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Nguyen AT, Grembi JA, Riviere M, Barratt Heitmann G, Hutson WD, Athni TS, Patil A, Ercumen A, Lin A, Crider Y, Mertens A, Unicomb L, Rahman M, Luby SP, Arnold BF, Benjamin-Chung J. Influence of Temperature and Precipitation on the Effectiveness of Water, Sanitation, and Handwashing Interventions against Childhood Diarrheal Disease in Rural Bangladesh: A Reanalysis of the WASH Benefits Bangladesh Trial. ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:47006. [PMID: 38602833 PMCID: PMC11008709 DOI: 10.1289/ehp13807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 03/08/2024] [Accepted: 03/13/2024] [Indexed: 04/13/2024]
Abstract
BACKGROUND Diarrheal disease is a leading cause of childhood morbidity and mortality globally. Household water, sanitation, and handwashing (WASH) interventions can reduce exposure to diarrhea-causing pathogens, but meteorological factors may impact their effectiveness. Information about effect heterogeneity under different weather conditions is critical to refining these targeted interventions. OBJECTIVES We aimed to determine whether temperature and precipitation modified the effect of low-cost, point-of-use WASH interventions on child diarrhea. METHODS We analyzed data from a trial in rural Bangladesh that compared child diarrhea prevalence between clusters (N = 720 ) that were randomized to different WASH interventions between 2012 and 2016 (NCT01590095). We matched temperature and precipitation measurements to diarrhea outcomes (N = 12,440 measurements, 6,921 children) by geographic coordinates and date. We estimated prevalence ratios (PRs) using generative additive models and targeted maximum likelihood estimation to assess the effectiveness of each WASH intervention under different weather conditions. RESULTS Generally, WASH interventions most effectively prevented diarrhea during monsoon season, particularly following weeks with heavy rain or high temperatures. The PR for diarrhea in the WASH interventions group compared with the control group was 0.49 (95% CI: 0.35, 0.68) after 1 d of heavy rainfall, with a less-protective effect [PR = 0.87 (95% CI: 0.60, 1.25)] when there were no days with heavy rainfall. Similarly, the PR for diarrhea in the WASH intervention group compared with the control group was 0.60 (95% CI: 0.48, 0.75) following above-median temperatures vs. 0.91 (95% CI: 0.61, 1.35) following below-median temperatures. The influence of precipitation and temperature varied by intervention type; for precipitation, the largest differences in effectiveness were for the sanitation and combined WASH interventions. DISCUSSION WASH intervention effectiveness was strongly influenced by precipitation and temperature, and nearly all protective effects were observed during the rainy season. Future implementation of these interventions should consider local environmental conditions to maximize effectiveness, including targeted efforts to maintain latrines and promote community adoption ahead of monsoon seasons. https://doi.org/10.1289/EHP13807.
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Affiliation(s)
- Anna T. Nguyen
- Department of Epidemiology and Population Health, Stanford University, Stanford, California, USA
| | - Jessica A. Grembi
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - Marie Riviere
- Department of Epidemiology and Population Health, Stanford University, Stanford, California, USA
| | | | - William D. Hutson
- Brown School, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Tejas S. Athni
- Department of Epidemiology and Population Health, Stanford University, Stanford, California, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Arusha Patil
- Department of Epidemiology and Population Health, Stanford University, Stanford, California, USA
| | - Ayse Ercumen
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, USA
| | - Audrie Lin
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California, USA
| | - Yoshika Crider
- King Center on Global Development, Stanford University, Stanford, California, USA
| | - Andrew Mertens
- Division of Epidemiology and Biostatistics, University of California, Berkeley, Berkeley, California, USA
| | - Leanne Unicomb
- Environmental Health and WASH, Health System and Population Studies Division, ICDDR,B, Dhaka, Bangladesh
| | - Mahbubur Rahman
- Environmental Health and WASH, Health System and Population Studies Division, ICDDR,B, Dhaka, Bangladesh
| | - Stephen P. Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - Benjamin F. Arnold
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, California, USA
| | - Jade Benjamin-Chung
- Department of Epidemiology and Population Health, Stanford University, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
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Contreras JD, Islam M, Mertens A, Pickering AJ, Arnold BF, Benjamin-Chung J, Hubbard AE, Rahman M, Unicomb L, Luby SP, Colford JM, Ercumen A. 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. J Epidemiol Glob Health 2024:10.1007/s44197-024-00210-y. [PMID: 38507184 DOI: 10.1007/s44197-024-00210-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/14/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND The WASH benefits Bangladesh trial multi-component sanitation intervention reduced diarrheal disease among children < 5 years. Intervention components included latrine upgrades, child feces management tools, and behavioral promotion. It remains unclear which components most impacted diarrhea. METHODS We conducted mediation analysis within a subset of households (n = 720) from the sanitation and control arms. Potential mediators were categorized into indicators of latrine quality, latrine use practices, and feces management practices. We estimated average causal mediation effects (ACME) as prevalence differences (PD), defined as the intervention's effect on diarrhea through its effect on the mediator. RESULTS The intervention improved all indicators compared to controls. We found significant mediation through multiple latrine use and feces management practice indicators. The strongest mediators during monsoon seasons were reduced open defecation among children aged < 3 and 3-8 years, and increased disposal of child feces into latrines. The strongest mediators during dry seasons were access to a flush/pour-flush latrine, reduced open defecation among children aged 3-8 years, and increased disposal of child feces into latrines. Individual mediation effects were small (PD = 0.5-2 percentage points) compared to the overall intervention effect but collectively describe significant mediation pathways. DISCUSSION The effect of the WASH Benefits Bangladesh sanitation intervention on diarrheal disease was mediated through improved child feces management and reduced child open defecation. Although the intervention significantly improved latrine quality, relatively high latrine quality at baseline may have limited benefits from additional improvements. Targeting safe child feces management may increase the health benefits of rural sanitation interventions.
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Affiliation(s)
- Jesse D Contreras
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, 48103, USA
| | - Mahfuza Islam
- Department of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Andrew Mertens
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Amy J Pickering
- Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA
| | - Benjamin F Arnold
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Jade Benjamin-Chung
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA
- Department of Epidemiology and Population Health, Stanford University, Palo Alto, CA, 94304, USA
| | - Alan E Hubbard
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Mahbubur Rahman
- Environmental Health and WASH, Health Systems and Population Studies Division, International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, 1212, Bangladesh
| | - Leanne Unicomb
- Environmental Health and WASH, Health Systems and Population Studies Division, International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, 1212, Bangladesh
| | - Stephen P Luby
- Woods Institute for the Environment, Stanford University, Stanford, CA, 94305, USA
| | - John M Colford
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Ayse Ercumen
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA.
- Jordan Hall Addition 2225, Raleigh, NC, 27606, USA.
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Ante-Testard PA, Rerolle F, Nguyen AT, Ashraf S, Parvez SM, Naser AM, Benmarhnia T, Rahman M, Luby SP, Benjamin-Chung J, Arnold BF. WASH interventions and child diarrhea at the interface of climate and socioeconomic position in Bangladesh. Nat Commun 2024; 15:1556. [PMID: 38378704 PMCID: PMC10879131 DOI: 10.1038/s41467-024-45624-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 01/30/2024] [Indexed: 02/22/2024] Open
Abstract
Many diarrhea-causing pathogens are climate-sensitive, and populations with the lowest socioeconomic position (SEP) are often most vulnerable to climate-related transmission. Household Water, Sanitation, and Handwashing (WASH) interventions constitute one potential effective strategy to reduce child diarrhea, especially among low-income households. Capitalizing on a cluster randomized trial population (360 clusters, 4941 children with 8440 measurements) in rural Bangladesh, one of the world's most climate-sensitive regions, we show that improved WASH substantially reduces diarrhea risk with largest benefits among children with lowest SEP and during the monsoon season. We extrapolated trial results to rural Bangladesh regions using high-resolution geospatial layers to identify areas most likely to benefit. Scaling up a similar intervention could prevent an estimated 734 (95% CI 385, 1085) cases per 1000 children per month during the seasonal monsoon, with marked regional heterogeneities. Here, we show how to extend large-scale trials to inform WASH strategies among climate-sensitive and low-income populations.
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Affiliation(s)
- Pearl Anne Ante-Testard
- Francis I. Proctor Foundation and Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA.
| | - Francois Rerolle
- Francis I. Proctor Foundation and Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
- Scripps Institution of Oceanography, University of California, San Diego, San Diego, CA, USA
| | - Anna T Nguyen
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA, USA
| | - Sania Ashraf
- Environmental Health and WASH, Health System and Population Studies Division, icddr,b, Dhaka, 1212, Bangladesh
| | - Sarker Masud Parvez
- Environmental Health and WASH, Health System and Population Studies Division, icddr,b, Dhaka, 1212, Bangladesh
- Child Health Research Centre, The University of Queensland, South Brisbane, QLD, Australia
| | - Abu Mohammed Naser
- Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, University of Memphis, Memphis, TN, USA
| | - Tarik Benmarhnia
- Scripps Institution of Oceanography, University of California, San Diego, San Diego, CA, USA
| | - Mahbubur Rahman
- Environmental Health and WASH, Health System and Population Studies Division, icddr,b, Dhaka, 1212, Bangladesh
| | - Stephen P Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | - Jade Benjamin-Chung
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA
| | - Benjamin F Arnold
- Francis I. Proctor Foundation and Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
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Kikuchi M. Influence of sanitation facilities on diarrhea prevalence among children aged below 5 years in flood-prone areas of Bangladesh: a multilevel analysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:97925-97935. [PMID: 37603245 PMCID: PMC10495509 DOI: 10.1007/s11356-023-29373-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 08/13/2023] [Indexed: 08/22/2023]
Abstract
Although the improvement of sanitation facilities has been a major contributor to improving public health, it is not guaranteed to prevent negative health outcomes. This is especially true in areas affected by severe natural disasters, such as flooding or extreme rainfall. Previous studies have examined the association between catastrophic natural disasters and negative health outcomes. However, studies on disaster-prone areas are limited. This study focused on the impact of flood risks and examined whether the improvement of sanitation facilities would be sufficient to suppress the prevalence of diarrhea in flood-prone areas. Two secondary datasets including geodata on flood-prone areas were used for the analysis: one each was obtained from the Bangladesh Demographic and Health Survey and Bangladesh Agricultural Research Council. Two models with categorizations of sanitation facilities based on containment type and excreta flow were applied for analysis. Results showed that the severe flood-prone areas and "diffused" type of sanitation, where the feces are diffused without any containment, had significant positive associations with diarrhea prevalence; however, the interaction between them was negative. Moderate flood-prone areas had a significant positive association with diarrhea prevalence; however, the interaction with unimproved sanitation, which includes containment without clear partition from feces, was significantly negative. These findings indicate that improved sanitation or containment type of sanitation may not positively contribute to the prevention of diarrhea in these severe- and moderate-flood prone areas. The urgent need for alternative sanitation technologies should be addressed in flood-prone regions.
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Affiliation(s)
- Michiko Kikuchi
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa City, Chiba Prefecture, 277-8561, Japan.
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Jefferson T, Dooley L, Ferroni E, Al-Ansary LA, van Driel ML, Bawazeer GA, Jones MA, Hoffmann TC, Clark J, Beller EM, Glasziou PP, Conly JM. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database Syst Rev 2023; 1:CD006207. [PMID: 36715243 PMCID: PMC9885521 DOI: 10.1002/14651858.cd006207.pub6] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Viral epidemics or pandemics of acute respiratory infections (ARIs) pose a global threat. Examples are influenza (H1N1) caused by the H1N1pdm09 virus in 2009, severe acute respiratory syndrome (SARS) in 2003, and coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 in 2019. Antiviral drugs and vaccines may be insufficient to prevent their spread. This is an update of a Cochrane Review last published in 2020. We include results from studies from the current COVID-19 pandemic. OBJECTIVES To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses. SEARCH METHODS We searched CENTRAL, PubMed, Embase, CINAHL, and two trials registers in October 2022, with backwards and forwards citation analysis on the new studies. SELECTION CRITERIA We included randomised controlled trials (RCTs) and cluster-RCTs investigating physical interventions (screening at entry ports, isolation, quarantine, physical distancing, personal protection, hand hygiene, face masks, glasses, and gargling) to prevent respiratory virus transmission. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. MAIN RESULTS We included 11 new RCTs and cluster-RCTs (610,872 participants) in this update, bringing the total number of RCTs to 78. Six of the new trials were conducted during the COVID-19 pandemic; two from Mexico, and one each from Denmark, Bangladesh, England, and Norway. We identified four ongoing studies, of which one is completed, but unreported, evaluating masks concurrent with the COVID-19 pandemic. Many studies were conducted during non-epidemic influenza periods. Several were conducted during the 2009 H1N1 influenza pandemic, and others in epidemic influenza seasons up to 2016. Therefore, many studies were conducted in the context of lower respiratory viral circulation and transmission compared to COVID-19. The included studies were conducted in heterogeneous settings, ranging from suburban schools to hospital wards in high-income countries; crowded inner city settings in low-income countries; and an immigrant neighbourhood in a high-income country. Adherence with interventions was low in many studies. The risk of bias for the RCTs and cluster-RCTs was mostly high or unclear. Medical/surgical masks compared to no masks We included 12 trials (10 cluster-RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and 10 in the community). Wearing masks in the community probably makes little or no difference to the outcome of influenza-like illness (ILI)/COVID-19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants; moderate-certainty evidence. Wearing masks in the community probably makes little or no difference to the outcome of laboratory-confirmed influenza/SARS-CoV-2 compared to not wearing masks (RR 1.01, 95% CI 0.72 to 1.42; 6 trials, 13,919 participants; moderate-certainty evidence). Harms were rarely measured and poorly reported (very low-certainty evidence). N95/P2 respirators compared to medical/surgical masks We pooled trials comparing N95/P2 respirators with medical/surgical masks (four in healthcare settings and one in a household setting). We are very uncertain on the effects of N95/P2 respirators compared with medical/surgical masks on the outcome of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; 3 trials, 7779 participants; very low-certainty evidence). N95/P2 respirators compared with medical/surgical masks may be effective for ILI (RR 0.82, 95% CI 0.66 to 1.03; 5 trials, 8407 participants; low-certainty evidence). Evidence is limited by imprecision and heterogeneity for these subjective outcomes. The use of a N95/P2 respirators compared to medical/surgical masks probably makes little or no difference for the objective and more precise outcome of laboratory-confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; 5 trials, 8407 participants; moderate-certainty evidence). Restricting pooling to healthcare workers made no difference to the overall findings. Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies (very low-certainty evidence). One previously reported ongoing RCT has now been published and observed that medical/surgical masks were non-inferior to N95 respirators in a large study of 1009 healthcare workers in four countries providing direct care to COVID-19 patients. Hand hygiene compared to control Nineteen trials compared hand hygiene interventions with controls with sufficient data to include in meta-analyses. Settings included schools, childcare centres and homes. Comparing hand hygiene interventions with controls (i.e. no intervention), there was a 14% relative reduction in the number of people with ARIs in the hand hygiene group (RR 0.86, 95% CI 0.81 to 0.90; 9 trials, 52,105 participants; moderate-certainty evidence), suggesting a probable benefit. In absolute terms this benefit would result in a reduction from 380 events per 1000 people to 327 per 1000 people (95% CI 308 to 342). When considering the more strictly defined outcomes of ILI and laboratory-confirmed influenza, the estimates of effect for ILI (RR 0.94, 95% CI 0.81 to 1.09; 11 trials, 34,503 participants; low-certainty evidence), and laboratory-confirmed influenza (RR 0.91, 95% CI 0.63 to 1.30; 8 trials, 8332 participants; low-certainty evidence), suggest the intervention made little or no difference. We pooled 19 trials (71, 210 participants) for the composite outcome of ARI or ILI or influenza, with each study only contributing once and the most comprehensive outcome reported. Pooled data showed that hand hygiene may be beneficial with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.83 to 0.94; low-certainty evidence), but with high heterogeneity. In absolute terms this benefit would result in a reduction from 200 events per 1000 people to 178 per 1000 people (95% CI 166 to 188). Few trials measured and reported harms (very low-certainty evidence). We found no RCTs on gowns and gloves, face shields, or screening at entry ports. AUTHORS' CONCLUSIONS The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions. There were additional RCTs during the pandemic related to physical interventions but a relative paucity given the importance of the question of masking and its relative effectiveness and the concomitant measures of mask adherence which would be highly relevant to the measurement of effectiveness, especially in the elderly and in young children. There is uncertainty about the effects of face masks. The low to moderate certainty of evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect. The pooled results of RCTs did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection. Hand hygiene is likely to modestly reduce the burden of respiratory illness, and although this effect was also present when ILI and laboratory-confirmed influenza were analysed separately, it was not found to be a significant difference for the latter two outcomes. Harms associated with physical interventions were under-investigated. There is a need for large, well-designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk of ARIs.
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Affiliation(s)
- Tom Jefferson
- Department for Continuing Education, University of Oxford, Oxford OX1 2JA, UK
| | - Liz Dooley
- Institute for Evidence-Based Healthcare, Bond University, Gold Coast, Australia
| | - Eliana Ferroni
- Epidemiological System of the Veneto Region, Regional Center for Epidemiology, Veneto Region, Padova, Italy
| | - Lubna A Al-Ansary
- Department of Family and Community Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mieke L van Driel
- General Practice Clinical Unit, Faculty of Medicine, The University of Queensland, Brisbane, Australia
- Department of Public Health and Primary Care, Ghent University, Ghent, Belgium
| | - Ghada A Bawazeer
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mark A Jones
- Institute for Evidence-Based Healthcare, Bond University, Gold Coast, Australia
| | - Tammy C Hoffmann
- Institute for Evidence-Based Healthcare, Bond University, Gold Coast, Australia
| | - Justin Clark
- Institute for Evidence-Based Healthcare, Bond University, Gold Coast, Australia
| | - Elaine M Beller
- Institute for Evidence-Based Healthcare, Bond University, Gold Coast, Australia
| | - Paul P Glasziou
- Institute for Evidence-Based Healthcare, Bond University, Gold Coast, Australia
| | - John M Conly
- Cumming School of Medicine, University of Calgary, Room AGW5, SSB, Foothills Medical Centre, Calgary, Canada
- O'Brien Institute for Public Health and Synder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Canada
- Calgary Zone, Alberta Health Services, Calgary, Canada
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6
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Contreras JD, Islam M, Mertens A, Pickering AJ, Kwong LH, Arnold BF, Benjamin-Chung J, Hubbard AE, Alam M, Sen D, Islam S, Rahman M, Unicomb L, Luby SP, Colford JM, Ercumen A. Influence of community-level sanitation coverage and population density on environmental fecal contamination and child health in a longitudinal cohort in rural Bangladesh. Int J Hyg Environ Health 2022; 245:114031. [PMID: 36058111 PMCID: PMC9489923 DOI: 10.1016/j.ijheh.2022.114031] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/15/2022] [Accepted: 08/24/2022] [Indexed: 11/28/2022]
Abstract
Background 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. Methods 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. Results 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. Conclusion 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.
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Affiliation(s)
- Jesse D Contreras
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, 27695, United States
| | - Mahfuza Islam
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, 1212, Bangladesh
| | - Andrew Mertens
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, California, 94720, United States
| | - Amy J Pickering
- Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, California, 94720, United States
| | - Laura H Kwong
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, California, 94720, United States
| | - Benjamin F Arnold
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, California, 94158, United States
| | - Jade Benjamin-Chung
- Department of Epidemiology and Population Health, Stanford University, Palo Alto, California, 94304, United States
| | - Alan E Hubbard
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, California, 94720, United States
| | - Mahfuja Alam
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, 1212, Bangladesh
| | - Debashis Sen
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, 1212, Bangladesh
| | - Sharmin Islam
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, 1212, Bangladesh
| | - Mahbubur Rahman
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, 1212, Bangladesh
| | - Leanne Unicomb
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, 1212, Bangladesh
| | - Stephen P Luby
- Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, 94305, United States
| | - John M Colford
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, California, 94720, United States
| | - Ayse Ercumen
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, 27695, United States.
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