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Legge H, Kazungo K, Muli S, Elson L, Mwongeli J, Halliday KE, Ochwal V, Oswald W, Dreibelbis R, Njomo D, Mwandawiro C, Fillinger U, Pullan R, Kepha S. Identifying Potential Determinants of Faecal Contamination on Domestic Floors in Three Settings in Rural Kenya: A Mixed Methods Analysis. ENVIRONMENTAL HEALTH INSIGHTS 2024; 18:11786302241246454. [PMID: 38737960 PMCID: PMC11088304 DOI: 10.1177/11786302241246454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 03/21/2024] [Indexed: 05/14/2024]
Abstract
Observational evidence suggests that household floors may be an important domain for the transmission of enteric and parasitic infections. However, little work has been done to investigate how household floors can become contaminated with human and animal faeces. This study uses a mixed methods approach to postulate the proximal and distal determinants of household floor contamination with faeces in groups of rural villages in 3 counties in Kenya (Bungoma, Kwale and Narok). Quantitative data was collected through a household census and analysed descriptively and using mixed effects logistic regression models. Qualitative data was collected through unstructured observations of daily routines and in-depth interviews. These data were analysed thematically with case memos produced for routine activities that were hypothesised to be determinants of floor contamination. Possible proximal determinants of floor contamination included; (1) animal contact with floors; (2) child faeces disposal, and; (3) floor cleaning routines. Distal determinants are suggested to be rooted in the socioeconomic, environmental, and cultural context in which households were located and included; (1) the type and number of animals owned by households; (2) presence/absence of dedicated shelters for housing animals at night, which impacted whether sleeping or cooking areas were exposed to animals; (3) Accessibility of inside spaces to poultry and other roaming animals; (4) ownership of an improved floor; (5) ability of animals to access neighbours compounds; (6) seasonal changes in weather. These results will be of use in identifying the contexts in which faecal contamination of domestic floors may be contributing towards transmission of enteric and parasitic infections and in designing effective interventions to prevent this exposure.
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Affiliation(s)
- Hugo Legge
- London School of Hygiene & Tropical Medicine, UK
| | - Karisa Kazungo
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Sharon Muli
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Lynne Elson
- KEMRI-Wellcome Trust, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, UK
| | - Jacinta Mwongeli
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | | | - Victoria Ochwal
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - William Oswald
- London School of Hygiene & Tropical Medicine, UK
- Global Health Division, International Development Group, RTI International, Research Triangle Park, NC, USA
| | | | - Doris Njomo
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Charles Mwandawiro
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Ulrike Fillinger
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | | | - Stella Kepha
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
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Uprety S, Ngo I, Maggos M, Dangol B, Sherchan SP, Shisler JL, Amarasiri M, Sano D, Nguyen TH. Multiple pathogen contamination of water, hands, and fomites in rural Nepal and the effect of WaSH interventions. Int J Hyg Environ Health 2024; 257:114341. [PMID: 38442666 DOI: 10.1016/j.ijheh.2024.114341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/23/2024] [Accepted: 02/16/2024] [Indexed: 03/07/2024]
Abstract
Water, Sanitation, and Hygiene (WaSH) interventions are the most effective in reducing diarrheal disease severity and prevalence. However, very few studies have investigated the effectiveness of WaSH intervention in reducing pathogen presence and concentration. In this study, we employed a microfluidic PCR approach to quantify twenty bacterial pathogens in water (n = 360), hands (n = 180), and fomite (n = 540) samples collected in rural households of Nepal to assess the pathogen exposures and the effect of WaSH intervention on contamination and exposure rates. The pathogen load and the exposure pathways for each pathogen in intervention and control villages were compared to understand the effects of WaSH intervention. Pathogens were detected in higher frequency and concentration from fomites samples, toilet handle (21.42%; 5.4,0 95%CI: mean log10 of 4.69, 5.96), utensils (23.5%; 5.47, 95%CI: mean log10 of 4.77, 6.77), and water vessels (22.42%; 5.53, 95%CI: mean log10 of 4.79, 6.60) as compared to cleaning water (14.36%; 5.05, 95%CI: mean log10 of 4.36, 5.89), drinking water (14.26%; 4.37, 85%CI: mean log10 of 4.37, 5.87), and hand rinse samples (16.92%; 5.49, 95%CI: mean log10 of 4.77, 6.39). There was no clear evidence that WaSH intervention reduced overall pathogen contamination in any tested pathway. However, we observed a significant reduction (p < 0.05) in the prevalence, but not concentration, of some target pathogens, including Enterococcus spp. in the intervention village compared to the control village for water and hands rinse samples. Conversely, no significant reduction in target pathogen concentration was observed for water and hand rinse samples. In swab samples, there was a reduction mostly in pathogen concentration rather than pathogen prevalence, highlighting that a reduction in pathogen prevalence was not always accompanied by a reduction in pathogen concentration. This study provides an understanding of WaSH intervention on microbe concentrations. Such data could help with better planning of intervention activities in the future.
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Affiliation(s)
- Sital Uprety
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, USA; Department of Sanitation, Water and Solid Waste for Development (Sandec), Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Zurich, Switzerland; Department of Civil and Environmental Engineering, Tohoku University Sendai, Japan.
| | - Isaac Ngo
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Marika Maggos
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Bipin Dangol
- Environment and Public Health Organization (ENPHO), Kathmandu, Nepal
| | - Samendra P Sherchan
- Environment and Public Health Organization (ENPHO), Kathmandu, Nepal; Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA; BioEnvironmental Science Program Morgan State University, Baltimore, MD, 21251, USA
| | - Joanna L Shisler
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Mohan Amarasiri
- School of Allied Health Sciences, Kitasato University, Sagamihara, Japan
| | - Daisuke Sano
- Department of Frontier Sciences for Advanced Environment, Tohoku University, Sendai, Japan; Department of Civil and Environmental Engineering, Tohoku University Sendai, Japan
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
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Mertens A, Arnold BF, Benjamin-Chung J, Boehm AB, Brown J, Capone D, Clasen T, Fuhrmeister ER, Grembi JA, Holcomb D, Knee J, Kwong LH, Lin A, Luby SP, Nala R, Nelson K, Njenga SM, Null C, Pickering AJ, Rahman M, Reese HE, Steinbaum L, Stewart JR, Thilakaratne R, Cumming O, Colford JM, Ercumen A. Is detection of enteropathogens and human or animal faecal markers in the environment associated with subsequent child enteric infections and growth: an individual participant data meta-analysis. Lancet Glob Health 2024; 12:e433-e444. [PMID: 38365415 PMCID: PMC10882208 DOI: 10.1016/s2214-109x(23)00563-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 11/13/2023] [Accepted: 11/28/2023] [Indexed: 02/18/2024]
Abstract
BACKGROUND Quantifying contributions of environmental faecal contamination to child diarrhoea and growth faltering can illuminate causal mechanisms behind modest health benefits in recent water, sanitation, and hygiene (WASH) trials. We aimed to assess associations between environmental detection of enteropathogens and human or animal microbial source tracking markers (MSTM) and subsequent child health outcomes. METHODS In this individual participant data meta-analysis we searched we searched PubMed, Embase, CAB Direct Global Health, Agricultural and Environmental Science Database, Web of Science, and Scopus for WASH intervention studies with a prospective design and concurrent control that measured enteropathogens or MSTM in environmental samples, or both, and subsequently measured enteric infections, diarrhoea, or height-for-age Z-scores (HAZ) in children younger than 5 years. We excluded studies that only measured faecal indicator bacteria. The initial search was done on Jan 19, 2021, and updated on March 22, 2023. One reviewer (AM) screened abstracts, and two independent reviewers (AM and RT) examined the full texts of short-listed articles. All included studies include at least one author that also contributed as an author to the present Article. Our primary outcomes were the 7-day prevalence of caregiver-reported diarrhoea and HAZ in children. For specific enteropathogens in the environment, primary outcomes also included subsequent child infection with the same pathogen ascertained by stool testing. We estimated associations using covariate-adjusted regressions and pooled estimates across studies. FINDINGS Data from nine published reports from five interventions studies, which included 8603 children (4302 girls and 4301 boys), were included in the meta-analysis. Environmental pathogen detection was associated with increased infection prevalence with the same pathogen and lower HAZ (ΔHAZ -0·09 [95% CI -0·17 to -0·01]) but not diarrhoea (prevalence ratio 1·22 [95% CI 0·95 to 1·58]), except during wet seasons. Detection of MSTM was not associated with diarrhoea (no pooled estimate) or HAZ (ΔHAZ -0·01 [-0·13 to 0·11] for human markers and ΔHAZ -0·02 [-0·24 to 0·21] for animal markers). Soil, children's hands, and stored drinking water were major transmission pathways. INTERPRETATION Our findings support a causal chain from pathogens in the environment to infection to growth faltering, indicating that the lack of WASH intervention effects on child growth might stem from insufficient reductions in environmental pathogen prevalence. Studies measuring enteropathogens in the environment should subsequently measure the same pathogens in stool to further examine theories of change between WASH, faecal contamination, and health. Given that environmental pathogen detection was predictive of infection, programmes targeting specific pathogens (eg, vaccinations and elimination efforts) can environmentally monitor the pathogens of interest for population-level surveillance instead of collecting individual biospecimens. FUNDING The Bill & Melinda Gates Foundation and the UK Foreign and Commonwealth Development Office.
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Affiliation(s)
- Andrew Mertens
- Division of Epidemiology, University of California, Berkeley, CA, USA; Division of Biostatistics, University of California, Berkeley, CA, USA.
| | - Benjamin F Arnold
- Francis I Proctor Foundation and Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Jade Benjamin-Chung
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA, USA
| | - Alexandria B Boehm
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Joe Brown
- Department of Environmental Science and Engineering, University of North Carolina, Gillings School of Global Public Health, Michael Hooker Research Center, Chapel Hill, NC, USA
| | - Drew Capone
- Department of Environmental and Occupational Health, Indiana University, Bloomington, IN, USA
| | - Thomas Clasen
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Erica R Fuhrmeister
- Department of Environmental & Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | | | - David Holcomb
- Department of Environmental Science and Engineering, University of North Carolina, Gillings School of Global Public Health, Michael Hooker Research Center, Chapel Hill, NC, USA
| | - Jackie Knee
- Department of Disease Control, London School of Tropical Medicine & Hygiene, London, UK
| | - Laura H Kwong
- Division of Environmental Health Sciences, University of California, Berkeley, CA, USA
| | - Audrie Lin
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
| | - Stephen P Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | - Rassul Nala
- Ministério da Saúde, Instituto Nacional de Saúde Maputo, Maputo, Mozambique
| | - Kara Nelson
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, CA, USA
| | | | | | - Amy J Pickering
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, CA, USA
| | - Mahbubur Rahman
- Environmental Interventions Unit, Infectious Diseases Division, Dhaka, Bangladesh
| | - Heather E Reese
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Lauren Steinbaum
- California Department of Toxic Substances Control, Sacramento, CA, USA
| | - Jill R Stewart
- Department of Environmental Science and Engineering, University of North Carolina, Gillings School of Global Public Health, Michael Hooker Research Center, Chapel Hill, NC, USA
| | | | - Oliver Cumming
- Department of Disease Control, London School of Tropical Medicine & Hygiene, London, UK
| | - John M Colford
- Division of Epidemiology, University of California, Berkeley, CA, USA
| | - Ayse Ercumen
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, USA
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Mothiba DP, Khabo-Mmekoa CM, Ngobeni-Nyambi R, Momba MNB. Assessing the Occurrence of Host-Specific Faecal Indicator Markers in Water Systems as a Function of Water, Sanitation and Hygiene Practices: A Case Study in Rural Communities of Vhembe District Municipality, South Africa. Pathogens 2023; 13:16. [PMID: 38251324 PMCID: PMC10819538 DOI: 10.3390/pathogens13010016] [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: 10/21/2023] [Revised: 12/06/2023] [Accepted: 12/18/2023] [Indexed: 01/23/2024] Open
Abstract
In settings where humans and animals closely coexist, the introduction of faecal material into unprotected water sources significantly increases the risk of contracting diarrhoeal and zoonotic waterborne diseases. The data were gathered from a survey conducted through interviews at randomly sampled villages; additionally, water samples were collected in randomly selected households and their associated feeder catchments. Molecular techniques were used, specifically qPCR, to run host-specific Bacteroides microbial source tracking (MST) assays for human, cattle, pig, chicken and dog faecal contamination. Unexpectedly, the qPCR assays revealed dogs to be the most prevalent (40.65%) depositor of faecal matter in unprotected surface water, followed by humans (40.63%); this finding was contradictory to survey findings indicating cattle as the leading source. At the household level, dogs (16.67%) and chickens (15.28%) played prominent roles, as was expected. Reflecting on some of the basic daily practices in households, nearly 89.00% of the population was found to store water due to erratic supply, in contrast to 93.23% using an improved water source. Additionally, a significant association was found between water, sanitation and hygiene (WASH) variables and the occurrence of MST markers after performing a bivariate linear regression. However, the inconsistency between the MST results and household surveys suggests pervasive sanitation issues, even in households without domesticated animals.
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Affiliation(s)
- Dikeledi Prudence Mothiba
- Department of Environmental, Water and Earth Sciences, Tshwane University of Technology, Arcadia Campus, Private Bag X680, Pretoria 0001, South Africa; (D.P.M.); (R.N.-N.)
| | | | - Renay Ngobeni-Nyambi
- Department of Environmental, Water and Earth Sciences, Tshwane University of Technology, Arcadia Campus, Private Bag X680, Pretoria 0001, South Africa; (D.P.M.); (R.N.-N.)
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602, South Africa
| | - Maggy Ndombo Benteke Momba
- Department of Environmental, Water and Earth Sciences, Tshwane University of Technology, Arcadia Campus, Private Bag X680, Pretoria 0001, South Africa; (D.P.M.); (R.N.-N.)
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Uprety S, Sherchan SP, Narayanan P, Dangol B, Maggos M, Celmer A, Shisler J, Amarasiri M, Sano D, Nguyen TH. Microbial assessment of water, sanitation, and hygiene (WaSH) in temporary and permanent settlements two years after Nepal 2015 earthquake. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162867. [PMID: 36931512 DOI: 10.1016/j.scitotenv.2023.162867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 03/10/2023] [Accepted: 03/10/2023] [Indexed: 05/06/2023]
Abstract
Disaster-induced displacement often causes people to live in temporary settlements that have limited infrastructure and access to water, sanitation, and hygiene (WaSH). Reducing the risk of diarrheal diseases in such situations requires knowing how housing influences the presence of pathogens in water and the interaction between human settlements and exposure to pathogens. A cross-sectional study was conducted in May 2017 in two communities hard-hit by the Nepal 2015 earthquake: one recovered with newly reconstructed houses, and one recovered with residents still living in sheet metal temporary shelters constructed after the earthquake. We collected 60 water (30 drinking water and 30 cleaning water), 30 hand rinse, and 90 environmental swab samples (30 toilet handles, 30 utensils, and 30 water vessels) from selected households in each location and quantified 22 bacterial pathogens using microfluidic quantitative polymerase chain reaction (mfqPCR). A total of 59 samples were randomly selected for amplicon-based sequencing of the 16S rRNA, and it identified bacterial community profiles between these two settlements and their association with target genes of pathogenic bacteria. Target genes like uidA of Escherichia coli and the mip gene of Legionella pnuemophila showed significantly high frequency in specific sample types in temporary settlements than in permanent settlements. A significantly high concentration was observed in temporary settlements for Enterococcus spp. and S. typhimurium, specifically in swab samples. There was a sharp distinction of microbial community profiles between water and hand rinse samples with environmental swab samples, with a large abundance of potentially pathogenic bacteria in swab samples in both settlements. This observation highlighted that fomite could be an important transmission route for pathogens in rural settings and designing key interventions to target different stages of transmission pathways is essential. Overall findings from this study suggest that the recovered settlement with higher quality housing may be less impacted by fecal contamination than recovering settlements and that interventions should be designed to disrupt multiple transmission pathways to reduce pathogen exposure.
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Affiliation(s)
- Sital Uprety
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, USA; Department of Sanitation, Water and Solid Waste for Development (Sandec), Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Zurich, Switzerland; Department of Civil and Environmental Engineering, Tohoku University, Sendai, Japan.
| | - Samendra P Sherchan
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, New Orleans, LA, USA; Department of Biology, Morgan State University, Baltimore, MD, USA
| | - Preeti Narayanan
- Department of Chemistry, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Bipin Dangol
- Environment and Public Health Organization (ENPHO), Kathmandu, Nepal
| | - Marika Maggos
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Alex Celmer
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Joanna Shisler
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Mohan Amarasiri
- Department of Health Science, School of Allied Health Sciences, Kitasato University, Sagamihara, Japan
| | - Daisuke Sano
- Department of Civil and Environmental Engineering, Tohoku University, Sendai, Japan
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
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Holcomb DA, Monteiro V, Capone D, António V, Chiluvane M, Cumbane V, Ismael N, Knee J, Kowalsky E, Lai A, Linden Y, Mataveia E, Nala R, Rao G, Ribeiro J, Cumming O, Viegas E, Brown J. Long-term impacts of an urban sanitation intervention on enteric pathogens in children in Maputo city, Mozambique: study protocol for a cross-sectional follow-up to the Maputo Sanitation (MapSan) trial 5 years postintervention. BMJ Open 2023; 13:e067941. [PMID: 37290945 PMCID: PMC10254709 DOI: 10.1136/bmjopen-2022-067941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 05/24/2023] [Indexed: 06/10/2023] Open
Abstract
INTRODUCTION We previously assessed the effect of an onsite sanitation intervention in informal neighbourhoods of urban Maputo, Mozambique on enteric pathogen detection in children after 2 years of follow-up (Maputo Sanitation (MapSan) trial, ClinicalTrials.gov: NCT02362932). We found significant reductions in Shigella and Trichuris prevalence but only among children born after the intervention was delivered. In this study, we assess the health impacts of the sanitation intervention after 5 years among children born into study households postintervention. METHODS AND ANALYSIS We are conducting a cross-sectional household study of enteric pathogen detection in child stool and the environment at compounds (household clusters sharing sanitation and outdoor living space) that received the pour-flush toilet and septic tank intervention at least 5 years prior or meet the original criteria for trial control sites. We are enrolling at least 400 children (ages 29 days to 60 months) in each treatment arm. Our primary outcome is the prevalence of 22 bacterial, protozoan, and soil transmitted helminth enteric pathogens in child stool using the pooled prevalence ratio across the outcome set to assess the overall intervention effect. Secondary outcomes include the individual pathogen detection prevalence and gene copy density of 27 enteric pathogens (including viruses); mean height-for-age, weight-for-age, and weight-for-height z-scores; prevalence of stunting, underweight, and wasting; and the 7-day period prevalence of caregiver-reported diarrhoea. All analyses are adjusted for prespecified covariates and examined for effect measure modification by age. Environmental samples from study households and the public domain are assessed for pathogens and faecal indicators to explore environmental exposures and monitor disease transmission. ETHICS AND DISSEMINATION Study protocols have been reviewed and approved by human subjects review boards at the Ministry of Health, Republic of Mozambique and the University of North Carolina at Chapel Hill. Deidentified study data will be deposited at https://osf.io/e7pvk/. TRIAL REGISTRATION NUMBER ISRCTN86084138.
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Affiliation(s)
- David A Holcomb
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Vanessa Monteiro
- Centro de Investigação e Treino em Saúde da Polana Caniço, Instituto Nacional de Saúde, Maputo, Mozambique
| | - Drew Capone
- Department of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, Indiana, USA
| | - Virgílio António
- Division of Biotechnology and Genetics, Instituto Nacional de Saúde, Marracuene, Mozambique
| | - Márcia Chiluvane
- Centro de Investigação e Treino em Saúde da Polana Caniço, Instituto Nacional de Saúde, Maputo, Mozambique
| | - Victória Cumbane
- Centro de Investigação e Treino em Saúde da Polana Caniço, Instituto Nacional de Saúde, Maputo, Mozambique
| | - Nália Ismael
- Division of Biotechnology and Genetics, Instituto Nacional de Saúde, Marracuene, Mozambique
| | - Jackie Knee
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Erin Kowalsky
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Amanda Lai
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Yarrow Linden
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Elly Mataveia
- Centro de Investigação e Treino em Saúde da Polana Caniço, Instituto Nacional de Saúde, Maputo, Mozambique
| | - Rassul Nala
- Division of Parasitology, Instituto Nacional de Saúde, Maputo, Mozambique
| | - Gouthami Rao
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jorge Ribeiro
- Centro de Investigação e Treino em Saúde da Polana Caniço, Instituto Nacional de Saúde, Maputo, Mozambique
| | - Oliver Cumming
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Edna Viegas
- Centro de Investigação e Treino em Saúde da Polana Caniço, Instituto Nacional de Saúde, Maputo, Mozambique
| | - Joe Brown
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
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Capone D, Bivins A, Brown J. Producing ratio measures of effect with quantitative microbial risk assessment. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2023. [PMID: 35689350 DOI: 10.17605/osf.io/jwzy9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Estimating the risk of infections or other outcomes incident to pathogen exposure is a primary goal of quantitative microbial risk assessment (QMRA). Such estimates are useful to predict population-level risks, to evaluate exposures based on normative or tolerable risk guidelines, and to interpret the likely public health relevance of microbial measurements in environmental media. To evaluate alternative control measures (interventions), ratio estimates of effect (e.g., odds and risk ratios) are needed that are more broadly interpretable in the health sciences and consistent with convention in epidemiology. In this paper, we propose a general method for estimating widely used ratio measures of effect derived from stochastic QMRA approaches, including the generation of appropriate confidence intervals. Such QMRA-derived ratios can be used as a basis for evaluating interventions via hypothesis testing and for inclusion in systematic reviews and meta-analyses in a form consistent with risk estimation approaches commonly used in epidemiology.
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Affiliation(s)
- Drew Capone
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Aaron Bivins
- Department of Civil & Environmental Engineering, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Joe Brown
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Capone D, Bivins A, Brown J. Producing ratio measures of effect with quantitative microbial risk assessment. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2023; 43:917-927. [PMID: 35689350 PMCID: PMC9734285 DOI: 10.1111/risa.13972] [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: 01/21/2022] [Revised: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 05/06/2023]
Abstract
Estimating the risk of infections or other outcomes incident to pathogen exposure is a primary goal of quantitative microbial risk assessment (QMRA). Such estimates are useful to predict population-level risks, to evaluate exposures based on normative or tolerable risk guidelines, and to interpret the likely public health relevance of microbial measurements in environmental media. To evaluate alternative control measures (interventions), ratio estimates of effect (e.g., odds and risk ratios) are needed that are more broadly interpretable in the health sciences and consistent with convention in epidemiology. In this paper, we propose a general method for estimating widely used ratio measures of effect derived from stochastic QMRA approaches, including the generation of appropriate confidence intervals. Such QMRA-derived ratios can be used as a basis for evaluating interventions via hypothesis testing and for inclusion in systematic reviews and meta-analyses in a form consistent with risk estimation approaches commonly used in epidemiology.
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Affiliation(s)
- Drew Capone
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Aaron Bivins
- Louisiana State University, Baton Rouge, Louisiana, USA
| | - Joe Brown
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Ballard AM, Laramee N, Haardörfer R, Freeman MC, Levy K, Caruso BA. Measurement in the study of human exposure to animal feces: A systematic review and audit. Int J Hyg Environ Health 2023; 249:114146. [PMID: 36868140 PMCID: PMC10044406 DOI: 10.1016/j.ijheh.2023.114146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/31/2023] [Accepted: 02/23/2023] [Indexed: 03/05/2023]
Abstract
BACKGROUND Human exposure to animal feces is increasingly recognized as an important transmission route of enteric pathogens. Yet, there are no consistent or standardized approaches to measurement of this exposure, limiting assessment of the human health effects and scope of the issue. OBJECTIVE To inform and improve approaches to the measurement of human exposure to animal feces, we audited existing measurement in low- and middle-income countries. METHODS We systematically searched peer-reviewed and gray literature databases for studies with quantitative measures of human exposure to animal feces and we classified measures in two ways. First, using a novel conceptual model, we categorized measures into three 'Exposure Components' identified a priori (i.e., Animal, Environmental, Human Behavioral); one additional Component (Evidence of Exposure) inductively emerged. Second, using the exposure science conceptual framework, we determined where measures fell along the source-to-outcome continuum. RESULTS We identified 1,428 measures across 184 included studies. Although studies overwhelmingly included more than one single-item measure, the majority only captured one Exposure Component. For example, many studies used several single-item measures to capture the same attribute for different animals, all of which were classified as the same Component. Most measures captured information about the source (e.g. animal presence) and contaminant (e.g. animal-sourced pathogens), which are most distal from exposure on the source-to-outcome continuum. DISCUSSION We found that measurement of human exposure to animal feces is diverse and largely distal from exposure. To facilitate better assessment of the human health effects of exposure and scope of the issue, rigorous and consistent measures are needed. We recommend a list of key factors from the Animal, Environmental, and Human Behavioral Exposure Components to measure. We also propose using the exposure science conceptual framework to identify proximal measurement approaches.
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Affiliation(s)
- April M Ballard
- Gangarosa Department of Environmental Health, Emory University Rollins School of Public Health, Atlanta, GA, USA.
| | - Nicholas Laramee
- Hubert Department of Global Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | - Regine Haardörfer
- Department of Behavioral, Social and Health Education Sciences, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | - Matthew C Freeman
- Gangarosa Department of Environmental Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | - Karen Levy
- Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA, USA
| | - Bethany A Caruso
- Gangarosa Department of Environmental Health, Emory University Rollins School of Public Health, Atlanta, GA, USA; Hubert Department of Global Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
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10
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Mertens A, Arnold BF, Benjamin-Chung J, Boehm AB, Brown J, Capone D, Clasen T, Fuhrmeister E, Grembi JA, Holcomb D, Knee J, Kwong LH, Lin A, Luby SP, Nala R, Nelson K, Njenga SM, Null C, Pickering AJ, Rahman M, Reese HE, Steinbaum L, Stewart J, Thilakaratne R, Cumming O, Colford JM, Ercumen A. Effects of water, sanitation, and hygiene interventions on detection of enteropathogens and host-specific faecal markers in the environment: a systematic review and individual participant data meta-analysis. Lancet Planet Health 2023; 7:e197-e208. [PMID: 36889861 PMCID: PMC10009758 DOI: 10.1016/s2542-5196(23)00028-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 01/25/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Water, sanitation, and hygiene (WASH) improvements are promoted to reduce diarrhoea in low-income countries. However, trials from the past 5 years have found mixed effects of household-level and community-level WASH interventions on child health. Measuring pathogens and host-specific faecal markers in the environment can help investigate causal pathways between WASH and health by quantifying whether and by how much interventions reduce environmental exposure to enteric pathogens and faecal contamination from human and different animal sources. We aimed to assess the effects of WASH interventions on enteropathogens and microbial source tracking (MST) markers in environmental samples. METHODS We did a systematic review and individual participant data meta-analysis, which included searches from Jan 1, 2000, to Jan 5, 2023, from PubMed, Embase, CAB Direct Global Health, Agricultural and Environmental Science Database, Web of Science, and Scopus, of prospective studies with water, sanitation, or hygiene interventions and concurrent control group that measured pathogens or MST markers in environmental samples and measured child anthropometry, diarrhoea, or pathogen-specific infections. We used covariate-adjusted regression models with robust standard errors to estimate study-specific intervention effects and pooled effect estimates across studies using random-effects models. FINDINGS Few trials have measured the effect of sanitation interventions on pathogens and MST markers in the environment and they mostly focused on onsite sanitation. We extracted individual participant data on nine environmental assessments from five eligible trials. Environmental sampling included drinking water, hand rinses, soil, and flies. Interventions were consistently associated with reduced pathogen detection in the environment but effect estimates in most individual studies could not be distinguished from chance. Pooled across studies, we found a small reduction in the prevalence of any pathogen in any sample type (pooled prevalence ratio [PR] 0·94 [95% CI 0·90-0·99]). Interventions had no effect on the prevalence of MST markers from humans (pooled PR 1·00 [95% CI 0·88-1·13]) or animals (pooled PR 1·00 [95% CI 0·97-1·03]). INTERPRETATION The small effect of these sanitation interventions on pathogen detection and absence of effects on human or animal faecal markers are consistent with the small or null health effects previously reported in these trials. Our findings suggest that the basic sanitation interventions implemented in these studies did not contain human waste and did not adequately reduce exposure to enteropathogens in the environment. FUNDING Bill and Melinda Gates Foundation and the UK Foreign and Commonwealth Development Office.
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Affiliation(s)
- Andrew Mertens
- Division of Epidemiology and Biostatistics, University of California, Berkeley, CA, USA.
| | - Benjamin F Arnold
- Francis I Proctor Foundation and Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Jade Benjamin-Chung
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA, USA
| | - Alexandria B Boehm
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Joe Brown
- Department of Environmental Science and Engineering, Gillings School of Global Public Health, Michael Hooker Research Center, University of North Carolina, Chapel Hill, NC, USA
| | - Drew Capone
- Department of Environmental and Occupational Health, Indiana University Bloomington, Bloomington, IN, USA
| | - Thomas Clasen
- Department of Environmental Health, Rollins School of Public Health, Emory University, NE, Atlanta, GA, USA
| | - Erica Fuhrmeister
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | | | - David Holcomb
- Department of Environmental Science and Engineering, Gillings School of Global Public Health, Michael Hooker Research Center, University of North Carolina, Chapel Hill, NC, USA
| | - Jackie Knee
- Department of Disease Control, London School of Tropical Medicine & Hygiene, London, UK
| | - Laura H Kwong
- Division of Environmental Health Sciences, University of California, Berkeley, CA, USA
| | - Audrie Lin
- Department of Biobehavioral Health, Pennsylvania State University, PA, USA
| | - Stephen P Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | - Rassul Nala
- Ministério da Saúde, Instituto Nacional de Saúde Maputo, Maputo, Mozambique
| | - Kara Nelson
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, CA, USA
| | | | | | - Amy J Pickering
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, CA, USA
| | - Mahbubur Rahman
- Environmental Interventions Unit, Infectious Diseases Division, Dhaka, Bangladesh
| | - Heather E Reese
- Department of Environmental Health, Rollins School of Public Health, Emory University, NE, Atlanta, GA, USA
| | - Lauren Steinbaum
- Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
| | - Jill Stewart
- Department of Environmental Science and Engineering, Gillings School of Global Public Health, Michael Hooker Research Center, University of North Carolina, Chapel Hill, NC, USA
| | - Ruwan Thilakaratne
- Division of Epidemiology and Biostatistics, University of California, Berkeley, CA, USA
| | - Oliver Cumming
- Department of Disease Control, London School of Tropical Medicine & Hygiene, London, UK
| | - John M Colford
- Division of Epidemiology and Biostatistics, University of California, Berkeley, CA, USA
| | - Ayse Ercumen
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, USA
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11
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Capone D, Adriano Z, Cumming O, Irish SR, Knee J, Nala R, Brown J. Urban Onsite Sanitation Upgrades and Synanthropic Flies in Maputo, Mozambique: Effects on Enteric Pathogen Infection Risks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:549-560. [PMID: 36516327 PMCID: PMC9835884 DOI: 10.1021/acs.est.2c06864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/30/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
Synanthropic filth flies transport enteric pathogens from feces to food, which upon consumption poses an infection risk. We evaluated the effect of an onsite sanitation intervention─including fly control measures─in Maputo, Mozambique, on the risk of infection from consuming fly-contaminated food. After enumerating flies at intervention and control sites, we cultured fecal indicator bacteria, quantified gene copies for 22 enteric pathogens via reverse transcription quantitative polymerase chain reaction (RT-qPCR), and developed quantitative microbial risk assessment (QMRA) models to estimate annual risks of infection attributable to fly-contaminated foods. We found that the intervention reduced fly counts at latrine entrances by 69% (aRR = 0.31, [0.13, 0.75]) but not at food preparation areas (aRR = 0.92, [0.33, 2.6]). Half of (23/46) of individual flies were positive for culturable Escherichia coli, and we detected ≥1 pathogen gene from 45% (79/176) of flies, including enteropathogenic E. coli (37/176), adenovirus (25/176), Giardia spp. (13/176), and Trichuris trichiura (12/176). We detected ≥1 pathogen gene from half the flies caught in control (54%, 30/56) and intervention compounds (50%, 17/34) at baseline, which decreased 12 months post-intervention to 43% (23/53) at control compounds and 27% (9/33) for intervention compounds. These data indicate flies as a potentially important mechanical vector for enteric pathogen transmission in this setting. The intervention may have reduced the risk of fly-mediated enteric infection for some pathogens, but infrequent detection resulted in wide confidence intervals; we observed no apparent difference in infection risk between groups in a pooled estimate of all pathogens assessed (aRR = 0.84, [0.61, 1.2]). The infection risks posed by flies suggest that the design of sanitation systems and service delivery should include fly control measures to prevent enteric pathogen transmission.
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Affiliation(s)
- Drew Capone
- Department
of Environmental and Occupational Health, School of Public Health, Indiana University, 2719 E 10th St, Bloomington, Indiana47401, United States
| | - Zaida Adriano
- WE
Consult ltd, 177 Rua
Tomas Ribeiro, Maputo1102, Mozambique
| | - Oliver Cumming
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, LondonWC1E 7HT, United
Kingdom
| | - Seth R. Irish
- Epidemiology
and Public Health Department, Swiss Tropical
and Public Health Institute, Kreuzstrasse 2, Allschwil4123, Switzerland
| | - Jackie Knee
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, LondonWC1E 7HT, United
Kingdom
| | - Rassul Nala
- Ministério
da Saúde, Instituto Nacional de Saúde
Maputo, Maputo1102, Mozambique
| | - Joe Brown
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
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12
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Capone D, Barker T, Cumming O, Flemister A, Geason R, Kim E, Knee J, Linden Y, Manga M, Meldrum M, Nala R, Smith S, Brown J. Persistent Ascaris Transmission Is Possible in Urban Areas Even Where Sanitation Coverage Is High. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15969-15980. [PMID: 36288473 PMCID: PMC9671051 DOI: 10.1021/acs.est.2c04667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
In low-income, urban, informal communities lacking sewerage and solid waste services, onsite sanitation (sludges, aqueous effluent) and child feces are potential sources of human fecal contamination in living environments. Working in informal communities of urban Maputo, Mozambique, we developed a quantitative, stochastic, mass-balance approach to evaluate plausible scenarios of localized contamination that could explain why the soil-transmitted helminth Ascaris remains endemic despite nearly universal coverage of latrines that sequester most fecal wastes. We used microscopy to enumerate presumptively viable Ascaris ova in feces, fecal sludges, and soils from compounds (i.e., household clusters) and then constructed a steady-state mass-balance model to evaluate possible contamination scenarios capable of explaining observed ova counts in soils. Observed Ascaris counts (mean = -0.01 log10 ova per wet gram of soil, sd = 0.71 log10) could be explained by deposits of 1.9 grams per day (10th percentile 0.04 grams, 90th percentile 84 grams) of child feces on average, rare fecal sludge contamination events that transport 17 kg every three years (10th percentile 1.0 kg, 90th percentile 260 kg), or a daily discharge of 2.7 kg aqueous effluent from an onsite system (10th percentile 0.09 kg, 90th percentile 82 kg). Results suggest that even limited intermittent flows of fecal wastes in this setting can result in a steady-state density of Ascaris ova in soils capable of sustaining transmission, given the high prevalence of Ascaris shedding by children (prevalence = 25%; mean = 3.7 log10 per wet gram, sd = 1.1 log10), the high Ascaris ova counts in fecal sludges (prevalence = 88%; mean = 1.8 log10 per wet gram, sd = 0.95 log10), and the extended persistence and viability of Ascaris ova in soils. Even near-universal coverage of onsite sanitation may allow for sustained transmission of Ascaris under these conditions.
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Affiliation(s)
- Drew Capone
- Department
of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, Indiana47401, United States
| | - Troy Barker
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Oliver Cumming
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, LondonWC1E 7HT, U.K.
| | - Abeoseh Flemister
- Department
of Biology, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Riley Geason
- Department
of Biology, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Elizabeth Kim
- Department
of Biology, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Jackie Knee
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, LondonWC1E 7HT, U.K.
| | - Yarrow Linden
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Musa Manga
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
| | - Mackenzie Meldrum
- Department
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia30332, United States
| | - Rassul Nala
- Ministério
da Saúde, Instituto Nacional de Saúde
Maputo, Maputo1102, Mozambique
| | - Simrill Smith
- Department
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia30332, United States
| | - Joe Brown
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel
Hill, North Carolina27599, United States
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13
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Gizaw Z, Yalew AW, Bitew BD, Lee J, Bisesi M. Stunting among children aged 24-59 months and associations with sanitation, enteric infections, and environmental enteric dysfunction in rural northwest Ethiopia. Sci Rep 2022; 12:19293. [PMID: 36369357 PMCID: PMC9652362 DOI: 10.1038/s41598-022-23981-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 11/08/2022] [Indexed: 11/13/2022] Open
Abstract
Stunting is a public health issue of global concern. Despite, poor sanitation, diarrhea, parasitic infections, and environmental enteric dysfunction (EED) are associated with stunting, their link is poorly understood and has not been investigated in Ethiopia. This study was conducted to assess the associations of stunting with sanitation, enteric infections, and EED among children aged 24-59 months in rural northwest Ethiopia. A community-based cross-sectional study was conducted among 224 randomly selected children aged 24-59 months in rural areas of the east Dembiya district. We collected information on household food insecurity and dietary diversity using pre-tested questionnaires adopted from the food and nutrition technical assistance (FANTA) project. We used height-for-age-z score (HAZ) to define stunting. We also used the data collected to measure the environmental exposures of children to intestinal parasitic infections and fecal biomarkers of EED. A multivariable binary logistic regression model was used to assess the association of stunting with sanitation, enteric infections, and EED. Of the 224 children, 33% (95% CI 27, 39%) were stunted. Stunting in children was significantly associated with poor dietary intake (AOR 3.0, 95% CI 1.2, 7.3), open defecation practice (AOR 3.0, 95% CI 1.2, 7.9), presence of animal excreta in the living environment (AOR 3.4, 95% CI 1.2, 9.9), E. coli contamination of drinking water (AOR 4.2, 95% CI 1.1, 15.3), diarrheal disease incidence (AOR 3.4, 95% CI 1.5, 7.7), intestinal parasites in children (AOR 3.3, 95% CI 1.3, 8.8), and higher EED disease activity scores (AOR 2.9, 95% CI 1.2, 6.7). One-third of the children in the study area were stunted and this high prevalence of stunting was associated with poor dietary intake, poor hygiene and sanitation conditions, enteric infections, and EED. Thus, stunting can be prevented by improving sanitation and hygienic conditions to prevent repeated enteric infections in children and by promoting dietary diversity of children.
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Affiliation(s)
- Zemichael Gizaw
- grid.59547.3a0000 0000 8539 4635Department of Environmental and Occupational Health and Safety, Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia ,grid.458355.a0000 0004 9341 7904Addis Continental Institute of Public Health, Addis Ababa, Ethiopia ,grid.261331.40000 0001 2285 7943Global One Health Initiative (GOHi), The Ohio State University, Columbus, OH USA
| | - Alemayehu Worku Yalew
- grid.7123.70000 0001 1250 5688School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Bikes Destaw Bitew
- grid.59547.3a0000 0000 8539 4635Department of Environmental and Occupational Health and Safety, Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Jiyoung Lee
- grid.261331.40000 0001 2285 7943Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH 43210 USA ,grid.261331.40000 0001 2285 7943Department of Food Science and Technology, The Ohio State University, Columbus, OH USA
| | - Michael Bisesi
- grid.261331.40000 0001 2285 7943Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH 43210 USA
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14
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Lowe J, Ercumen A, Prottas C, Harris AR. Exploring the determinants and indicators of poultry feces management behaviors in rural Western Uganda. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155202. [PMID: 35421491 DOI: 10.1016/j.scitotenv.2022.155202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 03/23/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
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.
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Affiliation(s)
- Jeremy Lowe
- Department of Civil, Construction, and Environmental Engineering, NC State University, Raleigh, NC, United States.
| | - Ayse Ercumen
- Department of Forestry and Environmental Resources, NC State University, Raleigh, NC, United States.
| | | | - Angela R Harris
- Department of Civil, Construction, and Environmental Engineering, NC State University, Raleigh, NC, United States.
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15
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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. 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. PLoS Med 2022; 19:e1004041. [PMID: 35939520 PMCID: PMC9394830 DOI: 10.1371/journal.pmed.1004041] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 08/22/2022] [Accepted: 06/02/2022] [Indexed: 12/30/2022] Open
Abstract
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. METHODS AND FINDINGS WASH Benefits Bangladesh was a cluster-randomized controlled trial of water, sanitation, hygiene, and nutrition interventions (NCT01590095). The sanitation intervention included provision of or upgrades to improved latrines, sani-scoops for feces removal, children's potties, and in-person behavioral promotion. Promotion was intensive up to 2 years after intervention initiation, decreased in intensity between years 2 to 3, and stopped after 3 years. Access to and reported use of latrines was high in both arms, and latrine quality was significantly improved by the intervention, while use of child feces management tools was low. We enrolled a random subset of households from the sanitation and control arms into a longitudinal substudy, which measured child health with quarterly visits between 1 to 3.5 years after intervention implementation. The study period therefore included approximately 1 year of high-intensity promotion, 1 year of low-intensity promotion, and 6 months with no promotion. We assessed intervention effects on diarrhea and ARI prevalence among children <5 years through intention-to-treat analysis using generalized linear models with robust standard errors. Masking was not possible during data collection, but data analysis was masked. We enrolled 720 households (360 per arm) from the parent trial and made 9,800 child observations between June 2014 and December 2016. Over the entire study period, diarrheal prevalence was lower among children in the sanitation arm (11.9%) compared to the control arm (14.5%) (prevalence ratio [PR] = 0.81, 95% CI 0.66, 1.00, p = 0.05; prevalence difference [PD] = -0.027, 95% CI -0.053, 0, p = 0.05). ARI prevalence did not differ between sanitation (21.3%) and control (22.7%) arms (PR = 0.93, 95% CI 0.82, 1.05, p = 0.23; PD = -0.016, 95% CI -0.043, 0.010, p = 0.23). There were no significant differences in intervention effects between periods with high-intensity versus low-intensity/no promotion. Study limitations include use of caregiver-reported symptoms to define health outcomes and limited data collected after promotion ceased. CONCLUSIONS The observed effect of the WASH Benefits Bangladesh sanitation intervention on diarrhea in children appeared to be sustained for at least 3.5 years after implementation, including 1.5 years after heavy promotion ceased. Existing latrine access was high in the study setting, suggesting that improving on-site latrine quality can deliver health benefits when latrine use practices are in place. Further work is needed to understand how latrine adoption can be achieved and sustained in settings with low existing access and how sanitation programs can adopt transformative approaches of excreta management, including safe disposal of child and animal feces, to generate a hygienic home environment. TRIAL REGISTRATION ClinicalTrials.gov; NCT01590095; https://clinicaltrials.gov/ct2/show/NCT01590095.
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Affiliation(s)
- Jesse D. Contreras
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Mahfuza Islam
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, Bangladesh
| | - Andrew Mertens
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Amy J. Pickering
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, United States of America
| | - Benjamin F. Arnold
- Francis I. Proctor Foundation, University of California, San Francisco, California, United States of America
| | - Jade Benjamin-Chung
- Department of Epidemiology and Population Health, Stanford University, Palo Alto, California, United States of America
| | - Alan E. Hubbard
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Mahbubur Rahman
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, Bangladesh
| | - Leanne Unicomb
- Environmental Interventions Unit, Infectious Disease Division, icddr,b, Dhaka, Bangladesh
| | - Stephen P. Luby
- Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, United States of America
| | - John M. Colford
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Ayse Ercumen
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail:
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16
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Gizaw Z, Yalew AW, Bitew BD, Lee J, Bisesi M. Fecal biomarkers of environmental enteric dysfunction and associated factors among children aged 24-59 months in east Dembiya district, northwest Ethiopia. BMC Gastroenterol 2022; 22:172. [PMID: 35395735 PMCID: PMC8994394 DOI: 10.1186/s12876-022-02255-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 03/30/2022] [Indexed: 11/23/2022] Open
Abstract
Background Environmental enteric dysfunction is a subclinical intestinal disorder characterized by gut inflammation accompanied by morphological changes, such as blunted villi and crypt hyperplasia. This is a common illness in low and middle-income countries. However, environmental enteric dysfunction evidence is limited in Ethiopia. Accordingly, this study was conducted to measure fecal biomarkers of environmental enteric dysfunction and associated factors among children aged 24–59 months in rural northwest Ethiopia. Methods A community-based cross-sectional study was employed among 235 randomly selected children in a rural setting of the east Dembiya district. Stool samples were collected without fixative and analyzed for fecal biomarkers of environmental enteric dysfunction (Alpha-1-antitrypsin, neopterin, and myeloperoxidase) using commercial enzyme-linked immunosorbent assay kits and analyzed for intestinal parasites using wet mount and Kato-Katz techniques. Child behaviors related with exposure to enteropathogens, condition of the living environment and socio-demographic information were collected using interviewer-administered questionnaire and structure observation. We fitted multivariable linear regression model to assess the association between environmental factors and concentration of fecal biomarkers of environmental enteric dysfunction in the stool. Statistically significant associations were declared based on adjusted betas with the corresponding 95% confidence interval and p-value < 0.05. Results The median concentration of fecal markers of environmental enteric dysfunction was 350 μg/ml for Alpha-1-antitrypsin, 3320.2 ng/ml for myeloperoxidase, and 1562 nmol/l for neopterin. The median concentration of Alpha-1-antitrypsin among 161 (68.5%), myeloperoxidase among 168 (71.5%), and neopterin among 188 (80%) of the stool samples were above the normal values in non-tropical settings. Moreover, 100 (42.6%) of the children had high EED disease activity score (above the median score). The elevated concentrations of fecal biomarkers of gut inflammation and the high EED disease activity score were significantly associated with open defecation practice, mouthing of soil contaminated materials, Escherichia coli (E. coli) contamination of drinking water, E. coli contamination of foods, E. coli contamination of soil, and intestinal parasites. Conclusion Overall, Alpha-1-antitrypsin, myeloperoxidase, and neopterin levels among the children in the studied region were highly elevated in comparison to populations in high-income countries. Moreover, the EED disease activity score in significant proportion of children was high, suggesting widespread intestinal inflammation and increased intestinal permeability. Extensive E. coli contamination of the living environment (drinking water, ready-to-eat foods, and courtyard soil), hygiene and sanitation behaviors (such as open defecation and mouthing of soil contaminated materials), and a high burden of intestinal parasites were identified as factors associated with the elevated concentration of fecal biomarkers of environmental enteric dysfunction. Parental care to children to avoid mouthing of soil contaminated materials and other risky behaviors that increase exposure enteric infections, and protecting the living environment (water, food and soil) from fecal contamination are important.
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Affiliation(s)
- Zemichael Gizaw
- Department of Environmental and Occupational Health and Safety, Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia. .,Addis Continental Institute of Public Health, Addis Ababa, Ethiopia. .,Global One Health Initiative (GOHi), The Ohio State University, Columbus, OH, USA.
| | | | - Bikes Destaw Bitew
- Department of Environmental and Occupational Health and Safety, Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Jiyoung Lee
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH, 43210, USA.,Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA
| | - Michael Bisesi
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH, 43210, USA
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Site specific incidence rate of genomic subtypes of enteropathogenic Escherichia coli and association with enteric inflammation and child growth. Sci Rep 2022; 12:5724. [PMID: 35388098 PMCID: PMC8986875 DOI: 10.1038/s41598-022-09730-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 03/16/2022] [Indexed: 02/01/2023] Open
Abstract
There is a lack of information highlighting the possible association between the genomic subtypes of enteropathogenic Escherichia coli (EPEC) on environmental enteric dysfunction (EED) and on linear growth during childhood. Genomic subtypes of EPEC from stool samples collected from 1705 children enrolled in the MAL-ED birth cohort were detected by TaqMan Array Cards. We measured site-specific incidence rate by using Poisson regression models, identified the risk factors and estimated the association of genomic subtypes of EPEC with the composite EED score and linear growth at 24 months of age. In general, the highest incidence rate (39%) was found among children having aEPEC infection, which was the greatest in Tanzania (54%). Exclusive breastfeeding and having an improved sanitation facility were found to be protective factors against EPEC infection. In the multivariate models, in overall effect after adjusting for the potential covariates aEPEC showed strong positive associations with the EED scores and tEPEC showed a positive association with poor linear growth at 24 months of age. Our analyses may lay the cornerstone for a prospective epidemiologic investigation for a potential vaccine development aimed at reducing the burden of EPEC infections and combat childhood malnutrition.
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Gizaw Z, Yalew AW, Bitew BD, Lee J, Bisesi M. Fecal indicator bacteria along multiple environmental exposure pathways (water, food, and soil) and intestinal parasites among children in the rural northwest Ethiopia. BMC Gastroenterol 2022; 22:84. [PMID: 35220951 PMCID: PMC8882269 DOI: 10.1186/s12876-022-02174-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 02/21/2022] [Indexed: 12/13/2022] Open
Abstract
Background Children in low-resource settings are exposed to multiple risk factors for enteropathogens. However, the probability of exposures may be different across exposure pathways. Accordingly, this study was conducted to assess environmental exposures of children to intestinal parasites in the east Dembiya district of Ethiopia.
Methods A cross-sectional study was conducted for 372 households with children aged 24–59 months. The potential for external exposure of children to intestinal parasites was assessed by determining the presence of fecal indicator organism (Escherichia coli (E. coli)) in drinking water at point of use, ready-to-eat foods, and courtyard soil from children’s outdoor play areas. For internal exposure assessment, ova of parasites in stool samples was detected using wet mount and Kato-Katz techniques to estimate exposure to intestinal parasites. The external and internal exposure assessments were also complemented using questionnaire and spot-check observations to assess behaviors that result in high risk of exposure. Individual and community-level predictors of intestinal parasites were identified using a multilevel logistic regression model. Statistically significant variables were identified on the basis of adjusted odds ratio (AOR) with 95% confidence interval (CI) and p-value < 0.05.
Results Ova of one or more intestinal parasites was detected among 178 (47.8%) (95% CI 42.8, 52.6%) of the children. The most common intestinal parasites were A. lumbricoides (20.7%) and S. mansoni (19.1%). Furthermore, E. coli was detected in 69.1% of drinking water samples at point of use, 67.5% of ready-to-eat food samples, and 83.1% of courtyard soil samples from children’s outdoor play areas. Exposure of children to intestinal parasites among children in the studied region was associated with poor hand hygiene of mothers (AOR 1.98, 95% CI (1.07, 3.66), poor hand hygiene of children (AOR 3.20, 95% CI (1.77, 5.77), mouthing of soil contaminated materials (AOR 2.31, 95% CI (1.26, 4.24), open defecation practices (AOR 2.22, 95% CI (1.20, 4.10), limited access to water (AOR 2.38, 95% CI (1.13, 5.01), water contamination (AOR 2.51, 95% CI (1.31, 4.80), food contamination (AOR 3.21, 95% CI (1.69, 6.09), and soil contamination (AOR 2.56, 95% CI (1.34, 4.90). Conclusion An extensive E. coli contamination of water, foods, and courtyard soil was found in the studied region and the potential sources of contamination were open defecation practices, unhygienic disposal of wastes, poor animal husbandry and keeping practices, and poor water and food safety measures at household level. Moreover, fecal contamination of water, foods, and soil linked to exposure of children to intestinal parasites in the studied region. Thus, it is critical to implement individual-level interventions (such as latrine utilization, hand hygiene promotion, food safety, home-based water treatment, and containment of domestic animals), plus community-level interventions (such as protecting water sources from contamination, source-based water treatment, and community-driven sanitation).
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Amato HK, Hemlock C, Andrejko KL, Smith AR, Hejazi NS, Hubbard AE, Verma SC, Adhikari RK, Pokhrel D, Smith K, Graham JP, Pokhrel A. Biodigester Cookstove Interventions and Child Diarrhea in Semirural Nepal: A Causal Analysis of Daily Observations. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:17002. [PMID: 34985305 PMCID: PMC8729225 DOI: 10.1289/ehp9468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 11/02/2021] [Accepted: 12/02/2021] [Indexed: 05/08/2023]
Abstract
BACKGROUND Hundreds of thousands of biodigesters have been constructed in Nepal. These household-level systems use human and animal waste to produce clean-burning biogas used for cooking, which can reduce household air pollution from woodburning cookstoves and prevent respiratory illnesses. The biodigesters, typically operated by female caregivers, require the handling of animal waste, which may increase domestic fecal contamination, exposure to diarrheal pathogens, and the risk of enteric infections, especially among young children. OBJECTIVE We estimated the effect of daily reported biogas cookstove use on incident diarrhea among children < 5 y old in the Kavrepalanchok District of Nepal. Secondarily, we assessed effect measure modification and statistical interaction of individual- and household-level covariates (child sex, child age, birth order, exclusive breastfeeding, proof of vaccination, roof type, sanitation, drinking water treatment, food insecurity) as well as recent 14-d acute lower respiratory infection (ALRI) and season. METHODS We analyzed 300,133 person-days for 539 children in an observational prospective cohort study to estimate the average effect of biogas stove use on incident diarrhea using cross-validated targeted maximum likelihood estimation (CV-TMLE). RESULTS Households reported using biogas cookstoves in the past 3 d for 23% of observed person-days. The adjusted relative risk of diarrhea for children exposed to biogas cookstove use was 1.31 (95% confidence interval (CI): 1.00, 1.71) compared to unexposed children. The estimated effect of biogas stove use on diarrhea was stronger among breastfed children (2.09; 95% CI: 1.35, 3.25) than for nonbreastfed children and stronger during the dry season (2.03; 95% CI: 1.17, 3.53) than in the wet season. Among children exposed to biogas cookstove use, those with a recent ALRI had the highest mean risk of diarrhea, estimated at 4.53 events (95% CI: 1.03, 8.04) per 1,000 person-days. DISCUSSION This analysis provides new evidence that child diarrhea may be an unintended health risk of biogas cookstove use. Additional studies are needed to identify exposure pathways of fecal pathogen contamination associated with biodigesters to improve the safety of these widely distributed public health interventions. https://doi.org/10.1289/EHP9468.
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Affiliation(s)
- Heather K. Amato
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, California, USA
| | - Caitlin Hemlock
- Division of Epidemiology, University of California, Berkeley School of Public Health, Berkeley, California, USA
| | - Kristin L. Andrejko
- Division of Epidemiology, University of California, Berkeley School of Public Health, Berkeley, California, USA
| | - Anna R. Smith
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, California, USA
| | - Nima S. Hejazi
- Division of Biostatistics, University of California, Berkeley School of Public Health, Berkeley, California, USA
| | - Alan E. Hubbard
- Division of Biostatistics, University of California, Berkeley School of Public Health, Berkeley, California, USA
| | | | - Ramesh K. Adhikari
- Tribhuvan University, Institute of Medicine, Maharajgunj Medical Campus, Kathmandu, Nepal
| | - Dhiraj Pokhrel
- Society for Legal and Environmental Analysis and Development Research (LEADERS), Nepal
| | - Kirk Smith
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, California, USA
| | - Jay P. Graham
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, California, USA
| | - Amod Pokhrel
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, California, USA
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Espira L, Aung T, Han K, Jagger P, Eisenberg JNS. Determinants of Pathogen Contamination of the Environment in the Greater Yangon Area, Myanmar. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16465-16476. [PMID: 34792323 DOI: 10.1021/acs.est.1c02887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recent results from water, sanitation, and hygiene interventions highlight the need to better understand environmental influences on enteropathogen transmission. We quantified a range of viral, bacterial, and protozoal pathogens and one indicator, Enterococcus faecalis in soil and water from urban and rural sites in and around Yangon, Myanmar. We found that environmental characteristics associated with contamination differed by pathogens and substrates. In soil, bacterial pathogen gene counts were associated with elevation and drainage ditches (compared to stagnant water) (RR = 0.96, 95% CI 0.93, 0.99 and RR = 1.70, 95% CI 1.18, 2.45, respectively), while viral gene counts were associated with the presence of sanitation facilities within 50 m of the collection point (RR = 3.99, 95% CI 1.12, 14.24). In water, E. faecalis, total pathogen, and bacterial pathogen gene counts were associated with drainage ditches (RR = 1.86, 95% CI 1.27, 2.72, RR = 1.38 95% CI 1.09, 1.74, and RR = 1.38 95% CI 1.07, 1.77, respectively). E. faecalis, total pathogen, bacterial pathogen, and viral gene counts were associated with the presence of uncollected garbage within 50 m of the collection point (RR = 1.57, 95% CI 1.00, 2.47, RR = 1.52, 95% CI 1.16, 2.00, RR = 1.52, 95% CI 1.13, 2.06, and RR = 1.75, 95% CI 1.17, 2.61 respectively). Measuring the environment provides added specificity toward identifying important environmental pathways that require mitigation.
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Affiliation(s)
- Leon Espira
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ther Aung
- Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27516, United States
| | - Khin Han
- Department of Geography, West Yangon University, Yangon 13393, Myanmar
| | - Pamela Jagger
- School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Joseph N S Eisenberg
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan 48109, United States
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Holcomb DA, Knee J, Capone D, Sumner T, Adriano Z, Nalá R, Cumming O, Brown J, Stewart JR. Impacts of an Urban Sanitation Intervention on Fecal Indicators and the Prevalence of Human Fecal Contamination in Mozambique. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:11667-11679. [PMID: 34382777 PMCID: PMC8429117 DOI: 10.1021/acs.est.1c01538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fecal source tracking (FST) may be useful to assess pathways of fecal contamination in domestic environments and to estimate the impacts of water, sanitation, and hygiene (WASH) interventions in low-income settings. We measured two nonspecific and two human-associated fecal indicators in water, soil, and surfaces before and after a shared latrine intervention from low-income households in Maputo, Mozambique, participating in the Maputo Sanitation (MapSan) trial. Up to a quarter of households were impacted by human fecal contamination, but trends were unaffected by improvements to shared sanitation facilities. The intervention reduced Escherichia coli gene concentrations in soil but did not impact culturable E. coli or the prevalence of human FST markers in a difference-in-differences analysis. Using a novel Bayesian hierarchical modeling approach to account for human marker diagnostic sensitivity and specificity, we revealed a high amount of uncertainty associated with human FST measurements and intervention effect estimates. The field of microbial source tracking would benefit from adding measures of diagnostic accuracy to better interpret findings, particularly when FST analyses convey insufficient information for robust inference. With improved measures, FST could help identify dominant pathways of human and animal fecal contamination in communities and guide the implementation of effective interventions to safeguard health.
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Affiliation(s)
- David A. Holcomb
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States of America
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States of America
| | - Jackie Knee
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States of America
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Drew Capone
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States of America
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States of America
| | - Trent Sumner
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States of America
| | | | - Rassul Nalá
- Instituto Nacional de Saúde, Ministério da Saúde, Maputo, Mozambique
| | - Oliver Cumming
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Joe Brown
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States of America
| | - Jill R. Stewart
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States of America
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Capone D, Berendes D, Cumming O, Holcomb D, Knee J, Konstantinidis KT, Levy K, Nalá R, Risk BB, Stewart J, Brown J. Impact of an Urban Sanitation Intervention on Enteric Pathogen Detection in Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9989-10000. [PMID: 34236178 PMCID: PMC8327413 DOI: 10.1021/acs.est.1c02168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Environmental fecal contamination is common in many low-income cities, contributing to a high burden of enteric infections and associated negative sequelae. To evaluate the impact of a shared onsite sanitation intervention in Maputo, Mozambique on enteric pathogens in the domestic environment, we collected 179 soil samples at shared latrine entrances from intervention (n = 49) and control (n = 51) compounds during baseline (preintervention) and after 24 months (postintervention) as part of the Maputo Sanitation Trial. We tested soils for the presence of nucleic acids associated with 18 enteric pathogens using a multiplex reverse transcription qPCR platform. We detected at least one pathogen-associated gene target in 91% (163/179) of soils and a median of 3 (IQR = 1, 5) pathogens. Using a difference-in-difference analysis and adjusting for compound population, visibly wet soil, sun exposure, wealth, temperature, animal presence, and visible feces, we estimate the intervention reduced the probability of detecting ≥1 pathogen gene by 15% (adjusted prevalence ratio, aPR = 0.85; 95% CI: 0.70, 1.0) and the total number of pathogens by 35% (aPR = 0.65; 0.44, 0.95) in soil 24 months following the intervention. These results suggest that the intervention reduced the presence of some fecal contamination in the domestic environment, but pathogen detection remained prevalent 24 months following the introduction of new latrines.
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Affiliation(s)
- Drew Capone
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - David Berendes
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Oliver Cumming
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David Holcomb
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jackie Knee
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Konstantinos T. Konstantinidis
- Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia, United States of America
| | - Karen Levy
- Environmental and Occupational Health Sciences, University of Washington, 2980 15th Ave NE, Seattle, Washington, United States of America
| | - Rassul Nalá
- Ministério da Saúde, Instituto Nacional de Saúde Maputo, Maputo, Mozambique
| | - Benjamin B. Risk
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, Georgia, United States of America
| | - Jill Stewart
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Joe Brown
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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Kwong LH, Sen D, Islam S, Shahriar S, Benjamin-Chung J, Arnold BF, Hubbard A, Parvez SM, Islam M, Unicomb L, Rahman MM, Nelson K, Colford JM, Luby SP, Ercumen A. Effect of sanitation improvements on soil-transmitted helminth eggs in courtyard soil from rural Bangladesh: Evidence from a cluster-randomized controlled trial. PLoS Negl Trop Dis 2021; 15:e0008815. [PMID: 34319986 PMCID: PMC8351931 DOI: 10.1371/journal.pntd.0008815] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 08/09/2021] [Accepted: 06/24/2021] [Indexed: 11/19/2022] Open
Abstract
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. Trial Registration: NCT01590095.
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Affiliation(s)
- Laura H. Kwong
- Woods Institute for the Environment, Stanford University, Stanford, California, United States of America
| | - Debashis Sen
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Sharmin Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Sunny Shahriar
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Jade Benjamin-Chung
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Benjamin F. Arnold
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, California, United States of America
| | - Alan Hubbard
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Sarker Masud Parvez
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Mahfuza Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Leanne Unicomb
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Md. Mahbubur Rahman
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Kara Nelson
- Department of Civil Engineering, University of California, Berkeley, California, United States of America
| | - John M. Colford
- School of Public Health, University of California, Berkeley, California, United States of America
| | - Stephen P. Luby
- Woods Institute for the Environment, Stanford University, Stanford, California, United States of America
| | - Ayse Ercumen
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, United States of America
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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. Longitudinal Effects of a Sanitation Intervention on Environmental Fecal Contamination in a Cluster-Randomized Controlled Trial in Rural Bangladesh. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8169-8179. [PMID: 34086447 PMCID: PMC8213058 DOI: 10.1021/acs.est.1c01114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 05/06/2023]
Abstract
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.
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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, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka 1212, Bangladesh
| | - Andrew Mertens
- Division
of Epidemiology and Biostatistics, School
of Public Health, University of California, Berkeley, California 94720, United States
| | - Amy J. Pickering
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Laura H. Kwong
- Woods
Institute for the Environment, Stanford
University, Stanford, California 94305, United States
| | - Benjamin F. Arnold
- Francis I.
Proctor Foundation, University of California, San Francisco, California 94143, United States
| | - Jade Benjamin-Chung
- Division
of Epidemiology and Biostatistics, School
of Public Health, University of California, Berkeley, California 94720, United States
| | - Alan E. Hubbard
- Division
of Epidemiology and Biostatistics, School
of Public Health, University of California, Berkeley, California 94720, United States
| | - Mahfuja Alam
- Environmental
Interventions Unit, Infectious Disease Division, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka 1212, Bangladesh
| | - Debashis Sen
- Environmental
Interventions Unit, Infectious Disease Division, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka 1212, Bangladesh
| | - Sharmin Islam
- Environmental
Interventions Unit, Infectious Disease Division, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka 1212, Bangladesh
| | - Mahbubur Rahman
- Environmental
Interventions Unit, Infectious Disease Division, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka 1212, Bangladesh
| | - Leanne Unicomb
- Environmental
Interventions Unit, Infectious Disease Division, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka 1212, Bangladesh
| | - Stephen P. Luby
- Woods
Institute for the Environment, Stanford
University, Stanford, California 94305, United States
| | - John M. Colford
- Division
of Epidemiology and Biostatistics, School
of Public Health, University of California, 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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25
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Kapoor R, Ebdon J, Wadhwa A, Chowdhury G, Wang Y, Raj SJ, Siesel C, Durry SE, Mairinger W, Mukhopadhyay AK, Kanungo S, Dutta S, Moe CL. Evaluation of Low-Cost Phage-Based Microbial Source Tracking Tools for Elucidating Human Fecal Contamination Pathways in Kolkata, India. Front Microbiol 2021; 12:673604. [PMID: 34093494 PMCID: PMC8173070 DOI: 10.3389/fmicb.2021.673604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/15/2021] [Indexed: 11/17/2022] Open
Abstract
Phages, such as those infecting Bacteroides spp., have been proven to be reliable indicators of human fecal contamination in microbial source tracking (MST) studies, and the efficacy of these MST markers found to vary geographically. This study reports the application and evaluation of candidate MST methods (phages infecting previously isolated B. fragilis strain GB-124, newly isolated Bacteroides strains (K10, K29, and K33) and recently isolated Kluyvera intermedia strain ASH-08), along with non-source specific somatic coliphages (SOMCPH infecting strain WG-5) and indicator bacteria (Escherichia coli) for identifying fecal contamination pathways in Kolkata, India. Source specificity of the phage-based methods was first tested using 60 known non-human fecal samples from common animals, before being evaluated with 56 known human samples (municipal sewage) collected during both the rainy and dry season. SOMCPH were present in 40-90% of samples from different animal species and in 100% of sewage samples. Phages infecting Bacteroides strain GB-124 were not detected from the majority (95%) of animal samples (except in three porcine samples) and were present in 93 and 71% of the sewage samples in the rainy and dry season (Mean = 1.42 and 1.83 log10PFU/100mL, respectively), though at lower levels than SOMCPH (Mean = 3.27 and 3.02 log10PFU/100mL, respectively). Phages infecting strain ASH-08 were detected in 89 and 96% of the sewage samples in the rainy and dry season, respectively, but were also present in all animal samples tested (except goats). Strains K10, K29, and K30 were not found to be useful MST markers due to low levels of phages and/or co-presence in non-human sources. GB-124 and SOMCPH were subsequently deployed within two low-income neighborhoods to determine the levels and origin of fecal contamination in 110 environmental samples. E. coli, SOMCPH, and phages of GB-124 were detected in 68, 42, and 28% of the samples, respectively. Analyses of 166 wastewater samples from shared community toilets and 21 samples from sewage pumping stations from the same districts showed that SOMCPH were present in 100% and GB-124 phages in 31% of shared toilet samples (Median = 5.59 and <1 log10 PFU/100 mL, respectively), and both SOMCPH and GB-124 phages were detected in 95% of pumping station samples (Median = 5.82 and 4.04 log10 PFU/100 mL, respectively). Our findings suggest that GB-124 and SOMCPH have utility as low-cost fecal indicator tools which can facilitate environmental surveillance of enteric organisms, elucidate human and non-human fecal exposure pathways, and inform interventions to mitigate exposure to fecal contamination in the residential environment of Kolkata, India.
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Affiliation(s)
- Renuka Kapoor
- Center for Global Safe Water, Sanitation and Hygiene, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - James Ebdon
- Environment and Public Health Research and Enterprise Group (EPHREG), University of Brighton, Brighton, United Kingdom
| | - Ashutosh Wadhwa
- Center for Global Safe Water, Sanitation and Hygiene, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Goutam Chowdhury
- ICMR – National Institute of Cholera and Enteric Diseases (NICED), Kolkata, India
| | - Yuke Wang
- Center for Global Safe Water, Sanitation and Hygiene, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Suraja J. Raj
- Center for Global Safe Water, Sanitation and Hygiene, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Casey Siesel
- Center for Global Safe Water, Sanitation and Hygiene, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Sarah E. Durry
- Center for Global Safe Water, Sanitation and Hygiene, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Wolfgang Mairinger
- Center for Global Safe Water, Sanitation and Hygiene, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | | | - Suman Kanungo
- ICMR – National Institute of Cholera and Enteric Diseases (NICED), Kolkata, India
| | - Shanta Dutta
- ICMR – National Institute of Cholera and Enteric Diseases (NICED), Kolkata, India
| | - Christine L. Moe
- Center for Global Safe Water, Sanitation and Hygiene, Rollins School of Public Health, Emory University, Atlanta, GA, United States
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26
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Knee J, Sumner T, Adriano Z, Anderson C, Bush F, Capone D, Casmo V, Holcomb D, Kolsky P, MacDougall A, Molotkova E, Braga JM, Russo C, Schmidt WP, Stewart J, Zambrana W, Zuin V, Nalá R, Cumming O, Brown J. Effects of an urban sanitation intervention on childhood enteric infection and diarrhea in Maputo, Mozambique: A controlled before-and-after trial. eLife 2021; 10:e62278. [PMID: 33835026 PMCID: PMC8121544 DOI: 10.7554/elife.62278] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 04/03/2021] [Indexed: 12/12/2022] Open
Abstract
We conducted a controlled before-and-after trial to evaluate the impact of an onsite urban sanitation intervention on the prevalence of enteric infection, soil transmitted helminth re-infection, and diarrhea among children in Maputo, Mozambique. A non-governmental organization replaced existing poor-quality latrines with pour-flush toilets with septic tanks serving household clusters. We enrolled children aged 1-48 months at baseline and measured outcomes before and 12 and 24 months after the intervention, with concurrent measurement among children in a comparable control arm. Despite nearly exclusive use, we found no evidence that intervention affected the prevalence of any measured outcome after 12 or 24 months of exposure. Among children born into study sites after intervention, we observed a reduced prevalence of Trichuris and Shigella infection relative to the same age group at baseline (<2 years old). Protection from birth may be important to reduce exposure to and infection with enteric pathogens in this setting.
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Affiliation(s)
- Jackie Knee
- London School of Hygiene & Tropical Medicine, Faculty of Infectious Tropical Diseases, Disease Control DepartmentLondonUnited Kingdom
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | - Trent Sumner
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | | | - Claire Anderson
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | - Farran Bush
- Georgia Institute of Technology, School of Chemical and Biomolecular EngineeringAtlantaUnited States
| | - Drew Capone
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
| | | | - David Holcomb
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of Environmental Sciences and EngineeringChapel HillUnited States
| | - Pete Kolsky
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
| | - Amy MacDougall
- London School of Hygiene & Tropical Medicine, Faculty of Epidemiology and Population Health, Department of Medical StatisticsLondonUnited Kingdom
| | - Evgeniya Molotkova
- Georgia Institute of Technology, School of Biological SciencesAtlantaUnited States
| | | | - Celina Russo
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | - Wolf Peter Schmidt
- London School of Hygiene & Tropical Medicine, Faculty of Infectious Tropical Diseases, Disease Control DepartmentLondonUnited Kingdom
| | - Jill Stewart
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
| | - Winnie Zambrana
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
| | - Valentina Zuin
- Yale-NUS College, Division of Social ScienceSingaporeSingapore
| | | | - Oliver Cumming
- London School of Hygiene & Tropical Medicine, Faculty of Infectious Tropical Diseases, Disease Control DepartmentLondonUnited Kingdom
| | - Joe Brown
- Georgia Institute of Technology, School of Civil and Environmental EngineeringAtlantaUnited States
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of EpidemiologyChapel HillUnited States
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27
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Capone D, Bivins A, Knee J, Cumming O, Nalá R, Brown J. Quantitative Microbial Risk Assessment of Pediatric Infections Attributable to Ingestion of Fecally Contaminated Domestic Soils in Low-Income Urban Maputo, Mozambique. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1941-1952. [PMID: 33472364 PMCID: PMC7860170 DOI: 10.1021/acs.est.0c06972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 05/03/2023]
Abstract
Rigorous studies of water, sanitation, and hygiene interventions in low- and middle-income countries (LMICs) suggest that children are exposed to enteric pathogens via multiple interacting pathways, including soil ingestion. In 30 compounds (household clusters) in low-income urban Maputo, Mozambique, we cultured Escherichia coli and quantified gene targets from soils (E. coli: ybbW, Shigella/enteroinvasive E. coli (EIEC): ipaH, Giardia duodenalis: β-giardin) using droplet digital PCR at three compound locations (latrine entrance, solid waste area, dishwashing area). We found that 88% of samples were positive for culturable E. coli (mean = 3.2 log10 CFUs per gram of dry soil), 100% for molecular E. coli (mean = 5.9 log10 gene copies per gram of dry soil), 44% for ipaH (mean = 2.5 log10), and 41% for β-giardin (mean = 2.1 log10). Performing stochastic quantitative microbial risk assessment using soil ingestion parameters from an LMIC setting for children 12-23 months old, we estimated that the median annual infection risk by G. duodenalis was 7100-fold (71% annual infection risk) and by Shigella/EIEC was 4000-fold (40% annual infection risk) greater than the EPA's standard for drinking water. Compounds in Maputo, and similar settings, require contact and source control strategies to reduce the ingestion of contaminated soil and achieve acceptable levels of risk.
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Affiliation(s)
- Drew Capone
- Civil
and Environmental Engineering, Georgia Institute
of Technology, Atlanta, Georgia 30332, United States
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Aaron Bivins
- Department
of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jackie Knee
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, London WC1E 7HT, U.K.
| | - Oliver Cumming
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, London WC1E 7HT, U.K.
| | - Rassul Nalá
- Ministério
da Saúde, Instituto Nacional de Saúde Maputo, Maputo 1100, Mozambique
| | - Joe Brown
- Civil
and Environmental Engineering, Georgia Institute
of Technology, Atlanta, Georgia 30332, United States
- Department
of Environmental Sciences and Engineering, Gillings School of Public
Health, University of North Carolina at
Chapel Hill, Chapel Hill, North Carolina 27599, United States
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28
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Fuhrmeister ER, Ercumen A, Grembi JA, Islam M, Pickering AJ, Nelson KL. Shared bacterial communities between soil, stored drinking water, and hands in rural Bangladeshi households. WATER RESEARCH X 2020; 9:100056. [PMID: 32529181 PMCID: PMC7276488 DOI: 10.1016/j.wroa.2020.100056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/19/2020] [Accepted: 05/21/2020] [Indexed: 05/24/2023]
Abstract
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.
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Affiliation(s)
- Erica R. Fuhrmeister
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, United States
| | - Ayse Ercumen
- School of Public Health, University of California, Berkeley, CA, 94720, United States
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27607, United States
| | - Jessica A. Grembi
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, 94305, United States
| | - Mahfuza Islam
- Environmental Intervention Unit, Infectious Disease Division, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka, 1212, Bangladesh
| | - Amy J. Pickering
- Civil and Environmental Engineering, Tufts University, Medford, MA, 02153, United States
| | - Kara L. Nelson
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, United States
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29
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Kwong LH, Ercumen A, Pickering AJ, Arsenault JE, Islam M, Parvez SM, Unicomb L, Rahman M, Davis J, Luby SP. 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). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13828-13838. [PMID: 33078615 PMCID: PMC7643345 DOI: 10.1021/acs.est.0c02606] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
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.
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Affiliation(s)
- Laura H. Kwong
- Woods
Institute for the Environment, Stanford
University, Stanford, California 94305, United States
| | - Ayse Ercumen
- Department
of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Amy J. Pickering
- Department
of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Joanne E. Arsenault
- Program
in International Community Nutrition, University
of California, Davis, California 95616, United States
| | - Mahfuza Islam
- International
Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka 1000, Bangladesh
| | - Sarker M Parvez
- International
Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka 1000, Bangladesh
| | - Leanne Unicomb
- International
Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka 1000, Bangladesh
| | - Mahbubur Rahman
- International
Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka 1000, Bangladesh
| | - Jennifer Davis
- Woods
Institute for the Environment, Stanford
University, Stanford, California 94305, United States
- Department
of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Stephen P. Luby
- Woods
Institute for the Environment, Stanford
University, Stanford, California 94305, United States
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