Success in vaccination programming through community health workers: a qualitative analysis of interviews and focus group discussions from Nepal, Senegal and Zambia.

OBJECTIVES: Community health workers are essential to front-line health outreach throughout low-income and middle-income countries, including programming for early childhood immunisation. Understanding how community health workers are engaged for successful early childhood vaccination among countries who showed success in immunisation coverage would support evidence-based policy guidance across contexts. DESIGN: We employed a multiple case study design using qualitative research methods. SETTING: We conducted research in Nepal, Senegal and Zambia. PARTICIPANTS: We conducted 207 interviews and 71 focus group discussions with 678 participants at the national, regional, district, health facility and community levels of the health systems of Nepal, Senegal and Zambia, from October 2019 to April 2021. We used thematic analysis to investigate contributing factors of community health worker programming that supported early childhood immunisation within each country and across contexts. RESULTS: Implementation of vaccination programming relied principally on the (1) organisation, (2) motivation and (3) trust of community health workers. Organisation was accomplished by expanding cadres of community health workers to carry out their roles and responsibilities related to vaccination. Motivation was supported by intrinsic and extrinsic incentives. Trust was expressed by communities due to community health worker respect and value placed on their work. CONCLUSION: Improvements in immunisation coverage was facilitated by community health worker organisation, motivation and trust. With the continued projection of health worker shortages, especially in low-income countries, community health workers bridged the equity gap in access to vaccination services by enabling wider reach to underserved populations. Although improvements in vaccination programming were seen in all three countries-including government commitment to addressing human resource deficits, training and remuneration; workload, inconsistency in compensation, training duration and scope, and supervision remain major challenges to immunisation programming. Health decision-makers should consider organisation, motivation and trust of community health workers to improve the implementation of immunisation programming.

The state of reporting context and implementation in peer-reviewed evaluations of water, sanitation, and hygiene interventions: A scoping review.

INTRODUCTION: To accurately assess evidence from environmental and public health field trials, context and implementation details of the intervention must be weighed with trial results; yet these details are under and inconsistently reported for water, sanitation, and hygiene (WASH), limiting the external validity of the evidence. METHODS: To quantify the level of reporting of context and implementation in WASH evaluations, we conducted a scoping review of the 40 most cited evaluations of WASH interventions published in the last 10 years (2012-2022). We applied criteria derived from a review of existing reporting guidance from other sectors including healthcare and implementation science. We subsequently reviewed main articles, supplements, protocols, and other associated resources to assess thoroughness of context and implementation reporting. RESULTS: Of the final 25 reporting items we searched for, four-intervention name, approach, location, and temporality-were reported by all studies. Five items-theory, implementer qualifications, dose intensity, targeting, and measured fidelity-were not reported in over a third of reviewed articles. Only two studies (5%) reported all items in our checklist. Only 74% of items were found in the main article, while the rest were found in separate papers (7%) or not at all (19%). DISCUSSION: Inconsistent reporting of WASH implementation illustrates a major challenge in the sector. It is difficult to know what interventions are actually being evaluated and how to compare evaluation results. This inconsistent and incomplete implementation reporting limits the ability of programmers and policy makers to apply the available evidence to their contexts. Standardized reporting guidelines would improve the application of the evidence for WASH field evaluations.

Quantifying Enteropathogen Contamination along Chicken Value Chains in Maputo, Mozambique: A Multidisciplinary and Mixed-Methods Approach to Identifying High Exposure Settings.

BACKGROUND: Small-scale poultry production is widespread and increasing in low- and middle-income countries (LMICs). Exposure to enteropathogens in poultry feces increases the hazard of human infection and related sequela, and the burden of disease due to enteric infection in children <5 y in particular is substantial. Yet, the containment and management of poultry-associated fecal waste in informal settings in LMICs is largely unregulated. OBJECTIVES: To improve the understanding of potential exposures to enteropathogens carried by chickens, we used mixed methods to map and quantify microbial hazards along production value chains among broiler, layer, and indigenous chickens in Maputo, Mozambique. METHODS: To map and describe the value chains, we conducted 77 interviews with key informants working in locations where chickens and related products are sold, raised, and butchered. To quantify microbial hazards, we collected chicken carcasses (n=75) and fecal samples (n=136) from chickens along the value chain and assayed them by qPCR for the chicken-associated bacterial enteropathogens C. jejuni/coli and Salmonella spp. RESULTS: We identified critical hazard points along the chicken value chains and identified management and food hygiene practices that contribute to potential exposures to chicken-sourced enteropathogens. We detected C. jejuni/coli in 84 (76%) of fecal samples and 52 (84%) of carcass rinses and Salmonella spp. in 13 (11%) of fecal samples and 16 (21%) of carcass rinses. Prevalence and level of contamination increased as chickens progressed along the value chain, from no contamination of broiler chicken feces at the start of the value chain to 100% contamination of carcasses with C. jejuni/coli at informal markets. Few hazard mitigation strategies were found in the informal sector. DISCUSSION: High prevalence and concentration of C. jejuni/coli and Salmonella spp. contamination along chicken value chains suggests a high potential for exposure to these enteropathogens associated with chicken production and marketing processes in the informal sector in our study setting. We identified critical control points, such as the carcass rinse step and storage of raw chicken meat, that could be intervened in to mitigate risk, but regulation and enforcement pose challenges. This mixed-methods approach can also provide a model to understand animal value chains, sanitary risks, and associated exposures in other settings. https://doi.org/10.1289/EHP11761.

Synthesising the evidence for effective hand hygiene in community settings: an integrated protocol for multiple related systematic reviews.

INTRODUCTION: Despite evidence for the efficacy and effectiveness of hand hygiene in reducing the transmission of infectious diseases, there are gaps in global normative guidance around hand hygiene in community settings. The goal of this review is to systematically retrieve and synthesise available evidence on hand hygiene in community settings across four areas: (1) effective hand hygiene; (2) minimum requirements; (3) behaviour change and (4) government measures. METHODS AND ANALYSIS: This protocol entails a two-phased approach to identify relevant studies for multiple related systematic reviews. Phase 1 involves a broad search to capture all studies on hand hygiene in community settings. Databases, trial registries, expert consultations and hand searches of reference lists will be used to ensure an exhaustive search. A comprehensive, electronic search strategy will be used to identify studies indexed in PubMed, Web of Science, EMBASE, CINAHL, Global Health, Cochrane Library, Global Index Medicus, Scopus, PAIS Index, WHO IRIS, UN Digital Library and World Bank eLibrary published in English from January 1980 to March 2023. The outcome of phase 1 will be a reduced sample of studies from which further screening, specific to research questions across the four key areas can be performed. Two reviewers will independently assess each study for inclusion and disagreements will be resolved by a third reviewer. Quantitative and qualitative data will be extracted following best practices. We will assess all studies using the Mixed Method Appraisal Tool. All effect measures pertaining to review outcomes will be reported and a narrative synthesis of all studies will be presented including 'data-driven' descriptive themes and 'theory-driven' analytical themes as applicable. ETHICS AND DISSEMINATION: This systematic review is exempt from ethics approval because the work is carried out on published documents. The findings of the reviews will be disseminated in related peer-reviewed journals. PROSPERO REGISTRATION NUMBER: CRD42023429145.

Opportunities to Interrupt Transmission of Enteropathogens of Poultry Origin in Maputo, Mozambique: A Transmission Model Analysis.

BACKGROUND: The burden of diarrheal diseases remains high among children in low-income countries. Enteropathogens are challenging to control because they are transmitted via multiple pathways. Chickens are an important animal protein source, but live chickens and their products are often highly contaminated with enteropathogens. OBJECTIVES: We conducted this study to a) understand the contribution of multiple transmission pathways to the force of infection of Campylobacter spp. and nontyphoidal Salmonella spp., b) quantify the potential impact of reducing each pathway on human infection, and c) quantify hypothesized pathway reduction from the context of Maputo, Mozambique. METHODS: We developed transmission models for Campylobacter and Salmonella that captured person-to-person, water-to-person, food-to-person, soil-to-person, animal-to-person, and all-other-sources-to-person in an urban, low-income setting in Mozambique. We calibrated these models using prevalence data from Maputo, Mozambique and estimates of attributable fraction of transmission pathways for the region. We simulated the prevalence of human infection after reducing transmission through each pathway. RESULTS: Simulation results indicated that if foodborne transmission were reduced by 90%, the prevalence of Campylobacter and Salmonella infection would decline by [52.2%; 95% credible interval (CrI): 39.7, 63.8] and (46.9%; 95% CrI: 39, 55.4), respectively. Interruption of any other pathway did not have a substantial impact. Combined with survey and microbiology data, if contamination of broiler chicken meat at informal markets in Maputo could be reduced by 90%, the total infection of Campylobacter and Salmonella could be reduced by 21% (16-26%) and 12% (10-13%), respectively. DISCUSSION: Our transmission models showed that the foodborne transmission has to be reduced to control enteropathogen infections in our study site, and likely in other similar contexts, but mitigation of this transmission pathway has not received sufficient attention. Our model can serve as a tool to identify effective mitigation opportunities to control zoonotic enteropathogens. https://doi.org/10.1289/EHP12314.

Symptomatic and asymptomatic enteric protozoan parasitic infection and their association with subsequent growth parameters in under five children in South Asia and sub-Saharan Africa.

BACKGROUND: Entamoeba histolytica, Giardia, and Cryptosporidium are common intestinal protozoan parasites that contribute to a high burden of childhood morbidity and mortality. Our study quantified the association between intestinal protozoan parasites and child anthropometric outcomes among children under-5. METHODS: We analyzed data from 7,800 children enrolled in the Global Enteric Multicenter Study (GEMS) across seven study sites that were positive for intestinal protozoan parasites between December 2007 and March 2011. Parasites were assessed using stool immunoassays (ELISA). We applied multiple linear regression to test the association between any or concurrent parasite and child anthropometric outcomes: length/height-for-age (HAZ), weight-for-age (WAZ), and weight-for-length/height (WHZ) z-score after 60 days of enrollment. Models were stratified by diarrheal symptoms, driven by the study design, and adjusted for potential covariates. FINDINGS: During the follow-up at day 60 after enrollment, child anthropometric outcomes, among the asymptomatic children showed, negative associations between Giardia with HAZ [ß: -0.13; 95% CI: -0.17, -0.09; p<0.001] and WAZ [ß -0.07; 95% CI: -0.11, -0.04; p<0.001], but not WHZ [ß: -0.02; 95% CI:-0.06, 0.02; p = 0.36]; Cryptosporidium with WAZ [ß: -0.15; 95% CI: -0.22, -0.09; p<0.001] and WHZ [ß: -0.18; 95%CI: -0.25, -0.12; p<0.001], but not with HAZ [ß: -0.03; 95% CI: -0.09, 0.04; p = 0.40]. For symptomatic children, no associations were found between Giardia and anthropometry; negative associations were found between Cryptosporidium with HAZ [ß: -0.17; 95% CI: -0.23, -0.11; p<0.001], WAZ [ß: -0.25; 95% CI: -0.31, -0.19; p<0.001] and WHZ [ß: -0.23; 95% CI: -0.30, -0.17; p<0.001]. Among the asymptomatic 24-59 months children, Giardia had a negative association with HAZ [ß: -0.09; 95% CI: -0.15, -0.04; p = 0.001]. No significant associations were found between E. histolytica with child growth. CONCLUSIONS: While some studies have found that Giardia is not associated with (or protective against) acute diarrhea, our findings suggest that it is associated with growth shortfall. This observation underscores the need for preventive strategies targeting enteric protozoan parasites among young children, to reduce the burden of childhood malnutrition.

Critical success factors for high routine immunisation performance: a qualitative analysis of interviews and focus groups from Nepal, Senegal, and Zambia.

OBJECTIVES: Vaccination averts an estimated 2-3 million deaths annually. Although vaccine coverage improvements across Africa and South Asia have remained below global targets, several countries have outperformed their peers with significant increases in coverage. The objective of this study was to examine these countries' vaccination programmes and to identify and describe critical success factors that may have supported these improvements. DESIGN: Multiple case study design using qualitative research methods. SETTING: Three countries with high routine immunisation rates: Nepal, Senegal, and Zambia. PARTICIPANTS: We conducted 207 key informant interviews and 71 focus group discussions with a total of 678 participants. Participants were recruited from all levels, including government officials, health facility staff, frontline workers, community health workers, and parents. Participants were recruited from both urban and rural districts in Nepal, Senegal, and Zambia. RESULTS: Our data revealed that the critical success factors for vaccination programmes relied on the cultural, historical, and statutory context in which the interventions were delivered. In Nepal, Senegal, and Zambia, high immunisation coverage was driven by (1) strong governance structures and healthy policy environments; (2) adjacent successes in health system strengthening; (3) government-led community engagement initiatives, and (4) adaptation considering contextual factors at all levels of the health system. CONCLUSIONS: Throughout this project, our analysis returned to the importance of defining and understanding the context, governance, financing, and health systems within a country, rather than focusing on any one intervention. This paper augments findings from existing literature by highlighting how contextual factors impact implementation decisions that have led to improvements in childhood vaccine delivery. Findings from this research may help identify transferable lessons and support actionable recommendations to improve national immunisation coverage in other settings.

Factors associated with vaccine coverage improvements in Senegal between 2005 and 2019: a quantitative retrospective analysis.

OBJECTIVE: Senegal has demonstrated catalytic improvements in national coverage rates for early childhood vaccination, despite lower development assistance for childhood vaccines in Senegal compared with other low-income and lower-middle income countries. Understanding factors associated with historical changes in childhood vaccine coverage in Senegal, as well as heterogeneities across its 14 regions, can highlight effective practices that might be adapted to improve vaccine coverage elsewhere. DESIGN: Childhood vaccination coverage rates, demographic information and health system characteristics were identified from Senegal's Demographic and Health Surveys (DHS) and Senegal national reports for years 2005-2019. Multivariate logistic and linear regression analyses were performed to determine statistical associations of demographic and health system characteristics with respect to childhood vaccination coverage rates. SETTING: The 14 administrative regions of Senegal were chosen for analysis. PARTICIPANTS: DHS women's survey respondents with living children aged 12-23 months for survey years 2005-2019. OUTCOME MEASURES: Immunisation with the third dose of the diphtheria-tetanus-pertussis vaccine (DTP3), widely used as a proxy for estimating immunisation coverage levels and the retention of children in the vaccine programme. RESULTS: Factors associated with childhood vaccination coverage include urban residence (ß=0.61, p=0.0157), female literacy (ß=1.11, p=0.0007), skilled prenatal care (ß=1.80, p<0.0001) and self-reported ease of access to care when sick, considering travel distance to a healthcare facility (ß=-0.70, p=0.0009) and concerns over travelling alone (ß=-1.08, p<0.0001). Higher coverage with less variability over time was reported in urban areas near the capital and the coast (p=0.076), with increased coverage in recent years in more rural and landlocked areas. CONCLUSIONS: Childhood vaccination was more likely among children whose mothers had higher literacy, received skilled prenatal care and had perceived ease of access to care when sick. Overall, vaccination coverage is high in Senegal and disparities in coverage between regions have decreased significantly in recent years.

Drivers of early childhood vaccination success in Nepal, Senegal, and Zambia: a multiple case study analysis using the Consolidated Framework for Implementation Research.

INTRODUCTION: The fundamental components of a vaccine delivery system are well-documented, but robust evidence is needed on how the related processes and implementation strategies - including the facilitators and barriers - contribute to improvements in childhood vaccination coverage. The purpose of this study was to identify critical facilitators and barriers to the implementation of common interventions across three countries that have dramatically increased coverage of early childhood vaccination over the past 20 years, and to qualify common or divergent themes in their success. METHODS: We conducted 278 key informant interviews and focus group discussions with public health leaders at the regional, district, and local levels and community members in Nepal, Senegal, and Zambia to identify intervention activities and the facilitators and barriers to implementation. We used thematic analysis grounded in the Consolidated Framework for Implementation Research (CFIR) constructs of inner and outer settings to identify immunization program key facilitators and barriers. RESULTS: We found that the common facilitators to program implementation across the countries were the CFIR inner setting constructs of (1) networks and communications, (2) goals and feedback, (3) relative priority, and (4) readiness for implementation and outer setting constructs of (5) cosmopolitanism and (6) external policies and mandates. The common barriers were incentives and rewards, available resources, access to knowledge and information, and patients' needs and resources. Critical to the success of these national immunization programs were prioritization and codification of health as a human right, clear chain of command and shared ownership of immunization, communication of program goals and feedback, offering of incentives at multiple levels, training of staff central to vaccination education, the provision of resources to support the program, key partnerships and guidance on implementation and adoption of vaccination policies. CONCLUSION: Adequate organizational commitment, resources, communication, training, and partnerships were the most critical facilitators for these countries to improve childhood vaccination.

Critical interventions for demand generation in Zambia, Nepal, and Senegal with regards to the 5C psychological antecedents of vaccination.

Introduction: Childhood vaccination is an effective intervention for lowering the burden of infectious disease. Vaccine coverage has increased globally, but vaccine hesitancy and refusal threatens these gains. The 5C psychological antecedents of vaccination ("5C") provides a validated measure of "vaccine hesitancy or confidence" to assess individual thoughts and behaviors behind vaccination. We investigated population-level factors that contributed to high and sustained vaccination coverage in Zambia, Nepal, and Senegal, and alignment with the 5Cs. Methods: Data was collected in the larger Exemplars in Vaccine Delivery study, from focus group discussions (FDGs) and key informant interviews (KIIs) at the national, regional, district, health facility, and community levels of health systems in Zambia, Nepal, and Senegal. We assessed the demand environment, as relayed by participants, and identified interventions reported as successful for demand generation, then retroactively aligned the interventions with the 5C constructs. Results: Demand was positively correlated with high confidence and collective responsibility. Psychological constraints sometimes impacted demand. Physical constraints created barriers in some communities, particularly difficult to access (i.e., mountainous). Occasionally, physical constraints did not affect vaccination behavior - parents believed the benefits of vaccination worth pursuing. Factors negatively correlated with demand and intent, complacency and calculation, had limited impact. Critical interventions were: targeted and tailored health education activities (media partnerships, school outreach); community engagement; community ownership; and community involvement (community health workers, leaders, religious figures). Conclusion: We found similar interventions used to generate demand, with strategies aligned with the 5C constructs. Categorizing interventions by drivers of demand may help strategic planning and the division of resources; decision makers may choose to implement our suggested interventions. Assessing the 5Cs allows decision-makers to operationalize demand generation into concrete interventions and policies, and determine the individual impact of these constructs on the population and focus efforts on interventions tailored to a specific need.

Burden of disease attributable to unsafe drinking water, sanitation, and hygiene in domestic settings: a global analysis for selected adverse health outcomes.

BACKGROUND: Assessments of disease burden are important to inform national, regional, and global strategies and to guide investment. We aimed to estimate the drinking water, sanitation, and hygiene (WASH)-attributable burden of disease for diarrhoea, acute respiratory infections, undernutrition, and soil-transmitted helminthiasis, using the WASH service levels used to monitor the UN Sustainable Development Goals (SDGs) as counterfactual minimum risk-exposure levels. METHODS: We assessed the WASH-attributable disease burden of the four health outcomes overall and disaggregated by region, age, and sex for the year 2019. We calculated WASH-attributable fractions of diarrhoea and acute respiratory infections by country using modelled WASH exposures and exposure-response relationships from two updated meta-analyses. We used the WHO and UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene public database to estimate population exposure to different WASH service levels. WASH-attributable undernutrition was estimated by combining the population attributable fractions (PAF) of diarrhoea caused by unsafe WASH and the PAF of undernutrition caused by diarrhoea. Soil-transmitted helminthiasis was fully attributed to unsafe WASH. FINDINGS: We estimate that 1·4 (95% CI 1·3-1·5) million deaths and 74 (68-80) million disability-adjusted life-years (DALYs) could have been prevented by safe WASH in 2019 across the four designated outcomes, representing 2·5% of global deaths and 2·9% of global DALYs from all causes. The proportion of diarrhoea that is attributable to unsafe WASH is 0·69 (0·65-0·72), 0·14 (0·13-0·17) for acute respiratory infections, and 0·10 (0·09-0·10) for undernutrition, and we assume that the entire disease burden from soil-transmitted helminthiasis was attributable to unsafe WASH. INTERPRETATION: WASH-attributable burden of disease estimates based on the levels of service established under the SDG framework show that progress towards the internationally agreed goal of safely managed WASH services for all would yield major public-health returns. FUNDING: WHO and Foreign, Commonwealth & Development Office.

Quantifying Factors Associated with Personal Hygiene as Measured by the qPHAT Methodology: Andilaye Trial, Ethiopia.

Many water, sanitation, and hygiene (WASH) interventions target improvements in personal hygiene behaviors. Yet measuring personal hygiene behaviors is a challenge due to a lack of reliable, valid, objective, and simple-to-use approaches. The purpose of this study was to examine differences between two types of hygiene outcome measures and their ability to detect relationships between WASH-related behavioral factors and behaviors. We compared hygiene outcomes generated by the Quantitative Personal Hygiene Assessment Tool (qPHAT), which yields objective measures of cleanliness on an 11-point scale, and those generated by conventional, dichotomous indicators of cleanliness. We used cross-sectional data on hygiene outcomes related to facial and hand cleanliness collected during the Andilaye Trial, an impact evaluation of a community-based WASH intervention implemented in Amhara, Ethiopia. We fit multivariable models to examine associations between measures of children's facial and hand cleanliness, via both qPHAT and dichotomous indicators, and 1) household WASH conditions, 2) psychosocial factors, and 3) reported personal hygiene practices. The qPHAT-generated outcomes were able to detect relationships between intermediate behavioral factors and hygiene outcomes that dichotomous indicators were not, including associations with water insecurity and various psychosocial factors. qPHAT-generated outcomes were negatively associated with reported face washing practices, suggesting a bias in reported behaviors. Our study highlights the limitations of reported practices and dichotomous hygiene indicators and indicates that using more quantitative hygiene outcome measures, such as those generated by qPHAT, may reveal important intermediate factors that influence hygiene behavior and support improved monitoring and evaluation of interventions.

Critical success factors for high routine immunization performance: A case study of Senegal.

Background: The essential components of a vaccine delivery system are well-documented, but robust evidence is lacking on how policies and implementation strategies are operationalized to drive catalytic improvements in coverage. To address this gap, we identified success factors that supported improvements in routine immunization coverage in Senegal, especially from 2000 to 2019. Methods: We identified Senegal as an exemplar in the delivery of childhood vaccines through analysis of DTP1 and DTP3 coverage data. Through interviews and focus group discussions at the national, regional, district, health facility, and community-level, we investigated factors that contributed to high and sustained vaccination coverage. We conducted a thematic analysis through application of implementation science frameworks to determine critical success factors. We triangulated these findings with quantitative analyses using publicly available data. Results: The following success factors emerged: 1) Strong political will and prioritization of resources for immunization programming supported urgent allocation of funding and supplies; 2) Collaboration between the Ministry of Health and Social Action and external partners fostered innovation, capacity building, and efficiency; 3) Improved surveillance, monitoring, and evaluation allowed for timely and evidence-based decision making; 4) Community ownership of vaccine service delivery supported tailored programming and response to local needs; and 5) Community health workers spearheaded vaccine promotion and demand generation for vaccines. Conclusion: The vaccination program in Senegal was supported by evidence-based decision making at the national-level, alignment of priorities between governmental entities and external partners, and strong community engagement initiatives that fostered local ownership of vaccine delivery and uptake. High routine immunization coverage was likely driven by prioritization of immunization programming, improved surveillance systems, a mature and reliable community health worker program, and tailored strategies for addressing geographical, social, and cultural barriers.

Effectiveness of handwashing with soap for preventing acute respiratory infections in low-income and middle-income countries: a systematic review and meta-analysis.

BACKGROUND: Acute respiratory infection (ARI) is a leading cause of morbidity and mortality globally, with 83% of ARI mortality occurring in low-income and middle-income countries (LMICs) before the COVID-19 pandemic. We aimed to estimate the effect of interventions promoting handwashing with soap on ARI in LMICs. METHODS: In our systematic review and meta-analysis, we searched MEDLINE, Embase, Web of Science, Scopus, Cochrane Library, Global Health, and Global Index Medicus for studies of handwashing with soap interventions in LMICs from inception to May 25, 2021. We included randomised and non-randomised controlled studies of interventions conducted in domestic, school, or childcare settings. Interventions promoting hand hygiene methods other than handwashing with soap were excluded, as were interventions in health-care facilities or the workplace. The primary outcome was ARI morbidity arising from any pathogen for participants of any age. Secondary outcomes were lower respiratory infection, upper respiratory infection, influenza confirmed by diagnostic test, COVID-19 confirmed by diagnostic test, and all-cause mortality. We extracted relative risks (RRs), using random-effects meta-analysis to analyse study results, and metaregression to evaluate heterogeneity. We assessed risk of bias in individual studies using an adapted Newcastle-Ottawa scale, and assessed the overall body of evidence using a Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The study is registered with PROSPERO, CRD42021231414. FINDINGS: 26 studies with 161 659 participants met inclusion criteria, providing 27 comparisons (21 randomised). Interventions promoting handwashing with soap reduced any ARI compared with no handwashing intervention (RR 0·83 [95% CI 0·76-0·90], I2 88%; 27 comparisons). Interventions also reduced lower respiratory infections (0·78 [0·64-0·94], I2 64%; 12 comparisons) and upper respiratory infections (0·74 [0·59-0·93], I2 91%; seven comparisons), but not test-confirmed influenza (0·94 [0·42-2·11], I2 90%; three comparisons), test-confirmed COVID-19 (no comparisons), or all-cause mortality (prevalence ratio 0·95 [95% CI 0·71-1·27]; one comparison). For ARI, no heterogeneity covariates were significant at p<0·1 and the GRADE rating was moderate certainty evidence. INTERPRETATION: Interventions promoting handwashing with soap can reduce ARI in LMICs, and could help to prevent the large burden of respiratory disease. FUNDING: Bill & Melinda Gates Foundation, Reckitt Global Hygiene Institute, and UK FCDO.

Study design and rationale for the PAASIM project: a matched cohort study on urban water supply improvements and infant enteric pathogen infection, gut microbiome development and health in Mozambique.

INTRODUCTION: Despite clear linkages between provision of clean water and improvements in child health, limited information exists about the health impacts of large water infrastructure improvements in low-income settings. Billions of dollars are spent annually to improve urban water supply, and rigorous evaluation of these improvements, especially targeting informal settlements, is critical to guide policy and investment strategies. Objective measures of infection and exposure to pathogens, and measures of gut function, are needed to understand the effectiveness and impact of water supply improvements. METHODS AND ANALYSIS: In the PAASIM study, we examine the impact of water system improvements on acute and chronic health outcomes in children in a low-income urban area of Beira, Mozambique, comprising 62 sub-neighbourhoods and ~26 300 households. This prospective matched cohort study follows 548 mother-child dyads from late pregnancy through 12 months of age. Primary outcomes include measures of enteric pathogen infections, gut microbiome composition and source drinking water microbiological quality, measured at the child's 12-month visit. Additional outcomes include diarrhoea prevalence, child growth, previous enteric pathogen exposure, child mortality and various measures of water access and quality. Our analyses will compare (1) subjects living in sub-neighbourhoods with the improved water to those living in sub-neighbourhoods without these improvements; and (2) subjects with household water connections on their premises to those without such a connection. This study will provide critical information to understand how to optimise investments for improving child health, filling the information gap about the impact of piped water provision to low-income urban households, using novel gastrointestinal disease outcomes. ETHICS AND DISSEMINATION: This study was approved by the Emory University Institutional Review Board and the National Bio-Ethics Committee for Health in Mozambique. The pre-analysis plan is published on the Open Science Framework platform (https://osf.io/4rkn6/). Results will be shared with relevant stakeholders locally, and through publications.

Measurement in the study of human exposure to animal feces: A systematic review and audit.

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.

Exploring water, sanitation, and hygiene coverage targets for reaching and sustaining trachoma elimination: G-computation analysis.

BACKGROUND: Trachoma is the leading infectious cause of blindness. To reduce transmission, water, sanitation, and hygiene (WaSH) improvements are promoted through a comprehensive public health strategy. Evidence supporting the role of WaSH in trachoma elimination is mixed and it remains unknown what WaSH coverages are needed to effectively reduce transmission. METHODS/FINDINGS: We used g-computation to estimate the impact on the prevalence of trachomatous inflammation-follicular among children aged 1-9 years (TF1-9) when hypothetical WaSH interventions raised the minimum coverages from 5% to 100% for "nearby" face-washing water (<30 minutes roundtrip collection time) and adult latrine use in an evaluation unit (EU). For each scenario, we estimated the generalized prevalence difference as the TF1-9 prevalence under the intervention scenarios minus the observed prevalence. Data from 574 cross-sectional surveys conducted in 16 African and Eastern Mediterranean countries were included. Surveys were conducted from 2015-2019 with support from the Global Trachoma Mapping Project and Tropical Data. When modeling interventions among EUs that had not yet met the TF1-9 elimination target, increasing nearby face-washing water and latrine use coverages above 30% was generally associated with consistent decreases in TF1-9. For nearby face-washing water, we estimated a ≥25% decrease in TF1-9 at 65% coverage, with a plateau upon reaching 85% coverage. For latrine use, the estimated decrease in TF1-9 accelerated from 80% coverage upward, with a ≥25% decrease in TF1-9 by 85% coverage. Among EUs that had previously met the elimination target, results were inconclusive. CONCLUSIONS: Our results support Sustainable Development Goal 6 and provide insight into potential WaSH-related coverage targets for trachoma elimination. Targets can be tested in future trials to improve evidence-based WaSH guidance for trachoma.

Leveraging infectious disease models to interpret randomized controlled trials: Controlling enteric pathogen transmission through water, sanitation, and hygiene interventions.

Randomized controlled trials (RCTs) evaluate hypotheses in specific contexts and are often considered the gold standard of evidence for infectious disease interventions, but their results cannot immediately generalize to other contexts (e.g., different populations, interventions, or disease burdens). Mechanistic models are one approach to generalizing findings between contexts, but infectious disease transmission models (IDTMs) are not immediately suited for analyzing RCTs, since they often rely on time-series surveillance data. We developed an IDTM framework to explain relative risk outcomes of an infectious disease RCT and applied it to a water, sanitation, and hygiene (WASH) RCT. This model can generalize the RCT results to other contexts and conditions. We developed this compartmental IDTM framework to account for key WASH RCT factors: i) transmission across multiple environmental pathways, ii) multiple interventions applied individually and in combination, iii) adherence to interventions or preexisting conditions, and iv) the impact of individuals not enrolled in the study. We employed a hybrid sampling and estimation framework to obtain posterior estimates of mechanistic parameter sets consistent with empirical outcomes. We illustrated our model using WASH Benefits Bangladesh RCT data (n = 17,187). Our model reproduced reported diarrheal prevalence in this RCT. The baseline estimate of the basic reproduction number [Formula: see text] for the control arm (1.10, 95% CrI: 1.07, 1.16) corresponded to an endemic prevalence of 9.5% (95% CrI: 7.4, 13.7%) in the absence of interventions or preexisting WASH conditions. No single pathway was likely able to sustain transmission: pathway-specific [Formula: see text] for water, fomites, and all other pathways were 0.42 (95% CrI: 0.03, 0.97), 0.20 (95% CrI: 0.02, 0.59), and 0.48 (95% CrI: 0.02, 0.94), respectively. An IDTM approach to evaluating RCTs can complement RCT analysis by providing a rigorous framework for generating data-driven hypotheses that explain trial findings, particularly unexpected null results, opening up existing data to deeper epidemiological understanding.

Determinants of food preparation and hygiene practices among caregivers of children under two in Western Kenya: a formative research study.

INTRODUCTION: Diarrhea is a leading cause of child morbidity and mortality worldwide and is linked to early childhood stunting. Food contamination from improper preparation and hygiene practices is an important transmission pathway for exposure to enteric pathogens. Understanding the barriers and facilitators to hygienic food preparation can inform interventions to improve food hygiene. We explored food preparation and hygiene determinants including food-related handwashing habits, meal preparation, cooking practices, and food storage among caregivers of children under age two in Western Kenya. METHODS: We used the Capabilities, Opportunities, and Motivations model for Behavior Change (COM-B) framework in tool development and analysis. We conducted 24 focus group discussions with mothers (N = 12), fathers (N = 6), and grandmothers (N = 6); 29 key informant interviews with community stakeholders including implementing partners and religious and community leaders; and 24 household observations. We mapped the qualitative and observational data onto the COM-B framework to understand caregivers' facilitators and barriers to food preparation and hygiene practices. RESULTS: Facilitators and barriers to food hygiene and preparation practices were found across the COM-B domains. Caregivers had the capability to wash their hands at critical times; wash, cook, and cover food; and clean and dry utensils. Barriers to food hygiene and preparation practices included lack of psychological capability, for instance, caregivers' lack of knowledge of critical times for handwashing, lack of perceived importance of washing some foods before eating, and not knowing the risks of storing food for more than four hours without refrigerating and reheating. Other barriers were opportunity-related, including lack of resources (soap, water, firewood) and an enabling environment (monetary decision-making power, social support). Competing priorities, socio-cultural norms, religion, and time constraints due to work hindered the practice of optimal food hygiene and preparation behaviors. CONCLUSION: Food hygiene is an underexplored, but potentially critical, behavior to mitigate fecal pathogen exposure for young children. Our study revealed several knowledge and opportunity barriers that could be integrated into interventions to enhance food hygiene.

Spatial heterogeneity of neighborhood-level water and sanitation access in informal urban settlements: A cross-sectional case study in Beira, Mozambique.

Rapid urbanization, resulting in population growth within informal settlements, has worsened exclusion and inequality in access to water and sanitation (WASH) services in the poorest and most marginalized communities. In this study, we describe the heterogeneity in water service satisfaction and WASH access in low-income, peri-urban neighborhoods of Beira, Mozambique, and examine whether this heterogeneity can be explained by distance to water distribution mains. Using spatial statistics and regression analyses, we identify spatial heterogeneity in household WASH access, as well as consumer-reported satisfaction with water services (services, pressure, quality, and sufficient quantity). We find that as distance from the water main increased, both access to an improved water source at the household and satisfaction with water pressure decreases, and water supply intermittency increases, controlling for household density and socioeconomic status. The odds of a household having access to a water source at the household or on the compound decreases with every 100-meter increase in distance from a water main pipe (odds ratio [OR] 0.87, 95% confidence interval [CI]: 0.82, 0.92). Satisfaction with water services also decreases with every 100-meter increase in distance from a water main pipe (OR: 0.80; 95% CI: 0.69, 0.94). Days of availability in the past week decreases by a factor of 0.22 for every 100-meter increase in distance from the water main (95% CI: -0.29, -0.15). Findings from this study highlight the unequal household access to water and sanitation in urban informal settlements, even within low-income neighborhoods. Describing this heterogeneity of access to water services, sanitation, and satisfaction-and the factors influencing them-can inform stakeholders and guide the development of infrastructural solutions to reduce water access inequities within urban settings.