benefits Trial. Our model estimated that rural Bangladeshi children <36 months old consume 3.6–4.9 log10 most probable number E. coli/day. Among children <6 months, placing objects in the mouth accounted for 60% of E. coli ingested. For children 6–35 months old, mouthing their own hands, direct soil ingestion, and ingestion of contaminated food were the primary pathways of E. coli ingestion. The amount of E. coli ingested by children and the predominant pathways of E. coli ingestion were unchanged by the water, sanitation, and hygiene interventions. These results highlight contaminated soil, children’s hands, food, and objects as primary pathways of E. coli ingestion and emphasize the value of intervening along these pathways.}, number={21}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Kwong, Laura H. and Ercumen, Ayse and Pickering, Amy J. and Arsenault, Joanne E. and Islam, Mahfuza and Parvez, Sarker M. and Unicomb, Leanne and Rahman, Mahbubur and Davis, Jennifer and Luby, Stephen P.}, year={2020}, month={Nov}, pages={13828–13838} }
 @article{goddard_ban_barr_brown_cannon_colford_eisenberg_ercumen_petach_freeman_et al._2020, title={Measuring Environmental Exposure to Enteric Pathogens in Low-Income Settings: Review and Recommendations of an Interdisciplinary Working Group}, volume={54}, ISBN={1520-5851}, DOI={10.1021/acs.est.0c02421}, abstractNote={Infections with enteric pathogens impose a heavy disease burden, especially among young children in low-income countries. Recent findings from randomized controlled trials of water, sanitation, and hygiene interventions have raised questions about current methods for assessing environmental exposure to enteric pathogens. Approaches for estimating sources and doses of exposure suffer from a number of shortcomings, including reliance on imperfect indicators of fecal contamination instead of actual pathogens and estimating exposure indirectly from imprecise measurements of pathogens in the environment and human interaction therewith. These shortcomings limit the potential for effective surveillance of exposures, identification of important sources and modes of transmission, and evaluation of the effectiveness of interventions. In this review, we summarize current and emerging approaches used to characterize enteric pathogen hazards in different environmental media as well as human interaction with those media (external measures of exposure), and review methods that measure human infection with enteric pathogens as a proxy for past exposure (internal measures of exposure). We draw from lessons learned in other areas of environmental health to highlight how external and internal measures of exposure can be used to more comprehensively assess exposure. We conclude by recommending strategies for advancing enteric pathogen exposure assessments.}, number={19}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Goddard, Frederick G. B. and Ban, Radu and Barr, Dana Boyd and Brown, Joe and Cannon, Jennifer and Colford, John M., Jr. and Eisenberg, Joseph N. S. and Ercumen, Ayse and Petach, Helen and Freeman, Matthew C. and et al.}, year={2020}, pages={11673–11691} }
 @article{ercumen_prottas_harris_dioguardi_dowd_guiteras_2020, title={Poultry Ownership Associated with Increased Risk of Child Diarrhea: Cross-Sectional Evidence from Uganda}, volume={102}, ISSN={0002-9637 1476-1645}, url={http://dx.doi.org/10.4269/ajtmh.19-0012}, DOI={10.4269/ajtmh.19-0012}, abstractNote={Abstract. Domestic animals have been associated with enteric infections in young children and can also be carriers of respiratory viruses. We conducted a cross-sectional assessment of health outcomes in children aged < 5 years associated with animal presence among 793 rural households in Uganda. We recorded the 2-week prevalence of diarrhea and respiratory infections in children, and the number of cows, poultry, sheep/goats, and pigs in the household. We used generalized linear models with robust standard errors to estimate the prevalence ratio (PR) for diarrhea and respiratory infections associated with households owning the above- versus below-median number of animals. We conducted unadjusted and adjusted analyses controlling for socioeconomic, water, sanitation, and hygiene indicators. Children in households with the above-median number (> 5) of poultry had 83% higher diarrhea prevalence than those with ≤ 5 poultry (adjusted PR = 1.83 [1.04, 3.23], P = 0.04). Children in households with the above-median number (> 2) of cows had 48% lower prevalence of respiratory infection than those with ≤ 2 cows (adjusted PR = 0.52 [0.35, 0.76], P < 0.005). There were no other significant associations between domestic animals and child health. Studies should assess if barring chickens from indoor living quarters and sanitary disposal of chicken and other animal feces can reduce childhood zoonotic infections.}, number={3}, journal={The American Journal of Tropical Medicine and Hygiene}, publisher={American Society of Tropical Medicine and Hygiene}, author={Ercumen, Ayse and Prottas, Chris and Harris, Angela and Dioguardi, Angelique and Dowd, Greg and Guiteras, Raymond}, year={2020}, month={Mar}, pages={526–533} }
 @article{fuhrmeister_ercumen_grembi_islam_pickering_nelson_2020, title={Shared bacterial communities between soil, stored drinking water, and hands in rural Bangladeshi households}, volume={9}, ISSN={["2589-9147"]}, DOI={10.1016/j.wroa.2020.100056}, abstractNote={Understanding household-level transmission pathways of fecal pathogens can provide insight for developing effective strategies to reduce diarrheal illness in low- and middle-income countries. We applied whole bacterial community analysis to investigate pathways of bacterial transmission in 50 rural Bangladeshi households. SourceTracker was used to quantify the shared microbial community in household reservoirs (stored drinking water, soil, and hands) and estimate the percentage of fecal-associated bacteria from child and mothers' feces in these reservoirs. Among the reservoirs studied, most bacterial transfer occurred between mothers' and children's hands and between mothers' hands and stored water. The relative percentage of human fecal-associated bacteria in all household reservoirs was low. We also quantified the number of identical amplicon sequence variants within and between individual households to assess bacterial community exchange in the domestic environment. Intra-household sharing of bacteria between mothers' and children's hands and between hands and soil was significantly greater than inter-household sharing.}, journal={WATER RESEARCH X}, author={Fuhrmeister, Erica R. and Ercumen, Ayse and Grembi, Jessica A. and Islam, Mahfuza and Pickering, Amy J. and Nelson, Kara L.}, year={2020}, month={Dec} }
 @article{poulin_peletz_ercumen_pickering_marshall_boehm_khush_delaire_2020, title={What Environmental Factors Influence the Concentration of Fecal Indicator Bacteria in Groundwater? Insights from Explanatory Modeling in Uganda and Bangladesh}, volume={54}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.0c02567}, abstractNote={Information about microbial water quality is critical for managing water safety and protecting public health. In low-income countries, monitoring all drinking water supplies is impractical because financial resources and capacity are insufficient. Datasets derived from satellite imagery, census, and hydrological models provide an opportunity to examine relationships between a suite of environmental risk factors and microbial water quality over large geographical scales. We investigated the relationships between groundwater fecal contamination and different environmental parameters in Uganda and Bangladesh. In Uganda, groundwater contamination was associated with high population density (p<0.001; OR=1.27), high cropland coverage (p<0.001; OR=1.47), high average monthly precipitation (p<0.001; OR=1.14), and high surface runoff (p<0.001; OR=1.37), while low groundwater contamination was more likely in areas further from cities (p<0.001; OR=0.66) and with higher forest coverage (p<0.001; OR=0.70). In Bangladesh, contamination was associated with higher weekly precipitation (p<0.001; OR=1.42) and higher livestock density (p=0.05; OR=1.11), while low contamination was associated with low forest coverage (p<0.001; OR=1.23) and low cropland coverage (p<0.001; OR=0.80). We developed a groundwater contamination index for each country to help decision-makers identify areas where groundwater is most prone to fecal contamination and prioritize monitoring activities. Our approach demonstrates how to harness satellite-derived data to guide water safety management.}, number={21}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Poulin, Chloe and Peletz, Rachel and Ercumen, Ayse and Pickering, Amy J. and Marshall, Katherine and Boehm, Alexandria B. and Khush, Ranjiv and Delaire, Caroline}, year={2020}, month={Nov}, pages={13566–13578} }
 @article{lin_ali_arnold_rahman_alauddin_grembi_mertens_famida_akther_hossen_et al._2019, title={Effects of Water, Sanitation, Handwashing, and Nutritional Interventions on Environmental Enteric Dysfunction in Young Children: A Cluster-randomized, Controlled Trial in Rural Bangladesh}, volume={4}, url={http://dx.doi.org/10.1093/cid/ciz291}, DOI={10.1093/cid/ciz291}, abstractNote={BACKGROUND
We hypothesized that drinking water, sanitation, handwashing (WSH) and nutritional interventions would improve environmental enteric dysfunction (EED), a potential contributor to stunting.


METHODS
Within a subsample of a cluster-randomized controlled trial in rural Bangladesh, we enrolled pregnant women in four arms: control, combined WSH, child nutrition counseling plus lipid-based nutrient supplements (N), and combined nutrition plus WSH (N+WSH). Among the birth cohort, we measured biomarkers of gut inflammation (myeloperoxidase, neopterin), permeability (alpha-1-antitrypsin, lactulose, mannitol), and repair (regenerating gene 1β) at median ages 3, 14, and 28 months. Analysis was intention-to-treat.


RESULTS
We assessed 1512 children. At age 3 months, compared to controls, neopterin was reduced by nutrition (-0.21 log nmol/L, CI -0.37, -0.05) and N+WSH (-0.20 log nmol/L, CI -0.34, -0.06) interventions; similar reductions were observed at 14 months. At 3 months, all interventions reduced lactulose and mannitol (-0.60 to -0.69 log mmol/L). At 28 months, myeloperoxidase was elevated in the WSH (0.23 log ng/ml, CI 0.06, 0.39) and nutrition (0.27 log ng/ml, CI 0.07, 0.47) arms and lactulose was higher in the WSH arm (0.30 log mmol/L, CI 0.07, 0.53).


CONCLUSIONS
Reductions in permeability and inflammation at ages 3 and 14 months suggest that the interventions promoted healthy intestinal maturation; however, by 28 months the WSH and nutrition arms showed elevated EED biomarkers. These results underscore the importance of better understanding the pathophysiology of EED and targeting interventions early in childhood during the critical period when they are likely to have the largest benefit to intestinal health.(ClinicalTrials.gov NCT01590095).}, journal={Clinical Infectious Diseases}, publisher={Oxford University Press (OUP)}, author={Lin, Audrie and Ali, Shahjahan and Arnold, Benjamin F and Rahman, Md Ziaur and Alauddin, Mohammad and Grembi, Jessica and Mertens, Andrew N and Famida, Syeda L and Akther, Salma and Hossen, Md Saheen and et al.}, year={2019}, month={Apr} }
 @article{stewart_dewey_lin_pickering_byrd_jannat_ali_rao_dentz_kiprotich_et al._2019, title={Effects of lipid-based nutrient supplements and infant and young child feeding counseling with or without improved water, sanitation, and hygiene (WASH) on anemia and micronutrient status: results from 2 cluster-randomized trials in Kenya and Bangladesh}, volume={1}, ISSN={1938-3207}, DOI={10.1093/ajcn/nqy239}, abstractNote={ABSTRACT Background Anemia in young children is a global health problem. Risk factors include poor nutrient intake and poor water quality, sanitation, or hygiene. Objective We evaluated the effects of water quality, sanitation, handwashing, and nutrition interventions on micronutrient status and anemia among children in rural Kenya and Bangladesh. Design We nested substudies within 2 cluster-randomized controlled trials enrolling pregnant women and following their children for 2 y. These substudies included 4 groups: water, sanitation, and handwashing (WSH); nutrition (N), including lipid-based nutrient supplements (LNSs; ages 6–24 mo) and infant and young child feeding (IYCF) counseling; WSH+N; and control. Hemoglobin and micronutrient biomarkers were measured after 2 y of intervention and compared between groups using generalized linear models with robust SEs. Results In Kenya, 699 children were assessed at a mean ± SD age of 22.1 ± 1.8 mo, and in Bangladesh 1470 participants were measured at a mean ± SD age of 28.0 ± 1.9 mo. The control group anemia prevalences were 48.8% in Kenya and 17.4% in Bangladesh. There was a lower prevalence of anemia in the 2 N intervention groups in both Kenya [N: 36.2%; prevalence ratio (PR): 0.74; 95% CI: 0.58, 0.94; WSH+N: 27.3%; PR: 0.56; 95% CI: 0.42, 0.75] and Bangladesh (N: 8.7%; PR: 0.50; 95% CI: 0.32, 0.78; WSH+N: 7.9%, PR: 0.46; 95% CI: 0.29, 0.73). In both trials, the 2 N groups also had significantly lower prevalences of iron deficiency, iron deficiency anemia, and low vitamin B-12 and, in Kenya, a lower prevalence of folate and vitamin A deficiencies. In Bangladesh, the WSH group had a lower prevalence of anemia (12.8%; PR: 0.74; 95% CI: 0.54, 1.00) than the control group, whereas in Kenya, the WSH+N group had a lower prevalence of anemia than did the N group (PR: 0.75; 95% CI: 0.53, 1.07), but this was not significant (P = 0.102). Conclusions IYCF counseling with LNSs reduced the risks of anemia, iron deficiency, and low vitamin B-12. Effects on folate and vitamin A varied between studies. Improvements in WSH also reduced the risk of anemia in Bangladesh but did not provide added benefit over the nutrition-specific intervention. These trials were registered at clinicaltrials.gov as NCT01590095 (Bangladesh) and NCT01704105 (Kenya).}, journal={The American Journal of Clinical Nutrition}, author={Stewart, Christine P. and Dewey, Kathryn G. and Lin, Audrie and Pickering, Amy J. and Byrd, Kendra A. and Jannat, Kaniz and Ali, Shahjahan and Rao, Gouthami and Dentz, Holly N. and Kiprotich, Marion and et al.}, year={2019}, month={Jan} }
 @article{ercumen_benjamin-chung_arnold_lin_hubbard_stewart_rahman_parvez_unicomb_rahman_et al._2019, title={Effects of water, sanitation, handwashing and nutritional interventions on soil-transmitted helminth infections in young children: A cluster-randomized controlled trial in rural Bangladesh}, volume={13}, ISSN={["1935-2735"]}, DOI={10.1371/journal.pntd.0007323}, abstractNote={Soil transmitted helminths (STH) infect >1.5 billion people. Mass drug administration (MDA) effectively reduces infection; however, there is evidence for rapid reinfection and risk of potential drug resistance. We conducted a randomized controlled trial in Bangladesh (WASH Benefits, NCT01590095) to assess whether water, sanitation, hygiene and nutrition interventions, alone and combined, reduce STH in a setting with ongoing MDA.In 2012-2013, we randomized 720 clusters of 5551 pregnant women into water treatment, sanitation, handwashing, combined water+sanitation+handwashing (WSH), nutrition, nutrition+WSH (N+WSH) or control arms. In 2015-2016, we enrolled 7795 children, aged 2-12 years, of 4102 available women for STH follow-up and collected stool from 7187. We enumerated STH infections with Kato-Katz. We estimated intention-to-treat intervention effects on infection prevalence and intensity. Participants and field staff were not blinded; laboratory technicians and data analysts were blinded. Prevalence among controls was 36.8% for A. lumbricoides, 9.2% for hookworm and 7.5% for T. trichiura. Most infections were low-intensity. Compared to controls, the water intervention reduced hookworm by 31% (prevalence ratio [PR] = 0.69 (0.50,0.95), prevalence difference [PD] = -2.83 (-5.16,-0.50)) but did not affect other STH. Sanitation improvements reduced T. trichiura by 29% (PR = 0.71 (0.52,0.98), PD = -2.17 (-4.03,-0.38)), had a similar borderline effect on hookworm and no effect on A. lumbricoides. Handwashing and nutrition interventions did not reduce any STH. WSH and N+WSH reduced hookworm prevalence by 29-33% (WSH: PR = 0.71 (0.52,0.99), PD = -2.63 (-4.95,-0.31); N+WSH: PR = 0.67 (0.50,0.91), PD = -3.00 (-5.14,-0.85)) and marginally reduced A. lumbricoides. Effects on infection intensity were similar.In a low-intensity infection setting with MDA, we found modest but sustained hookworm reduction from water treatment and combined WSH interventions. Impacts were more pronounced on STH species with short vs. long-term environmental survival. Our findings suggest possible waterborne transmission for hookworm. Water treatment and sanitation improvements can augment MDA to interrupt STH transmission.NCT01590095.}, number={5}, journal={PLOS NEGLECTED TROPICAL DISEASES}, author={Ercumen, Ayse and Benjamin-Chung, Jade and Arnold, Benjamin F. and Lin, Audrie and Hubbard, Alan E. and Stewart, Christine and Rahman, Zahidur and Parvez, Sarker Masud and Unicomb, Leanne and Rahman, Mahbubur and et al.}, year={2019}, month={May} }
 @article{parvez_azad_pickering_kwong_arnold_rahman_rahman_alam_sen_islam_et al._2019, title={Microbiological contamination of young children's hands in rural Bangladesh: Associations with child age and observed hand cleanliness as proxy}, volume={14}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0222355}, abstractNote={Background Hands are a route of transmission for fecal-oral pathogens. This analysis aimed to assess associations between hand E. coli contamination and child age and determine if observed hand cleanliness can serve as a proxy for E. coli contamination on young children’s hands. Methods Trained field workers collected hand rinse samples from children aged 1–14 months in 584 households in rural Bangladesh and assessed the visual cleanliness of child hands (fingernails, finger pads and palms). Samples were analyzed using the IDEXX most probable number (MPN) methodto enumerate E. coli. We assessed if child age (immobile children aged 1–4 months vs. mobile children aged 5–14 months) is associated with log10 E. coli counts on hands using generalized estimating equations (GEE). We estimated the log10 difference in hand E. coli counts associated with the cleanliness of different hand parts using a multivariable GEE model.We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for dirty fingernails, fingerpads, palms and overall hands (the three observed parts combined) against binary E. coli presence on hands. Results E. coli was detected on 43% of child hands. Children in the mobile age range had 0.17 log10 MPN higher E. coli on hands than those in the immobile age range (Δlog10 = 0.17, 95% CI = 0.02, 0.32, p = 0.03). Children with visible dirt particles on finger pads had 0.46 log10 MPN higher E. coli on hands than those with clean finger pads (Δlog10 = 0.46, 95% CI = 0.05, 0.87, p = 0.03). Dirty fingernails indicated binary E. coli presence with 81% sensitivity and 26% specificity while dirty fingerpads and palms indicated E. coli presence with 29% sensitivity and 75–77% specificity. The PPV was 45–48% and NPV 59–65% for all three types of observations. Conclusion Hand contamination with E. coli was prevalent among young children in rural Bangladesh, with higher levels of contamination among mobile children. Studies should assess if strategies to remove animal feces from the courtyard, provide designated hygienic play spaces for children and deliver targeted messaging to mothers to wipe or wash children’s hands after contact with animals and animal feces reduce child hand contamination. Visible hand cleanliness was a poor predictor of E. coli presence on young children’s hands so other low-cost field measurements are needed to accurately detect fecal contamination on hands.}, number={9}, journal={PLOS ONE}, author={Parvez, Sarker Masud and Azad, Rashidul and Pickering, Amy J. and Kwong, Laura H. and Arnold, Benjamin F. and Rahman, Musarrat Jabeen and Rahman, Md Zahidur and Alam, Mahfuja and Sen, Debashis and Islam, Sharmin and et al.}, year={2019}, month={Sep} }
 @article{fuhrmeister_ercumen_pickering_jeanis_ahmed_brown_arnold_hubbard_alam_sen_et al._2019, title={Predictors of Enteric Pathogens in the Domestic Environment from Human and Animal Sources in Rural Bangladesh}, volume={53}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.8b07192}, abstractNote={Fecal indicator organisms are measured to indicate the presence of fecal pollution, yet the association between indicators and pathogens varies by context. The goal of this study was to empirically evaluate the relationships between indicator Escherichia coli, microbial source tracking markers, select enteric pathogen genes, and potential sources of enteric pathogens in 600 rural Bangladeshi households. We measured indicators and pathogen genes in stored drinking water, soil, and on mother and child hands. Additionally, survey and observational data on sanitation and domestic hygiene practices were collected. Log10 concentrations of indicator E. coli were positively associated with the prevalence of pathogenic E. coli genes in all sample types. Given the current need to rely on indicators to assess fecal contamination in the field, it is significant that in this study context indicator E. coli concentrations, measured by IDEXX Colilert-18, provided quantitative information on the presence of pathogenic E. coli in different sample types. There were no significant associations between the human fecal marker (HumM2) and human-specific pathogens in any environmental sample type. There was an increase in the prevalence of Giardia lamblia genes, any E. coli virulence gene, and the specific E. coli virulence genes stx1/2 with every log10 increase in the concentration of the animal fecal marker (BacCow) on mothers’ hands. Thus, domestic animals were important contributors to enteric pathogens in these households.}, number={17}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Fuhrmeister, Erica R. and Ercumen, Ayse and Pickering, Amy J. and Jeanis, Kaitlyn M. and Ahmed, Mahaa and Brown, Sara and Arnold, Benjamin F. and Hubbard, Alan E. and Alam, Mahfuja and Sen, Debashis and et al.}, year={2019}, month={Sep}, pages={10023–10033} }
 @article{naser_doza_rahman_ahmed_gazi_alam_karim_khan_uddin_mahmud_et al._2019, title={Sand barriers around latrine pits reduce fecal bacterial leaching into shallow groundwater: a randomized controlled trial in coastal Bangladesh}, volume={1}, ISSN={0013-936X}, url={https://doi.org/10.1021/acs.est.8b04950}, DOI={10.1021/acs.est.8b04950}, abstractNote={We evaluated the effectiveness of a sand barrier around latrine pits in reducing fecal indicator bacteria (FIB) leaching into shallow groundwater. We constructed 68 new offset single pit pour flush latrines in the Galachipa subdistrict of coastal Bangladesh. We randomly assigned 34 latrines to include a 50 cm thick sand barrier under and around the pit and 34 received no sand barrier. Four monitoring wells were constructed around each pit to collect water samples at baseline and subsequent nine follow-up visits over 24 months. Samples were tested using the IDEXX Colilert method to enumerate E. coli and thermotolerant coliforms most probable number (MPN). We determined the difference in mean log10MPN FIB counts/100 mL in monitoring well samples between latrines with and without a sand barrier using multilevel linear models and reported cluster robust standard error. The sand barrier latrine monitoring well samples had 0.38 mean log10MPN fewer E. coli (95% CI: 0.16, 0.59; p = 0.001) and 0.38 mean log10MPN fewer thermotolerant coliforms (95% CI: 0.14, 0.62; p = 0.002), compared to latrines without sand barriers, a reduction of 27% E. coli and 24% thermotolerant coliforms mean counts. A sand barrier can modestly reduce the risk presented by pit leaching.}, journal={Environmental Science & Technology}, author={Naser, Abu Mohd and Doza, Solaiman and Rahman, Mahbubur and Ahmed, Kazi Matin Uddin and Gazi, Mohammed Shahid and Alam, Gazi Raisul and Karim, Mohammed Rabiul and Khan, Golam Kibria and Uddin, Mohammed Nasir and Mahmud, Mohammed Ilias and et al.}, year={2019}, month={Jan} }
 @article{nery_pickering_abate_asmare_barrett_benjamin-chung_bundy_clasen_clements_colford_et al._2019, title={The role of water, sanitation and hygiene interventions in reducing soil-transmitted helminths: interpreting the evidence and identifying next steps}, volume={12}, ISBN={1756-3305}, DOI={10.1186/s13071-019-3532-6}, abstractNote={The transmission soil transmitted helminths (STH) occurs via ingestion of or contact with infective stages present in soil contaminated with human faeces. It follows therefore that efforts to reduce faecal contamination of the environment should help to reduce risk of parasite exposure and improvements in water, sanitation and hygiene (WASH) are seen as essential for the long-term, sustainable control of STH. However, the link between WASH and STH is not always supported by the available evidence from randomised controlled trials, which report mixed effects of WASH intervention on infection risk. This review critically summarises the available trial evidence and offers an interpretation of the observed heterogeneity in findings. The review also discusses the implications of findings for control programmes and highlights three main issues which merit further consideration: intervention design, exposure assessment, and intervention fidelity assessment.}, journal={PARASITES & VECTORS}, author={Nery, Susana Vaz and Pickering, Amy J. and Abate, Ebba and Asmare, Abraham and Barrett, Laura and Benjamin-Chung, Jade and Bundy, Donald A. P. and Clasen, Thomas and Clements, Archie C. A. and Colford, John M., Jr. and et al.}, year={2019} }
 @article{benjamin-chung_amin_ercumen_arnold_hubbard_unicomb_rahman_luby_colford_2018, title={A Randomized Controlled Trial to Measure Spillover Effects of a Combined Water, Sanitation, and Handwashing Intervention in Rural Bangladesh}, volume={3}, ISSN={1476-6256}, DOI={10.1093/aje/kwy046}, abstractNote={Abstract Water, sanitation, and handwashing interventions may confer spillover effects on intervention recipients’ neighbors by interrupting pathogen transmission. We measured geographically local spillovers in the Water Quality, Sanitation, and Handwashing (WASH) Benefits Study, a cluster-randomized trial in rural Bangladesh, by comparing outcomes among neighbors of intervention versus those of control participants. Geographically defined clusters were randomly allocated to a compound-level intervention (i.e., chlorinated drinking water, upgraded sanitation, and handwashing promotion) or control arm. From January 2015 to August 2015, in 180 clusters, we enrolled 1,799 neighboring children who were age matched to trial participants who would have been eligible for the study had they been conceived slightly earlier or later. After 28 months of intervention, we quantified fecal indicator bacteria in toy rinse and drinking water samples and measured soil-transmitted helminth infections and caregiver-reported diarrhea and respiratory illness. Neighbors’ characteristics were balanced across arms. Detectable Escherichia coli prevalence in tubewell samples was lower for intervention participants’ neighbors than control participants’ (prevalence ratio = 0.83; 95% confidence interval: 0.73, 0.95). Fecal indicator bacteria prevalence did not differ between arms for other environmental samples. Prevalence was similar in neighbors of intervention participants versus those of control participants for soil-transmitted helminth infection, diarrhea, and respiratory illness. A compound-level water, sanitation, and handwashing intervention reduced neighbors’ tubewell water contamination but did not affect neighboring children’s health.}, journal={American Journal of Epidemiology}, author={Benjamin-Chung, Jade and Amin, Nuhu and Ercumen, Ayse and Arnold, Benjamin F. and Hubbard, Alan E. and Unicomb, Leanne and Rahman, Mahbubur and Luby, Stephen P. and Colford, John M.}, year={2018}, month={Mar} }
 @article{ercumen_pickering_kwong_mertens_arnold_benjamin-chung_hubbard_alam_sen_islam_et al._2018, title={Do Sanitation Improvements Reduce Fecal Contamination of Water, Hands, Food, Soil, and Flies? Evidence from a Cluster-Randomized Controlled Trial in Rural Bangladesh}, volume={52}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.8b02988}, abstractNote={Sanitation improvements have had limited effectiveness in reducing the spread of fecal pathogens into the environment. We conducted environmental measurements within a randomized controlled trial in Bangladesh that implemented individual and combined water treatment, sanitation, handwashing (WSH) and nutrition interventions (WASH Benefits, NCT01590095). Following approximately 4 months of intervention, we enrolled households in the trial’s control, sanitation and combined WSH arms to assess whether sanitation improvements, alone and coupled with water treatment and handwashing, reduce fecal contamination in the domestic environment. We quantified fecal indicator bacteria in samples of drinking and ambient waters, child hands, food given to young children, courtyard soil and flies. In the WSH arm, Escherichia coli prevalence in stored drinking water was reduced by 62% (prevalence ratio = 0.38 (0.32, 0.44)) and E. coli concentration by 1-log (Δlog10 = −0.88 (−1.01, −0.75)). The interventions did not reduce E. coli along other sampled pathways. Ambient contamination remained high among intervention households. Potential reasons include noncommunity-level sanitation coverage, child open defecation, animal fecal sources, or naturalized E. coli in the environment. Future studies should explore potential threshold effects of different levels of community sanitation coverage on environmental contamination.}, number={21}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Ercumen, Ayse and Pickering, Amy J. and Kwong, Laura H. and Mertens, Andrew and Arnold, Benjamin F. and Benjamin-Chung, Jade and Hubbard, Alan E. and Alam, Mahfuja and Sen, Debashis and Islam, Sharmin and et al.}, year={2018}, month={Nov}, pages={12089–12097} }
 @article{naser_higgins_arman_ercumen_ashraf_das_rahman_luby_unicomb_2018, title={Effect of Groundwater Iron on Residual Chlorine in Water Treated with Sodium Dichloroisocyanurate Tablets in Rural Bangladesh}, volume={98}, ISSN={1476-1645}, DOI={10.4269/ajtmh.16-0954}, abstractNote={Abstract. We assessed the ability of sodium dichloroisocyanurate (NaDCC) to provide adequate chlorine residual when used to treat groundwater with variable iron concentration. We randomly selected 654 tube wells from nine subdistricts in central Bangladesh to measure groundwater iron concentration and corresponding residual-free chlorine after treating 10 L of groundwater with a 33-mg-NaDCC tablet. We assessed geographical variations of iron concentration using the Kruskal–Wallis test and examined the relationships between the iron concentrations and chlorine residual by quantile regression. We also assessed whether user-reported iron taste in water and staining of storage vessels can capture the presence of iron greater than 3 mg/L (the World Health Organization threshold). The median iron concentration among measured wells was 0.91 (interquartile range [IQR]: 0.36–2.01) mg/L and free residual chlorine was 1.3 (IQR: 0.6–1.7) mg/L. The groundwater iron content varied even within small geographical regions. The median free residual chlorine decreased by 0.29 mg/L (95% confidence interval: 0.27, 0.33, P < 0.001) for every 1 mg/L increase in iron concentration. Owner-reported iron staining of the storage vessel had a sensitivity of 92%, specificity of 75%, positive predictive value of 41%, and negative predictive value of 98% for detecting > 3 mg/L iron in water. Similar findings were observed for user-reported iron taste in water. Our findings reconfirm that chlorination of groundwater that contains iron may result in low-level or no residual. User reports of no iron taste or no staining of storage containers can be used to identify low-iron tube wells suitable for chlorination. Furthermore, research is needed to develop a color-graded visual scale for iron staining that corresponds to different iron concentrations in water.}, number={4}, journal={The American Journal of Tropical Medicine and Hygiene}, author={Naser, Abu Mohd and Higgins, Eilidh M. and Arman, Shaila and Ercumen, Ayse and Ashraf, Sania and Das, Kishor K. and Rahman, Mahbubur and Luby, Stephen P. and Unicomb, Leanne}, year={2018}, month={Apr}, pages={977–983} }
 @article{ercumen_mertens_arnold_benjamin-chung_hubbard_ahmed_kabir_khalil_kumar_rahman_et al._2018, title={Effects of Single and Combined Water, Sanitation and Handwashing Interventions on Fecal Contamination in the Domestic Environment: A Cluster-Randomized Controlled Trial in Rural Bangladesh}, volume={52}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.8b05153}, abstractNote={Water, sanitation, and hygiene interventions have varying effectiveness in reducing fecal contamination in the domestic environment; delivering them in combination could yield synergies. We conducted environmental assessments within a randomized controlled trial in Bangladesh that implemented single and combined water treatment, sanitation, handwashing (WSH) and nutrition interventions (WASH Benefits, NCT01590095). After one and two years of intervention, we quantified fecal indicator bacteria in samples of drinking water (from source or storage), child hands, children’s food and sentinel objects. In households receiving single water treatment interventions, Escherichia coli prevalence in stored drinking water was reduced by 50% and concentration by 1-log. E. coli prevalence in food was reduced by 30% and concentration by 0.5-log in households receiving single water treatment and handwashing interventions. Combined WSH did not reduce fecal contamination more effectively than its components. Interventions did not reduce E. coli in groundwater, on child hands and on objects. These findings suggest that WSH improvements reduced contamination along the direct transmission pathways of stored water and food but not along indirect upstream pathways. Our findings support implementing water treatment and handwashing to reduce fecal exposure through water and food but provide no evidence that combining interventions further reduces exposure.}, number={21}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Ercumen, Ayse and Mertens, Andrew and Arnold, Benjamin F. and Benjamin-Chung, Jade and Hubbard, Alan E. and Ahmed, Mir Alvee and Kabir, Mir Himayet and Khalil, Md. Masudur Rahman and Kumar, Ashish and Rahman, Md. Sajjadur and et al.}, year={2018}, month={Nov}, pages={12078–12088} }
 @article{lin_ercumen_benjamin-chung_arnold_das_haque_ashraf_parvez_unicomb_rahman_et al._2018, title={Effects of Water, Sanitation, Handwashing, and Nutritional Interventions on Child Enteric Protozoan Infections in Rural Bangladesh: A Cluster-Randomized Controlled Trial}, volume={67}, ISSN={1058-4838}, url={https://academic.oup.com/cid/article/67/10/1515/4969830}, DOI={10.1093/cid/ciy320}, abstractNote={The trial found that individual handwashing and sanitation interventions significantly reduced childhood Giardia infections. Combined interventions provided no additional benefit. To reduce Giardia infection, individual interventions may be more feasible and cost-effective than combined interventions in similar rural, low-income settings.}, number={10}, journal={Clinical Infectious Diseases}, author={Lin, Audrie and Ercumen, Ayse and Benjamin-Chung, Jade and Arnold, Benjamin F. and Das, Shimul and Haque, Rashidul and Ashraf, Sania and Parvez, Sarker M. and Unicomb, Leanne and Rahman, Mahbubur and et al.}, year={2018}, month={Oct}, pages={1515–1522} }
 @article{luby_rahman_arnold_unicomb_ashraf_winch_stewart_begum_hussain_benjamin-chung_et al._2018, title={Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Bangladesh: a cluster randomised controlled trial}, volume={6}, ISSN={2214-109X}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5809718/}, DOI={10.1016/S2214-109X(17)30490-4}, abstractNote={<h2>Summary</h2><h3>Background</h3> Diarrhoea and growth faltering in early childhood are associated with subsequent adverse outcomes. We aimed to assess whether water quality, sanitation, and handwashing interventions alone or combined with nutrition interventions reduced diarrhoea or growth faltering. <h3>Methods</h3> The WASH Benefits Bangladesh cluster-randomised trial enrolled pregnant women from villages in rural Bangladesh and evaluated outcomes at 1-year and 2-years' follow-up. Pregnant women in geographically adjacent clusters were block-randomised to one of seven clusters: chlorinated drinking water (water); upgraded sanitation (sanitation); promotion of handwashing with soap (handwashing); combined water, sanitation, and handwashing; counselling on appropriate child nutrition plus lipid-based nutrient supplements (nutrition); combined water, sanitation, handwashing, and nutrition; and control (data collection only). Primary outcomes were caregiver-reported diarrhoea in the past 7 days among children who were in utero or younger than 3 years at enrolment and length-for-age <i>Z</i> score among children born to enrolled pregnant women. Masking was not possible for data collection, but analyses were masked. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, number NCC01590095. <h3>Findings</h3> Between May 31, 2012, and July 7, 2013, 5551 pregnant women in 720 clusters were randomly allocated to one of seven groups. 1382 women were assigned to the control group; 698 to water; 696 to sanitation; 688 to handwashing; 702 to water, sanitation, and handwashing; 699 to nutrition; and 686 to water, sanitation, handwashing, and nutrition. 331 (6%) women were lost to follow-up. Data on diarrhoea at year 1 or year 2 (combined) were available for 14 425 children (7331 in year 1, 7094 in year 2) and data on length-for-age <i>Z</i> score in year 2 were available for 4584 children (92% of living children were measured at year 2). All interventions had high adherence. Compared with a prevalence of 5·7% (200 of 3517 child weeks) in the control group, 7-day diarrhoea prevalence was lower among index children and children under 3 years at enrolment who received sanitation (61 [3·5%] of 1760; prevalence ratio 0·61, 95% CI 0·46–0·81), handwashing (62 [3·5%] of 1795; 0·60, 0·45–0·80), combined water, sanitation, and handwashing (74 [3·9%] of 1902; 0·69, 0·53–0·90), nutrition (62 [3·5%] of 1766; 0·64, 0·49–0·85), and combined water, sanitation, handwashing, and nutrition (66 [3·5%] of 1861; 0·62, 0·47–0·81); diarrhoea prevalence was not significantly lower in children receiving water treatment (90 [4·9%] of 1824; 0·89, 0·70–1·13). Compared with control (mean length-for-age <i>Z</i> score −1·79), children were taller by year 2 in the nutrition group (mean difference 0·25 [95% CI 0·15–0·36]) and in the combined water, sanitation, handwashing, and nutrition group (0·13 [0·02–0·24]). The individual water, sanitation, and handwashing groups, and combined water, sanitation, and handwashing group had no effect on linear growth. <h3>Interpretation</h3> Nutrient supplementation and counselling modestly improved linear growth, but there was no benefit to the integration of water, sanitation, and handwashing with nutrition. Adherence was high in all groups and diarrhoea prevalence was reduced in all intervention groups except water treatment. Combined water, sanitation, and handwashing interventions provided no additive benefit over single interventions. <h3>Funding</h3> Bill & Melinda Gates Foundation.}, number={3}, journal={The Lancet. Global Health}, author={Luby, Stephen P and Rahman, Mahbubur and Arnold, Benjamin F and Unicomb, Leanne and Ashraf, Sania and Winch, Peter J and Stewart, Christine P and Begum, Farzana and Hussain, Faruqe and Benjamin-Chung, Jade and et al.}, year={2018}, month={Jan}, pages={e302–e315} }
 @article{pickering_ercumen_arnold_kwong_parvez_alam_sen_islam_kullmann_chase_et al._2018, title={Fecal Indicator Bacteria along Multiple Environmental Transmission Pathways (Water, Hands, Food, Soil, Flies) and Subsequent Child Diarrhea in Rural Bangladesh}, volume={52}, ISSN={1520-5851}, DOI={10.1021/acs.est.8b00928}, abstractNote={Enteric pathogens can be transmitted through multiple environmental pathways, yet little is known about the relative contribution of each pathway to diarrhea risk among children. We aimed to identify fecal transmission pathways in the household environment associated with prospectively measured child diarrhea in rural Bangladesh. We measured the presence and levels of Escherichia coli in tube wells, stored drinking water, pond water, child hand rinses, courtyard soil, flies, and food in 1843 households. Gastrointestinal symptoms among children ages 0–60 months were recorded concurrently at the time of environmental sample collection and again a median of 6 days later. Incident diarrhea (3 or more loose stools in a 24-h period) was positively associated with the concentration of E. coli on child hands measured on the first visit (incidence rate ratio [IRR] = 1.23, 95% CI 1.06, 1.43 for a log10 increase), while other pathways were not associated. In cross-sectional analysis, there were no associations between concurrently measured environmental contamination and diarrhea. Our findings suggest higher levels of E. coli on child hands are strongly associated with subsequent diarrheal illness rates among children in rural Bangladesh.}, number={14}, journal={Environmental Science & Technology}, author={Pickering, Amy J. and Ercumen, Ayse and Arnold, Benjamin F. and Kwong, Laura H. and Parvez, Sarker Masud and Alam, Mahfuja and Sen, Debashis and Islam, Sharmin and Kullmann, Craig and Chase, Claire and et al.}, year={2018}, month={Jul}, pages={7928–7936} }
 @article{ray_billava_burt_colford_ercumen_jayaramu_kumpel_nayak_nelson_woelfle-erskine_2018, title={From Intermittent to Continuous Water Supply. A household-level evaluation of water system reforms in Hubli-Dharwad}, volume={53}, url={https://www.epw.in/journal/2018/49/review-urban-affairs/intermittent-continuous-water-supply.html}, number={49}, journal={Economic and Political Weekly}, author={Ray, I. and Billava, N. and Burt, Z. and Colford, J.M. and Ercumen, A. and Jayaramu, K.P. and Kumpel, E. and Nayak, N. and Nelson, K. and Woelfle-Erskine, C.}, year={2018}, month={Dec}, pages={7–8} }
 @article{burt_ercümen_billava_ray_2018, title={From intermittent to continuous service: Costs, benefits, equity and sustainability of water system reforms in Hubli-Dharwad, India}, volume={109}, ISSN={0305-750X}, url={http://www.sciencedirect.com/science/article/pii/S0305750X1830130X}, DOI={10.1016/j.worlddev.2018.04.011}, abstractNote={Urban service provision falls somewhere on the continuum of lower-cost, lower-quality, unreliable and intermittent to higher-cost, higher-quality, reliable and continuous. Piped water services in India are generally in the former category, but efforts are underway in some cities to shift to continuous supply. We use a matched-cohort research design to evaluate one such effort: an upgrade to continuous water service in a pilot zone of Hubli-Dharwad, India, while the rest of the city remained on intermittent services. We conducted a survey of ∼4000 households with four rounds of data collection over 15 months. We evaluated the household-level net benefits, the equity of their distribution, and the affordability of water access under continuous supply. We also evaluated the project at the system-level (household and utility), estimating the net present value of the upgrade and the feasibility of scale-up to the entire city. We found positive net benefits for households overall, but uneven distribution of these benefits across socio-economic strata. We also found that the costs of supply augmentation, a necessary step for scale-up, significantly reduced the project net present value. The potential for scale-up is thus unclear.}, journal={World Development}, author={Burt, Zachary and Ercümen, Ayşe and Billava, Narayana and Ray, Isha}, year={2018}, month={Sep}, pages={121–133} }
 @article{doza_jabeen rahman_islam_kwong_unicomb_ercumen_pickering_parvez_naser_ashraf_et al._2018, title={Prevalence and Association of Escherichia coli and Diarrheagenic Escherichia coli in Stored Foods for Young Children and Flies Caught in the Same Households in Rural Bangladesh}, volume={98}, ISSN={1476-1645}, DOI={10.4269/ajtmh.17-0408}, abstractNote={Abstract. Consumption of contaminated stored food can cause childhood diarrhea. Flies carry enteropathogens, although their contribution to food contamination remains unclear. We investigated the role of flies in contaminating stored food by collecting food and flies from the same households in rural Bangladesh. We selected 182 households with children ≤ 24 months old that had stored foods for later feeding at room temperature for ≥ 3 hours. We collected food samples and captured flies with fly tapes hung by the kitchen. We used the IDEXX Quanti-Tray System (Colilert-18 media; IDEXX Laboratories, Inc., Westbrook, ME) to enumerate Escherichia coli with the most probable number (MPN) method. Escherichia coli–positive IDEXX wells were analyzed by polymerase chain reaction for pathogenic E. coli genes (eae, ial, bfp, ipaH, st, lt, aat, aaiC, stx1, and stx2). Escherichia coli was detected in 61% (111/182) of food samples, with a mean of 1.1 log10 MPN/dry g. Fifteen samples (8%) contained pathogenic E. coli; seven (4%) had enteropathogenic E. coli (EPEC) genes (eae and/or bfp); and 10 (5%) had enteroaggregative E. coli genes (aat and/or aaiC). Of flies captured in 68 (37%) households, E. coli was detected in 41 (60%, mean 2.9 log10 MPN/fly), and one fly (1%) had an EPEC gene (eae). For paired fly-food samples, each log10 MPN E. coli increase in flies was associated with a 0.31 log10 MPN E. coli increase in stored food (95% confidence interval: 0.07, 0.55). In rural Bangladesh, flies possibly a likely route for fecal contamination of stored food. Controlling fly populations may reduce contamination of food stored for young children.}, number={4}, journal={The American Journal of Tropical Medicine and Hygiene}, author={Doza, Solaiman and Jabeen Rahman, Musarrat and Islam, Mohammad Aminul and Kwong, Laura H. and Unicomb, Leanne and Ercumen, Ayse and Pickering, Amy J. and Parvez, Sarker Masud and Naser, Abu Mohd and Ashraf, Sania and et al.}, year={2018}, month={Apr}, pages={1031–1038} }
 @article{islam_ercumen_ashraf_rahman_shoab_luby_unicomb_2018, title={Unsafe disposal of feces of children <3 years among households with latrine access in rural Bangladesh: Association with household characteristics, fly presence and child diarrhea}, volume={13}, ISSN={1932-6203}, DOI={10.1371/journal.pone.0195218}, abstractNote={Background Young children frequently defecate in the living environment in low-income countries. Unsafe child feces disposal has been associated with risk of diarrhea. Additionally, reported practices can underestimate socially undesirable unhygienic behaviors. This analysis aimed to assess (1) the sensitivity of reported child feces disposal practices as an indicator for observed presence of human feces in the domestic environment, (2) household characteristics associated with reported unsafe feces disposal and (3) whether unsafe feces disposal is associated with fly presence and diarrhea among children <3 years. Methods We recorded caregiver-reported feces disposal practices for children <3 years; unsafe disposal was defined as feces put/rinsed into a drain, ditch, bush or garbage heap or left on the ground and safe disposal as feces put/rinsed into latrine or specific pit or buried. We conducted spot checks for human feces, counted flies in the compound and recorded caregiver-reported child diarrhea prevalence among 803 rural Bangladeshi households. We assessed associations using generalized estimating equations (GEE) and generalized linear models (GLM) with robust standard errors. Results Unsafe disposal of child feces was reported by 80% of households. Reported disposal practices had high sensitivity (91%) but low positive predictive value (15%) as an indicator of observed feces in the compound. Unsafe disposal was more common among households that reported daily adult open defecation (PR: 1.13, 1.02–1.24) and had children defecating in a nappy or on the ground versus in a potty (PR: 2.92, 1.98–4.32), and less common in households where adults reported always defecating in latrines (PR: 0.91, 0.84–0.98). The presence of observed human feces was similarly associated with these household characteristics. Reported unsafe feces disposal or observed human feces were not associated with fly detection or child diarrhea. Conclusion Despite access to on-site sanitation, unsafe child feces disposal was reported by the majority of households. However, this practices was not associated with diarrhea; suggesting that child feces may not be the most important fecal exposure. Before resources are invested to improve child feces management practices, studies should explore whether these contribute meaningfully to risk of enteric disease.}, number={4}, journal={PloS One}, author={Islam, Mahfuza and Ercumen, Ayse and Ashraf, Sania and Rahman, Mahbubur and Shoab, Abul K. and Luby, Stephen P. and Unicomb, Leanne}, year={2018}, pages={e0195218} }
 @article{arnold_schiff_ercumen_benjamin-chung_steele_griffith_steinberg_smith_mcgee_wilson_et al._2017, title={Acute Illness Among Surfers After Exposure to Seawater in Dry- and Wet-Weather Conditions}, volume={186}, url={http://dx.doi.org/10.1093/aje/kwx019}, DOI={10.1093/aje/kwx019}, abstractNote={Abstract Rainstorms increase levels of fecal indicator bacteria in urban coastal waters, but it is unknown whether exposure to seawater after rainstorms increases rates of acute illness. Our objective was to provide the first estimates of rates of acute illness after seawater exposure during both dry- and wet-weather periods and to determine the relationship between levels of indicator bacteria and illness among surfers, a population with a high potential for exposure after rain. We enrolled 654 surfers in San Diego, California, and followed them longitudinally during the 2013–2014 and 2014–2015 winters (33,377 days of observation, 10,081 surf sessions). We measured daily surf activities and illness symptoms (gastrointestinal illness, sinus infections, ear infections, infected wounds). Compared with no exposure, exposure to seawater during dry weather increased incidence rates of all outcomes (e.g., for earache or infection, adjusted incidence rate ratio (IRR) = 1.86, 95% confidence interval (CI): 1.27, 2.71; for infected wounds, IRR = 3.04, 95% CI: 1.54, 5.98); exposure during wet weather further increased rates (e.g., for earache or infection, IRR = 3.28, 95% CI: 1.95, 5.51; for infected wounds, IRR = 4.96, 95% CI: 2.18, 11.29). Fecal indicator bacteria measured in seawater (Enterococcus species, fecal coliforms, total coliforms) were strongly associated with incident illness only during wet weather. Urban coastal seawater exposure increases the incidence rates of many acute illnesses among surfers, with higher incidence rates after rainstorms.}, number={7}, journal={American Journal of Epidemiology,}, publisher={Oxford University Press (OUP)}, author={Arnold, B.F. and Schiff, K.C. and Ercumen, A. and Benjamin-Chung, J. and Steele, J.A. and Griffith, J.E. and Steinberg, S.J. and Smith, P. and McGee, C.D. and Wilson, R. and et al.}, year={2017}, month={Oct}, pages={866–875} }
 @article{ercumen_pickering_kwong_arnold_parvez_alam_sen_islam_kullmann_chase_et al._2017, title={Animal Feces Contribute to Domestic Fecal Contamination: Evidence from E. coli Measured in Water, Hands, Food, Flies, and Soil in Bangladesh}, volume={51}, ISSN={0013-936X}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5541329/}, DOI={10.1021/acs.est.7b01710}, abstractNote={Fecal-oral pathogens are transmitted through complex, environmentally mediated pathways. Sanitation interventions that isolate human feces from the environment may reduce transmission but have shown limited impact on environmental contamination. We conducted a study in rural Bangladesh to (1) quantify domestic fecal contamination in settings with high on-site sanitation coverage; (2) determine how domestic animals affect fecal contamination; and (3) assess how each environmental pathway affects others. We collected water, hand rinse, food, soil, and fly samples from 608 households. We analyzed samples with IDEXX Quantitray for the most probable number (MPN) of E. coli. We detected E. coli in source water (25%), stored water (77%), child hands (43%), food (58%), flies (50%), ponds (97%), and soil (95%). Soil had >120 000 mean MPN E. coli per gram. In compounds with vs without animals, E. coli was higher by 0.54 log10 in soil, 0.40 log10 in stored water and 0.61 log10 in food (p < 0.05). E. coli in stored water and food increased with increasing E. coli in soil, ponds, source water and hands. We provide empirical evidence of fecal transmission in the domestic environment despite on-site sanitation. Animal feces contribute to fecal contamination, and fecal indicator bacteria do not strictly indicate human fecal contamination when animals are present.}, number={15}, journal={Environmental Science & Technology}, author={Ercumen, Ayse and Pickering, Amy J. and Kwong, Laura H. and Arnold, Benjamin F. and Parvez, Sarker Masud and Alam, Mahfuja and Sen, Debashis and Islam, Sharmin and Kullmann, Craig and Chase, Claire and et al.}, year={2017}, month={Aug}, pages={8725–8734} }
 @article{ercumen_naser_arnold_unicomb_colford_luby_2017, title={Can Sanitary Inspection Surveys Predict Risk of Microbiological Contamination of Groundwater Sources? Evidence from Shallow Tubewells in Rural Bangladesh}, volume={96}, ISSN={1476-1645}, DOI={10.4269/ajtmh.16-0489}, abstractNote={Accurately assessing the microbiological safety of water sources is essential to reduce waterborne fecal exposures and track progress toward global targets of safe water access. Sanitary inspections are a recommended tool to assess water safety. We collected 1,684 water samples from 902 shallow tubewells in rural Bangladesh and conducted sanitary surveys to assess whether sanitary risk scores could predict water quality, as measured by Escherichia coli. We detected E. coli in 41% of tubewells, mostly at low concentrations. Based on sanitary scores, 31% of wells were low risk, 45% medium risk, and 25% high or very high risk. Older wells had higher risk scores. Escherichia coli levels were higher in wells where the platform was cracked or broken (Δlog10 = 0.09, 0.00-0.18) or undercut by erosion (Δlog10 = 0.13, 0.01-0.24). However, the positive predictive value of these risk factors for E. coli presence was low (< 50%). Latrine presence within 10 m was not associated with water quality during the wet season but was associated with less frequent E. coli detection during the dry season (relative risk = 0.72, 0.59-0.88). Sanitary scores were not associated with E. coli presence or concentration. These findings indicate that observed characteristics of a tubewell, as measured by sanitary inspections in their current form, do not sufficiently characterize microbiological water quality, as measured by E. coli. Assessments of local groundwater and geological conditions and improved water quality indicators may reveal more clear relationships. Our findings also suggest that the dominant contamination route for shallow groundwater sources is short-circuiting at the wellhead rather than subsurface transport.}, number={3}, journal={The American Journal of Tropical Medicine and Hygiene}, author={Ercumen, Ayse and Naser, Abu Mohd and Arnold, Benjamin F. and Unicomb, Leanne and Colford, John M. and Luby, Stephen P.}, year={2017}, month={Mar}, pages={561–568} }
 @article{steinbaum_kwong_ercumen_negash_lovely_njenga_boehm_pickering_nelson_2017, title={Detecting and enumerating soil-transmitted helminth eggs in soil: New method development and results from field testing in Kenya and Bangladesh}, volume={11}, ISSN={1935-2735}, DOI={10.1371/journal.pntd.0005522}, abstractNote={Globally, about 1.5 billion people are infected with at least one species of soil-transmitted helminth (STH). Soil is a critical environmental reservoir of STH, yet there is no standard method for detecting STH eggs in soil. We developed a field method for enumerating STH eggs in soil and tested the method in Bangladesh and Kenya. The US Environmental Protection Agency (EPA) method for enumerating Ascaris eggs in biosolids was modified through a series of recovery efficiency experiments; we seeded soil samples with a known number of Ascaris suum eggs and assessed the effect of protocol modifications on egg recovery. We found the use of 1% 7X as a surfactant compared to 0.1% Tween 80 significantly improved recovery efficiency (two-sided t-test, t = 5.03, p = 0.007) while other protocol modifications—including different agitation and flotation methods—did not have a significant impact. Soil texture affected the egg recovery efficiency; sandy samples resulted in higher recovery compared to loamy samples processed using the same method (two-sided t-test, t = 2.56, p = 0.083). We documented a recovery efficiency of 73% for the final improved method using loamy soil in the lab. To field test the improved method, we processed soil samples from 100 households in Bangladesh and 100 households in Kenya from June to November 2015. The prevalence of any STH (Ascaris, Trichuris or hookworm) egg in soil was 78% in Bangladesh and 37% in Kenya. The median concentration of STH eggs in soil in positive samples was 0.59 eggs/g dry soil in Bangladesh and 0.15 eggs/g dry soil in Kenya. The prevalence of STH eggs in soil was significantly higher in Bangladesh than Kenya (chi-square, χ2 = 34.39, p < 0.001) as was the concentration (Mann-Whitney, z = 7.10, p < 0.001). This new method allows for detecting STH eggs in soil in low-resource settings and could be used for standardizing soil STH detection globally.}, number={4}, journal={PLoS neglected tropical diseases}, author={Steinbaum, Lauren and Kwong, Laura H. and Ercumen, Ayse and Negash, Makeda S. and Lovely, Amira J. and Njenga, Sammy M. and Boehm, Alexandria B. and Pickering, Amy J. and Nelson, Kara L.}, year={2017}, month={Apr}, pages={e0005522} }
 @article{islam_ercumen_naser_unicomb_rahman_arnold_colford, jr._luby_2017, title={Effectiveness of the Hydrogen Sulfide Test as a Water Quality Indicator for Diarrhea Risk in Rural Bangladesh}, volume={97}, ISSN={0002-9637}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5805062/}, DOI={10.4269/ajtmh.17-0387}, abstractNote={Abstract. Microbiological water quality is usually assessed by the identification of Escherichia coli (E. coli), a fecal indicator. The hydrogen sulfide (H2S) test is an inexpensive, easy-to-use, and portable alternative field-based water quality test. Our study evaluated the H2S test’s effectiveness as a water quality indicator for diarrhea risk. Field workers collected stored drinking water samples for H2S analysis and detection of E. coli by membrane filtration and measured caregiver-reported diarrhea among children < 5 years in the same households 1 month later. We assessed the association between the H2S test (incubated for 24 hours and 48 hours) and diarrhea prevalence, with 2-day and 7-day symptom recall periods (N = 1,348). We determined the sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of the H2S test compared with E. coli (N = 525). Controlling for potentially confounding covariates, H2S-positive water (at 24 or 48 hours) was not associated with 2-day diarrhea prevalence (24-hour prevalence ratio [PR] = 1.03, 95% confidence interval [CI]: 0.63–1.69; 48-hour PR = 0.89, 95% CI: 0.58–1.38) or 7-day diarrhea prevalence (24-hour PR = 1.17, 95% CI: 0.76–1.78; 48-hour PR = 1.21, 95% CI: 0.81–1.80). The sensitivity, PPV, and NPV of the H2S test was significantly higher when the H2S test was incubated for 48 versus 24 hours whereas specificity showed the opposite trend. H2S test sensitivity, PPV, and NPV increased with increasing E. coli levels, consistent with previous evidence that the H2S test is a useful water quality tool in high-contamination settings. However, our results suggest that the H2S test is not an effective indicator for waterborne diarrhea.}, number={6}, journal={The American Journal of Tropical Medicine and Hygiene}, author={Islam, Mahfuza and Ercumen, Ayse and Naser, Abu Mohd and Unicomb, Leanne and Rahman, Mahbubur and Arnold, Benjamin F. and Colford, Jr., John M. and Luby, Stephen P.}, year={2017}, month={Dec}, pages={1867–1871} }
 @article{parvez_kwong_rahman_ercumen_pickering_ghosh_rahman_das_luby_unicomb_et al._2017, title={Escherichia coli contamination of child complementary foods and association with domestic hygiene in rural Bangladesh}, volume={22}, ISSN={1365-3156}, DOI={10.1111/tmi.12849}, abstractNote={Abstract}, number={5}, journal={Tropical medicine & international health: TM & IH}, author={Parvez, Sarker Masud and Kwong, Laura and Rahman, Musarrat Jabeen and Ercumen, Ayse and Pickering, Amy J. and Ghosh, Probir K. and Rahman, Md Zahidur and Das, Kishor Kumar and Luby, Stephen P. and Unicomb, Leanne and et al.}, year={2017}, month={May}, pages={547–557} }
 @article{ercumen_arnold_naser_unicomb_colford_luby_2017, title={Potential sources of bias in the use of Escherichia coli to measure waterborne diarrhoea risk in low-income settings}, volume={22}, ISSN={1365-3156}, DOI={10.1111/tmi.12803}, abstractNote={Abstract}, number={1}, journal={Tropical medicine & international health: TM & IH}, author={Ercumen, Ayse and Arnold, Benjamin F. and Naser, Abu Mohd and Unicomb, Leanne and Colford, John M. and Luby, Stephen P.}, year={2017}, month={Jan}, pages={2–11} }
 @article{arnold_ercumen_benjamin-chung_colford_2016, title={Brief Report: Negative Controls to Detect Selection Bias and Measurement Bias in Epidemiologic Studies}, volume={27}, ISSN={1531-5487}, DOI={10.1097/EDE.0000000000000504}, abstractNote={Supplemental Digital Content is available in the text.}, number={5}, journal={Epidemiology (Cambridge, Mass.)}, author={Arnold, Benjamin F. and Ercumen, Ayse and Benjamin-Chung, Jade and Colford, John M.}, year={2016}, month={Sep}, pages={637–641} }
 @article{kwong_ercumen_pickering_unicomb_davis_luby_2016, title={Hand- and Object-Mouthing of Rural Bangladeshi Children 3-18 Months Old}, volume={13}, ISSN={1660-4601}, DOI={10.3390/ijerph13060563}, abstractNote={Children are exposed to environmental contaminants by placing contaminated hands or objects in their mouths. We quantified hand- and object-mouthing frequencies of Bangladeshi children and determined if they differ from those of U.S. children to evaluate the appropriateness of applying U.S. exposure models in other socio-cultural contexts. We conducted a five-hour structured observation of the mouthing behaviors of 148 rural Bangladeshi children aged 3–18 months. We modeled mouthing frequencies using 2-parameter Weibull distributions to compare the modeled medians with those of U.S. children. In Bangladesh the median frequency of hand-mouthing was 37.3 contacts/h for children 3–6 months old, 34.4 contacts/h for children 6–12 months old, and 29.7 contacts/h for children 12–18 months old. The median frequency of object-mouthing was 23.1 contacts/h for children 3–6 months old, 29.6 contacts/h for children 6–12 months old, and 15.2 contacts/h for children 12–18 months old. At all ages both hand- and object-mouthing frequencies were higher than those of U.S. children. Mouthing frequencies were not associated with child location (indoor/outdoor). Using hand- and object-mouthing exposure models from U.S. and other high-income countries might not accurately estimate children’s exposure to environmental contaminants via mouthing in low- and middle-income countries.}, number={6}, journal={International Journal of Environmental Research and Public Health}, author={Kwong, Laura H. and Ercumen, Ayse and Pickering, Amy J. and Unicomb, Leanne and Davis, Jennifer and Luby, Stephen P.}, year={2016}, month={Apr} }
 @article{arnold_ercumen_2016, title={Negative Control Outcomes: A Tool to Detect Bias in Randomized Trials}, volume={316}, ISSN={1538-3598}, DOI={10.1001/jama.2016.17700}, abstractNote={Investigators have several design, measurement, and analytic tools to detect and reduce bias in epidemiological studies. One such approach, “negative controls,” has been used on an ad hoc basis for decades. A formal approach has recently been suggested for its use to detect confounding, selection, and measurement bias in epidemiological studies.1,2 Negative controls in epidemiological studies are analogous to negative controls in laboratory experiments, in which investigators test for problems with the experimental method by leaving out an essential ingredient, inactivating the hypothesized active ingredient, or checking for an effect that would be impossible by the hypothesized mechanism.1 A placebo treatment group in a randomized trial is an example of a negative control exposure (leaving out an essential ingredient) that helps remove bias that can result from participant or practitioner knowledge of an individual’s treatment assignment—the placebo treatment is susceptible to the same bias structure as the actual treatment but is causally unrelated to the outcome of interest. Negative control outcomes are conceptually similar but are subtly different because, unlike exposures in a randomized trial, they are not under investigator control. The formal definition of a negative control outcome is one that shares the same potential sources of}, number={24}, journal={JAMA}, author={Arnold, Benjamin F. and Ercumen, Ayse}, year={2016}, month={Dec}, pages={2597–2598} }
 @article{boehm_wang_ercumen_shea_harris_shanks_kelty_ahmed_mahmud_arnold_et al._2016, title={Occurrence of Host-Associated Fecal Markers on Child Hands, Household Soil, and Drinking Water in Rural Bangladeshi Households}, volume={3}, ISSN={2328-8930 2328-8930}, url={https://doi.org/10.1021/acs.estlett.6b00382}, DOI={10.1021/acs.estlett.6b00382}, abstractNote={We evaluated whether provision and promotion of improved sanitation hardware (toilets and child feces management tools) reduced rotavirus and human fecal contamination of drinking water, child hands, and soil among rural Bangladeshi compounds enrolled in a cluster-randomized trial. We also measured host-associated genetic markers of ruminant and avian feces. We found evidence of widespread ruminant and avian fecal contamination in the compound environment; non-human fecal marker occurrence scaled with animal ownership. Strategies for controlling non- human fecal waste should be considered when designing interventions to reduce exposure to fecal contamination in low-income settings. Detection of a human- associated fecal marker and rotavirus was rare and unchanged by provision and promotion of improved sanitation to intervention compounds. The sanitation intervention reduced ruminant fecal contamination in drinking water and general (non-host specific) fecal contamination in soil but overall had limited effects on reducing fecal contamination in the household environment.}, number={11}, journal={Environmental Science & Technology Letters}, publisher={American Chemical Society (ACS)}, author={Boehm, Alexandria B. and Wang, Dan and Ercumen, Ayse and Shea, Meghan and Harris, Angela R. and Shanks, Orin C. and Kelty, Catherine and Ahmed, Alvee and Mahmud, Zahid Hayat and Arnold, Benjamin F. and et al.}, year={2016}, month={Nov}, pages={393–398} }
 @article{mellor_kumpel_ercumen_zimmerman_2016, title={Systems Approach to Climate, Water, and Diarrhea in Hubli-Dharwad, India}, volume={50}, ISSN={0013-936X}, url={https://doi.org/10.1021/acs.est.6b02092}, DOI={10.1021/acs.est.6b02092}, abstractNote={Anthropogenic climate change will likely increase diarrhea rates for communities with inadequate water, sanitation, or hygiene facilities including those with intermittent water supplies. Current approaches to study these impacts typically focus on the effect of temperature on all-cause diarrhea while excluding precipitation and diarrhea etiology while not providing actionable adaptation strategies. We develop a partially mechanistic, systems approach to estimate future diarrhea prevalence and design adaptation strategies. The model incorporates downscaled global climate models, water quality data, quantitative microbial risk assessment, and pathogen prevalence in an agent-based modeling framework incorporating precipitation and diarrhea etiology. It is informed using water quality and diarrhea data from Hubli-Dharwad, India-a city with an intermittent piped water supply exhibiting seasonal water quality variability vulnerable to climate change. We predict all-cause diarrhea prevalence to increase by 4.9% (Range: 1.5-9.0%) by 2011-2030, 11.9% (Range: 7.1-18.2%) by 2046-2065, and 18.2% (Range: 9.1-26.2%) by 2080-2099. Rainfall is an important modifying factor. Rotavirus prevalence is estimated to decline by 10.5% with Cryptosporidium and E. coli prevalence increasing by 9.9% and 6.3%, respectively, by 2080-2099 in this setting. These results suggest that ceramic water filters would be recommended as a climate adaptation strategy over chlorination. This work highlights the vulnerability of intermittent water supplies to climate change and the urgent need for improvements.}, number={23}, journal={Environmental Science & Technology}, author={Mellor, Jonathan and Kumpel, Emily and Ercumen, Ayse and Zimmerman, Julie}, year={2016}, month={Dec}, pages={13042–13051} }
 @article{ercumen_naser_unicomb_arnold_colford_luby_2015, title={Effects of source- versus household contamination of tubewell water on child diarrhea in rural Bangladesh: a randomized controlled trial}, volume={10}, ISSN={1932-6203}, DOI={10.1371/journal.pone.0121907}, abstractNote={Background Shallow tubewells are the primary drinking water source for most rural Bangladeshis. Fecal contamination has been detected in tubewells, at low concentrations at the source and at higher levels at the point of use. We conducted a randomized controlled trial to assess whether improving the microbiological quality of tubewell drinking water by household water treatment and safe storage would reduce diarrhea in children <2 years in rural Bangladesh. Methods We randomly assigned 1800 households with a child aged 6-18 months (index child) into one of three arms: chlorine plus safe storage, safe storage and control. We followed households with monthly visits for one year to promote the interventions, track their uptake, test participants’ source and stored water for fecal contamination, and record caregiver-reported child diarrhea prevalence (primary outcome). To assess reporting bias, we also collected data on health outcomes that are not expected to be impacted by our interventions. Findings Both interventions had high uptake. Safe storage, alone or combined with chlorination, reduced heavy contamination of stored water. Compared to controls, diarrhea in index children was reduced by 36% in the chlorine plus safe storage arm (prevalence ratio, PR = 0.64, 0.55-0.73) and 31% in the safe storage arm (PR = 0.69, 0.60-0.80), with no difference between the two intervention arms. One limitation of the study was the non-blinded design with self-reported outcomes. However, the prevalence of health outcomes not expected to be impacted by water interventions did not differ between study arms, suggesting minimal reporting bias. Conclusions Safe storage significantly improved drinking water quality at the point of use and reduced child diarrhea in rural Bangladesh. There was no added benefit from combining safe storage with chlorination. Efforts should be undertaken to implement and evaluate long-term efforts for safe water storage in Bangladesh. Trial Registration ClinicalTrials.gov NCT01350063}, number={3}, journal={PloS One}, author={Ercumen, Ayse and Naser, Abu Mohd and Unicomb, Leanne and Arnold, Benjamin F. and Colford, John M. and Luby, Stephen P.}, year={2015}, pages={e0121907} }
 @article{julian_islam_pickering_roy_fuhrmeister_ercumen_harris_bishai_schwab_2015, title={Genotypic and Phenotypic Characterization of Escherichia coli Isolates from Feces, Hands, and Soils in Rural Bangladesh via the Colilert Quanti-Tray System}, volume={81}, ISSN={0099-2240, 1098-5336}, url={https://aem.asm.org/content/81/5/1735}, DOI={10.1128/AEM.03214-14}, abstractNote={ABSTRACT}, number={5}, journal={Appl. Environ. Microbiol.}, publisher={American Society for Microbiology}, author={Julian, Timothy R. and Islam, M. Aminul and Pickering, Amy J. and Roy, Subarna and Fuhrmeister, Erica R. and Ercumen, Ayse and Harris, Angela and Bishai, Jason and Schwab, Kellogg J.}, editor={Elkins, C. A.Editor}, year={2015}, month={Mar}, pages={1735–1743} }
 @article{ercumen_arnold_kumpel_burt_ray_nelson_jr_2015, title={Upgrading a Piped Water Supply from Intermittent to Continuous Delivery and Association with Waterborne Illness: A Matched Cohort Study in Urban India}, volume={12}, ISSN={1549-1676}, url={https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1001892}, DOI={10.1371/journal.pmed.1001892}, abstractNote={Background Intermittent delivery of piped water can lead to waterborne illness through contamination in the pipelines or during household storage, use of unsafe water sources during intermittencies, and limited water availability for hygiene. We assessed the association between continuous versus intermittent water supply and waterborne diseases, child mortality, and weight for age in Hubli-Dharwad, India. Methods and Findings We conducted a matched cohort study with multivariate matching to identify intermittent and continuous supply areas with comparable characteristics in Hubli-Dharwad. We followed 3,922 households in 16 neighborhoods with children <5 y old, with four longitudinal visits over 15 mo (Nov 2010–Feb 2012) to record caregiver-reported health outcomes (diarrhea, highly credible gastrointestinal illness, bloody diarrhea, typhoid fever, cholera, hepatitis, and deaths of children <2 y old) and, at the final visit, to measure weight for age for children <5 y old. We also collected caregiver-reported data on negative control outcomes (cough/cold and scrapes/bruises) to assess potential bias from residual confounding or differential measurement error. Continuous supply had no significant overall association with diarrhea (prevalence ratio [PR] = 0.93, 95% confidence interval [CI]: 0.83–1.04, p = 0.19), bloody diarrhea (PR = 0.78, 95% CI: 0.60–1.01, p = 0.06), or weight-for-age z-scores (Δz = 0.01, 95% CI: −0.07–0.09, p = 0.79) in children <5 y old. In prespecified subgroup analyses by socioeconomic status, children <5 y old in lower-income continuous supply households had 37% lower prevalence of bloody diarrhea (PR = 0.63, 95% CI: 0.46–0.87, p-value for interaction = 0.03) than lower-income intermittent supply households; in higher-income households, there was no significant association between continuous versus intermittent supply and child diarrheal illnesses. Continuous supply areas also had 42% fewer households with ≥1 reported case of typhoid fever (cumulative incidence ratio [CIR] = 0.58, 95% CI: 0.41–0.78, p = 0.001) than intermittent supply areas. There was no significant association with hepatitis, cholera, or mortality of children <2 y old; however, our results were indicative of lower mortality of children <2 y old (CIR = 0.51, 95% CI: 0.22–1.07, p = 0.10) in continuous supply areas. The major limitations of our study were the potential for unmeasured confounding given the observational design and measurement bias from differential reporting of health symptoms given the nonblinded treatment. However, there was no significant difference in the prevalence of the negative control outcomes between study groups that would suggest undetected confounding or measurement bias. Conclusions Continuous water supply had no significant overall association with diarrheal disease or ponderal growth in children <5 y old in Hubli-Dharwad; this might be due to point-of-use water contamination from continuing household storage and exposure to diarrheagenic pathogens through nonwaterborne routes. Continuous supply was associated with lower prevalence of dysentery in children in low-income households and lower typhoid fever incidence, suggesting that intermittently operated piped water systems are a significant transmission mechanism for Salmonella typhi and dysentery-causing pathogens in this urban population, despite centralized water treatment. Continuous supply was associated with reduced transmission, especially in the poorer higher-risk segments of the population.}, number={10}, journal={PLOS Medicine}, author={Ercumen, Ayse and Arnold, Benjamin F. and Kumpel, Emily and Burt, Zachary and Ray, Isha and Nelson, Kara and Jr, John M. Colford}, year={2015}, month={Oct}, pages={e1001892} }
 @article{gruber_ercumen_jr_2014, title={Coliform Bacteria as Indicators of Diarrheal Risk in Household Drinking Water: Systematic Review and Meta-Analysis}, volume={9}, ISSN={1932-6203}, url={https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0107429}, DOI={10.1371/journal.pone.0107429}, abstractNote={Background Current guidelines recommend the use of Escherichia coli (EC) or thermotolerant (“fecal”) coliforms (FC) as indicators of fecal contamination in drinking water. Despite their broad use as measures of water quality, there remains limited evidence for an association between EC or FC and diarrheal illness: a previous review found no evidence for a link between diarrhea and these indicators in household drinking water. Objectives We conducted a systematic review and meta-analysis to update the results of the previous review with newly available evidence, to explore differences between EC and FC indicators, and to assess the quality of available evidence. Methods We searched major databases using broad terms for household water quality and diarrhea. We extracted study characteristics and relative risks (RR) from relevant studies. We pooled RRs using random effects models with inverse variance weighting, and used standard methods to evaluate heterogeneity and publication bias. Results We identified 20 relevant studies; 14 studies provided extractable results for meta-analysis. When combining all studies, we found no association between EC or FC and diarrhea (RR 1.26 [95% CI: 0.98, 1.63]). When analyzing EC and FC separately, we found evidence for an association between diarrhea and EC (RR: 1.54 [95% CI: 1.37, 1.74]) but not FC (RR: 1.07 [95% CI: 0.79, 1.45]). Across all studies, we identified several elements of study design and reporting (e.g., timing of outcome and exposure measurement, accounting for correlated outcomes) that could be improved upon in future studies that evaluate the association between drinking water contamination and health. Conclusions Our findings, based on a review of the published literature, suggest that these two coliform groups have different associations with diarrhea in household drinking water. Our results support the use of EC as a fecal indicator in household drinking water.}, number={9}, journal={PLOS ONE}, author={Gruber, Joshua S. and Ercumen, Ayse and Jr, John M. Colford}, year={2014}, month={Sep}, pages={e107429} }
 @article{ercumen_gruber_colford_2014, title={Water distribution system deficiencies and the risk of gastrointestinal illness: A systematic review and meta-analysis}, volume={122}, url={http://dx.doi.org/10.1289/ehp.1306912}, DOI={10.1289/ehp.1306912}, abstractNote={Background: Water distribution systems are vulnerable to performance deficiencies that can cause (re)contamination of treated water and plausibly lead to increased risk of gastrointestinal illness (GII) in consumers. Objectives: It is well established that large system disruptions in piped water networks can cause GII outbreaks. We hypothesized that routine network problems can also contribute to background levels of waterborne illness and conducted a systematic review and meta-analysis to assess the impact of distribution system deficiencies on endemic GII. Methods: We reviewed published studies that compared direct tap water consumption to consumption of tap water re-treated at the point of use (POU) and studies of specific system deficiencies such as breach of physical or hydraulic pipe integrity and lack of disinfectant residual. Results: In settings with network malfunction, consumers of tap water versus POU-treated water had increased GII [incidence density ratio (IDR) = 1.34; 95% CI: 1.00, 1.79]. The subset of nonblinded studies showed a significant association between GII and tap water versus POU-treated water consumption (IDR = 1.52; 95% CI: 1.05, 2.20), but there was no association based on studies that blinded participants to their POU water treatment status (IDR = 0.98; 95% CI: 0.90, 1.08). Among studies focusing on specific network deficiencies, GII was associated with temporary water outages (relative risk = 3.26; 95% CI: 1.48, 7.19) as well as chronic outages in intermittently operated distribution systems (odds ratio = 1.61; 95% CI: 1.26, 2.07). Conclusions: Tap water consumption is associated with GII in malfunctioning distribution networks. System deficiencies such as water outages also are associated with increased GII, suggesting a potential health risk for consumers served by piped water networks. Citation: Ercumen A, Gruber JS, Colford JM Jr. 2014. Water distribution system deficiencies and gastrointestinal illness: a systematic review and meta-analysis. Environ Health Perspect 122:651–660; http://dx.doi.org/10.1289/ehp.1306912}, number={7}, journal={Environ Health Perspect}, publisher={Environmental Health Perspectives}, author={Ercumen, A. and Gruber, J.S. and Colford, J.M.}, year={2014}, pages={651–660} }
 @article{smith_yunus_khan_ercumen_yuan_smith_liaw_balmes_von ehrenstein_raqib_et al._2013, title={Chronic respiratory symptoms in children following in utero and early life exposure to arsenic in drinking water in Bangladesh}, volume={42}, ISSN={1464-3685}, DOI={10.1093/ije/dyt120}, abstractNote={BACKGROUND
Arsenic exposure via drinking water increases the risk of chronic respiratory disease in adults. However, information on pulmonary health effects in children after early life exposure is limited.


METHODS
This population-based cohort study set in rural Matlab, Bangladesh, assessed lung function and respiratory symptoms of 650 children aged 7-17 years. Children with in utero and early life arsenic exposure were compared with children exposed to less than 10 µg/l in utero and throughout childhood. Because most children drank the same water as their mother had drunk during pregnancy, we could not assess only in utero or only childhood exposure.


RESULTS
Children exposed in utero to more than 500 µg/l of arsenic were more than eight times more likely to report wheezing when not having a cold [odds ratio (OR) = 8.41, 95% confidence interval (CI): 1.66-42.6, P < 0.01] and more than three times more likely to report shortness of breath when walking on level ground (OR = 3.86, 95% CI: 1.09-13.7, P = 0.02) and when walking fast or climbing (OR = 3.19, 95% CI: 1.22-8.32, P < 0.01]. However, there was little evidence of reduced lung function in either exposure category.


CONCLUSIONS
Children with high in utero and early life arsenic exposure had marked increases in several chronic respiratory symptoms, which could be due to in utero exposure or to early life exposure, or to both. Our findings suggest that arsenic in water has early pulmonary effects and that respiratory symptoms are a better marker of early life arsenic toxicity than changes in lung function measured by spirometry.}, number={4}, journal={International Journal of Epidemiology}, author={Smith, Allan H. and Yunus, Mohammad and Khan, Al Fazal and Ercumen, Ayse and Yuan, Yan and Smith, Meera Hira and Liaw, Jane and Balmes, John and Ehrenstein, Ondine von and Raqib, Rubhana and et al.}, year={2013}, month={Aug}, pages={1077–1086} }
 @article{ercumen_kumpel_silverman_burt_2009, title={A Volunteer-Led Effort Linking Research to Development Practice to Promote Safe Water and Hygiene in Slums in India}, volume={1}, url={https://www.ingentaconnect.com/contentone/wef/wefproc/2009/00002009/00000001/art00049}, DOI={10.2175/193864709793847708}, journal={Proceedings of the Water Environment Federation}, author={Ercumen, Ayse and Kumpel, Emily and Silverman, Andrea and Burt, Zachary}, year={2009}, pages={523–539} }
 @article{smith_ercumen_yuan_steinmaus_2009, title={Increased lung cancer risks are similar whether arsenic is ingested or inhaled}, volume={19}, ISSN={1559-064X}, DOI={10.1038/jes.2008.73}, abstractNote={In 1980, the International Agency for Research on Cancer (IARC) determined there was sufficient evidence to support that inorganic arsenic was a human lung carcinogen based on studies involving exposure through inhalation. In 2004, IARC listed arsenic in drinking water as a cause of lung cancer, making arsenic the first substance established to cause human cancer through two unrelated pathways of exposure. It may initially seem counterintuitive that arsenic in drinking water would cause human lung cancer, and even if it did, one might expect risks to be orders of magnitude lower than those from direct inhalation into the lungs. In this paper, we consider lung cancer dose-response relationships for inhalation and ingestion of arsenic by focusing on two key studies, a cohort mortality study in the United States involving Tacoma smelter workers inhaling arsenic, and a lung cancer case-control study involving ingestion of arsenic in drinking water in northern Chile. When exposure was assessed based on the absorbed dose identified by concentrations of arsenic in urine, there was very little difference in the dose-response findings for lung cancer relative risks between inhalation and ingestion. The lung cancer mortality rate ratio estimate was 8.0 (95% CI 3.2-16.5, P<0.001) for an average urine concentration of 1179 microg/l after inhalation, and the odds ratio estimate of the lung cancer incidence rate ratio was 7.1 (95% CI 3.4-14.8, P<0.001) for an estimated average urine concentration of 825 microg/l following ingestion. The slopes of the linear dose-response relationships between excess relative risk (RR-1) for lung cancer and urinary arsenic concentration were similar for the two routes of exposure. We conclude that lung cancer risks probably depend on absorbed dose, and not on whether inorganic arsenic is ingested or inhaled.}, number={4}, journal={Journal of Exposure Science & Environmental Epidemiology}, author={Smith, Allan H. and Ercumen, Ayse and Yuan, Yan and Steinmaus, Craig M.}, year={2009}, month={May}, pages={343–348} }