Putting the “A” into WaSH: a call for integrated management of water, animals, sanitation, and hygiene

Abstract

Water, sanitation, and hygiene (WaSH) are foundational public health interventions for infectious disease control. Renewed efforts to end open defecation and provide universal access to safe drinking water, sanitation, and hygiene by 2030 are being enacted through the Sustainable Development Goals. However, results from clinical trials1Luby SP Rahman M Arnold BF et al.Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Bangladesh: a cluster randomised controlled trial.Lancet Glob Health. 2018; 6: e302-e315Summary Full Text Full Text PDF PubMed Scopus (315) Google Scholar, 2Null C Stewart CP Pickering AJ et al.Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Kenya: a cluster-randomised controlled trial.Lancet Glob Health. 2018; 6: e316-e329Summary Full Text Full Text PDF PubMed Scopus (290) Google Scholar, 3Humphrey JH Mbuya MNN Ntozini R et al.Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.Lancet Glob Health. 2019; 7: e132-e147Summary Full Text Full Text PDF PubMed Scopus (198) Google Scholar question the efficacy of conventional rural WaSH approaches in low-income and middle-income countries (LMICs). Randomised trials in Bangladesh,1Luby SP Rahman M Arnold BF et al.Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Bangladesh: a cluster randomised controlled trial.Lancet Glob Health. 2018; 6: e302-e315Summary Full Text Full Text PDF PubMed Scopus (315) Google Scholar Kenya,2Null C Stewart CP Pickering AJ et al.Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Kenya: a cluster-randomised controlled trial.Lancet Glob Health. 2018; 6: e316-e329Summary Full Text Full Text PDF PubMed Scopus (290) Google Scholar and Zimbabwe,3Humphrey JH Mbuya MNN Ntozini R et al.Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.Lancet Glob Health. 2019; 7: e132-e147Summary Full Text Full Text PDF PubMed Scopus (198) Google Scholar which introduced household pit latrines, hand-washing with soap, and point-of-use water chlorination, found no effect on child growth, and two of the three trials found no reductions in diarrhoea in children. We have, therefore, called for transformative WaSH approaches,4Pickering AJ Null C Winch PJ et al.The WASH Benefits and SHINE trials: interpretation of WASH intervention effects on linear growth and diarrhoea.Lancet Glob Health. 2019; 7: e1139-e1146Summary Full Text Full Text PDF PubMed Scopus (135) Google Scholar to more effectively reduce pathogen burden and promote child health and growth in LMICs. However, currently, it remains uncertain what transformative WaSH entails. We hypothesise that exposure to animal faeces is currently an under-recognised threat to human health. Estimates published in 2018 have highlighted the scale of animal faecal hazards,5Berendes DM Yang PJ Lai A Hu D Brown J Estimation of global recoverable human and animal faecal biomass.Nat Sustain. 2018; 1: 679-685Crossref Scopus (42) Google Scholar which are not explicitly addressed by conventional WaSH strategies. Globally, 80% of the faecal load is estimated to come from livestock animals, including two-thirds of faeces at the household level.5Berendes DM Yang PJ Lai A Hu D Brown J Estimation of global recoverable human and animal faecal biomass.Nat Sustain. 2018; 1: 679-685Crossref Scopus (42) Google Scholar Research addressing the effect of domestic and wild animal faeces on WaSH effectiveness is scarce6Matilla F Velleman Y Harrison W Nevel M Animal influence on water, sanitation and hygiene measures for zoonosis control at the household level: a systematic literature review.PLoS Negl Trop Dis. 2018; 12e006619Crossref Scopus (13) Google Scholar, 7Penakalapati G Swarthout J Delahoy MJ et al.Exposure to animal feces and human health: a systematic review and proposed research priorities.Environ Sci Technol. 2017; 51: 11537-11552Crossref PubMed Scopus (132) Google Scholar and collaboration between the WaSH, public health, and animal health sectors in LMICs insufficient.6Matilla F Velleman Y Harrison W Nevel M Animal influence on water, sanitation and hygiene measures for zoonosis control at the household level: a systematic literature review.PLoS Negl Trop Dis. 2018; 12e006619Crossref Scopus (13) Google Scholar As an interdisciplinary group of researchers, policy makers, and practitioners in One Health, epidemiology, veterinary medicine, child health, nutrition, microbiology, geography, social science, WaSH, and animal ecology, we met (on May 22–23, 2019) to focus attention on the neglected burden of domestic and wild animal faecal exposure among rural households in LMICs. We contend that without adding safe management of animal faeces to current programmes focused solely on human waste, rural WaSH programmes will insufficiently reduce faecal exposure from all sources to the extent needed to improve child health. To emphasise this, we propose a paradigm shift in WaSH terminology, by upgrading the currently diminutive and redundant “a” to “A”—Water, Animals, Sanitation, and Hygiene—highlighting that reducing exposure to animals and their faeces also needs to be central to WASH approaches. Current programmes focus on containment of human faeces and so do not avert two-thirds of potential faecal hazards,5Berendes DM Yang PJ Lai A Hu D Brown J Estimation of global recoverable human and animal faecal biomass.Nat Sustain. 2018; 1: 679-685Crossref Scopus (42) Google Scholar meaning they are unlikely to achieve the large-scale reductions in microbial exposure that we believe are necessary.4Pickering AJ Null C Winch PJ et al.The WASH Benefits and SHINE trials: interpretation of WASH intervention effects on linear growth and diarrhoea.Lancet Glob Health. 2019; 7: e1139-e1146Summary Full Text Full Text PDF PubMed Scopus (135) Google Scholar There are many unknowns in how to best maximise the benefits and minimise the risks of animal ownership.7Penakalapati G Swarthout J Delahoy MJ et al.Exposure to animal feces and human health: a systematic review and proposed research priorities.Environ Sci Technol. 2017; 51: 11537-11552Crossref PubMed Scopus (132) Google Scholar Livestock are crucial to rural livelihoods, contributing to household economic and sociocultural wellbeing, and providing animal-source foods, transport, and manure for fertiliser and fuel. However, the message that animal faeces should be considered potentially hazardous, just as human faeces are, needs to be central to WASH programming, with safe management of animal faeces added to the global WASH agenda. Although some trials have attempted to reduce zoonotic transmission of enteropathogens by providing tools to separate livestock from children,3Humphrey JH Mbuya MNN Ntozini R et al.Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.Lancet Glob Health. 2019; 7: e132-e147Summary Full Text Full Text PDF PubMed Scopus (198) Google Scholar, 8The US Government's Global Hunger & Food Security InitiativeCaged: Campylobacter genomics and environmental enteric dysfunction.http://livestocklab.ifas.ufl.edu/projects/caged-project/Date: 2019Date accessed: July 31, 2019Google Scholar, 9Gelli A Becquey E Ganaba R et al.Improving diets and nutrition through an integrated poultry value chain and nutrition intervention (SELEVER) in Burkina Faso: a study protocol for a randomized trial.Trials. 2017; 18: 412Crossref PubMed Scopus (24) Google Scholar this approach is not always feasible, financially viable (eg, penned chickens require feeding), beneficial to animal health and welfare, or viewed favourably by local community members. Instead, we argue for a more holistic One Health approach to WASH, which considers the interconnection between the health of people, animals, and our shared environment. A One Health approach encourages collaboration across multiple disciplines and sectors with the ultimate goal of achieving optimal health outcomes for all, rather than a singular focus on human health as the endpoint. This approach would provide an opportunity to devise and test integrated programmes that are mindful of the numerous competing and interdependent priorities for households, while considering livestock production, welfare, and social value; soil health and crop yields; and water and air quality, in addition to human health. Indeed, such a comprehensive approach might yield greater gains to all sectors than individually focused projects alone. Negative trial results,1Luby SP Rahman M Arnold BF et al.Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Bangladesh: a cluster randomised controlled trial.Lancet Glob Health. 2018; 6: e302-e315Summary Full Text Full Text PDF PubMed Scopus (315) Google Scholar, 2Null C Stewart CP Pickering AJ et al.Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Kenya: a cluster-randomised controlled trial.Lancet Glob Health. 2018; 6: e316-e329Summary Full Text Full Text PDF PubMed Scopus (290) Google Scholar, 3Humphrey JH Mbuya MNN Ntozini R et al.Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.Lancet Glob Health. 2019; 7: e132-e147Summary Full Text Full Text PDF PubMed Scopus (198) Google Scholar published in 2018 and 2019, from conventional WaSH interventions indicate that it has never been more important to seek transformative, community-driven, integrated approaches.4Pickering AJ Null C Winch PJ et al.The WASH Benefits and SHINE trials: interpretation of WASH intervention effects on linear growth and diarrhoea.Lancet Glob Health. 2019; 7: e1139-e1146Summary Full Text Full Text PDF PubMed Scopus (135) Google Scholar The first step—putting the “A” into WASH—is to shift the thinking to accelerate progress towards transformative WASH by considering pathways of enteropathogen transmission that are not currently central to WaSH strategies. We believe more substantial reductions in household and environmental faecal contamination are possible through concerted efforts to collectively improve the health of animals, humans, and the environment, while maintaining the benefits of livestock ownership. There is a pressing need to test new intervention approaches that will tackle all household faecal exposure through a combined focus on Water, Animals, Sanitation, and Hygiene to yield greater gains from WASH. We declare no competing interests. We thank Shamiso Fernando, Virginia Sauramba, and Philipa Rambanepasi for their contributions to the meeting that led to this manuscript in Harare, Zimbabwe, on May 22–23, 2019. The meeting was funded by the UK Medical Research Council (grant MC_PC_MR/R019436/1 ). AJP, RCR, and CE are funded by the Wellcome Trust (grants 108065/Z/15/Z , 206455/Z/17/Z , and 203905/Z/16/Z ). The opinions in this Comment are those of the authors and do not necessarily reflect the views of their institutions, UNICEF, or UN.