Introduction: The essential components of a vaccine delivery system are well-documented, but robust evidence on how and why the related processes and implementation strategies drive catalytic improvements in vaccination coverage are not well established. To address this gap, we identified critical success factors that may have led to substantial improvements in routine childhood immunization coverage in Nepal from 2000 through 2019. Methods: We identified Nepal as an exemplar in the delivery of early childhood immunization through analysis of DTP1 and DTP3 coverage data. Through interviews and focus group discussions at the national, regional, district, health post, and community level, we investigated factors that contributed to high and sustained vaccine 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) Codification of health as a human right, - along with other vaccine-specific legislation - ensured the stability of vaccination programming; 2) National and multi-national partnerships supported information sharing, division of labor, and mutual capacity building; 3) Pro-vaccine messaging through various mediums, which was tailored to local needs, generated public awareness; 4) Female Community Health Volunteers educated community members as trusted and compassionate neighbors; and 5) Cultural values fostered collective responsibility and community ownership of vaccine coverage. Conclusion: This case study of Nepal suggests that the success of its national immunization program relied on the engagement and understanding of the beneficiaries. The immunization program was supported by consistent and reliable commitment, collaboration, awareness, and collective responsibility between the government, community, and partners. These networks are strengthened through a collective dedication to vaccination programming and a universal belief in health as a human right.

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.

Background The importance of maternal sanitation behaviour during pregnancy for birth outcomes remains unclear. Poor sanitation practices can promote infection and induce stress during pregnancy and may contribute to adverse pregnancy outcomes (APOs). We aimed to assess whether poor sanitation practices were associated with increased risk of APOs such as preterm birth and low birth weight in a population-based study in rural India. Methods and Findings A prospective cohort of pregnant women (n = 670) in their first trimester of pregnancy was enrolled and followed until birth. Socio-demographic, clinical, and anthropometric factors, along with access to toilets and sanitation practices, were recorded at enrolment (12th week of gestation). A trained community health volunteer conducted home visits to ensure retention in the study and learn about study outcomes during the course of pregnancy. Unadjusted odds ratios (ORs) and adjusted odds ratios (AORs) and 95% confidence intervals for APOs were estimated by logistic regression models. Of the 667 women who were retained at the end of the study, 58.2% practiced open defecation and 25.7% experienced APOs, including 130 (19.4%) preterm births, 95 (14.2%) births with low birth weight, 11 (1.7%) spontaneous abortions, and six (0.9%) stillbirths. Unadjusted ORs for APOs (OR: 2.53; 95% CI: 1.72–3.71), preterm birth (OR: 2.36; 95% CI: 1.54–3.62), and low birth weight (OR: 2.00; 95% CI: 1.24–3.23) were found to be significantly associated with open defecation practices. After adjustment for potential confounders such as maternal socio-demographic and clinical factors, open defecation was still significantly associated with increased odds of APOs (AOR: 2.38; 95% CI: 1.49–3.80) and preterm birth (AOR: 2.22; 95% CI: 1.29–3.79) but not low birth weight (AOR: 1.61; 95% CI: 0.94–2.73). The association between APOs and open defecation was independent of poverty and caste. Even though we accounted for several key confounding factors in our estimates, the possibility of residual confounding should not be ruled out. We did not identify specific exposure pathways that led to the outcomes. Conclusions This study provides the first evidence, to our knowledge, that poor sanitation is associated with a higher risk of APOs. Additional studies are required to elucidate the socio-behavioural and/or biological basis of this association so that appropriate targeted interventions might be designed to support improved birth outcomes in vulnerable populations. While it is intuitive to expect that caste and poverty are associated with poor sanitation practice driving APOs, and we cannot rule out additional confounders, our results demonstrate that the association of poor sanitation practices (open defecation) with these outcomes is independent of poverty. Our results support the need to assess the mechanisms, both biological and behavioural, by which limited access to improved sanitation leads to APOs.

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.

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.

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.

Behaviors related to water, sanitation, and hygiene (WASH) are key drivers of infectious disease transmission, and experiences of WASH are potential influencers of mental well-being. Important knowledge gaps exist related to the content and delivery of effective WASH programs and their associated health impacts, particularly within the contexts of government programs implemented at scale. We developed and tested a demand-side intervention called Andilaye, which aimed to change behaviors related to sanitation, personal hygiene, and household environmental sanitation. This theory-informed intervention was delivered through the existing Ethiopian Health Extension Programme (HEP). It was a multilevel intervention with a catalyzing event at the community level and behavior change activities at group and household levels. We randomly selected and assigned 50 kebeles (sub-districts) from three woredas (districts), half to receive the Andilaye intervention, and half the standard of care sanitation and hygiene programming (i.e., community-led total sanitation and hygiene [CLTSH]). We collected data on WASH access, behavioral outcomes, and mental well-being. A total of 1,589 households were enrolled into the study at baseline; 1,472 households (94%) participated in an endline assessment two years after baseline, and approximately 14 months after the initiation of a multi-level intervention. The intervention did not improve construction of latrines (prevalence ratio [PR]: 0.99; 95% CI: 0.82, 1.21) or handwashing stations with water (PR: 0.96; 95% CI: 0.72, 1.26), or the removal of animal feces from the compound (PR: 1.10; 95% CI: 0.95, 1.28). Nor did it impact anxiety (PR: 0.90; 95% CI: 0.72, 1.11), depression (PR: 0.83; 95% CI: 0.64, 1.07), emotional distress (PR: 0.86; 95% CI: 0.67, 1.09) or well-being (PR: 0.90; 95% CI: 0.74, 1.10) scores. We report limited impact of the intervention, as delivered, on changes in behavior and mental well-being. The effectiveness of the intervention was limited by poor intervention fidelity. While sanitation and hygiene improvements have been documented in Ethiopia, behavioral slippage, or regression to unimproved practices, in communities previously declared open defecation free is widespread. Evidence from this trial may help address knowledge gaps related to challenges associated with scalable alternatives to CLTSH and inform sanitation and hygiene programming and policy in Ethiopia and beyond. Trial registration: This trial was registered with clinicaltrials.gov (NCT03075436) on March 9, 2017.

Background: Diarrhoeal disease is a leading cause of childhood illness and death globally, and Shigella is a major aetiological contributor for which a vaccine might soon be available. The primary objective of this study was to model the spatiotemporal variation in paediatric Shigella infection and map its predicted prevalence across low-income and middle-income countries (LMICs). Methods: Individual participant data for Shigella positivity in stool samples were sourced from multiple LMIC-based studies of children aged 59 months or younger. Covariates included household-level and participant-level factors ascertained by study investigators and environmental and hydrometeorological variables extracted from various data products at georeferenced child locations. Multivariate models were fitted and prevalence predictions obtained by syndrome and age stratum. Findings: 20 studies from 23 countries (including locations in Central America and South America, sub-Saharan Africa, and south and southeast Asia) contributed 66 563 sample results. Age, symptom status, and study design contributed most to model performance followed by temperature, wind speed, relative humidity, and soil moisture. Probability of Shigella infection exceeded 20% when both precipitation and soil moisture were above average and had a 43% peak in uncomplicated diarrhoea cases at 33°C temperatures, above which it decreased. Compared with unimproved sanitation, improved sanitation decreased the odds of Shigella infection by 19% (odds ratio [OR]=0·81 [95% CI 0·76–0·86]) and open defecation decreased them by 18% (OR=0·82 [0·76–0·88]). Interpretation: The distribution of Shigella is more sensitive to climatological factors, such as temperature, than previously recognised. Conditions in much of sub-Saharan Africa are particularly propitious for Shigella transmission, although hotspots also occur in South America and Central America, the Ganges–Brahmaputra Delta, and the island of New Guinea. These findings can inform prioritisation of populations for future vaccine trials and campaigns. Funding: NASA, National Institutes of Health–The National Institute of Allergy and Infectious Diseases, and Bill & Melinda Gates Foundation.

BACKGROUND: Safe water, sanitation, and hygiene (WaSH) is important for health, livelihoods, and economic development, but WaSH programs have often underdelivered on expected health benefits. Underperformance has been attributed partly to poor ability to retain effectiveness following adaptation to facilitate WaSH programs' implementation in diverse contexts. Adaptation of WaSH interventions is common but often not done systematically, leading to poor outcomes. Models and frameworks from the adaptation literature have potential to improve WaSH adaptation to facilitate implementation and retain effectiveness. However, these models and frameworks were designed in a healthcare context, and WaSH interventions are typically implemented outside traditional health system channels. The purpose of our work was to develop an adaptation model tailored specifically to the context of WaSH interventions. METHODS: We conducted a scoping review to identify key adaptation steps and identify tools to support systematic adaptation. To identify relevant literature, we conducted a citation search based on three recently published reviews on adaptation. We also conducted a systematic database search for examples of WaSH adaptation. We developed a preliminary model based on steps commonly identified across models in adaptation literature, and then tailored the model to the WaSH context using studies yielded by our systematic search. We compiled a list of tools to support systematic data collection and decision-making throughout adaptation from all included studies. RESULTS AND CONCLUSIONS: Our model presents adaptation steps in five phases: intervention selection, assessment, preparation, implementation, and sustainment. Phases for assessment through sustainment are depicted as iterative, reflecting that once an intervention is selected, adaptation is a continual process. Our model reflects the specific context of WaSH by including steps to engage non-health and lay implementers and to build consensus among diverse stakeholders with potentially competing priorities. We build on prior adaptation literature by compiling tools to support systematic data collection and decision-making, and we describe how they can be used throughout adaptation steps. Our model is intended to improve program outcomes by systematizing adaptation processes and provides an example of how systematic adaptation can occur for interventions with health goals but that are implemented outside conventional health system channels.

Billions of people globally, living with various degrees of water insecurity, obtain their household and drinking water from diverse sources that can absorb a disproportionate amount of a household's income. In theory, there are income and expenditure thresholds associated with effective mitigation of household water insecurity, but there is little empirical research about these mechanisms and thresholds in low- and middle-income settings. This study used data from 3655 households from 23 water-insecure sites in 20 countries to explore the relationship between cash water expenditures (measured as a Z-score, percent of income, and Z-score of percent of income) and a household water insecurity score, and whether income moderated that relationship. We also assessed whether water expenditures moderated the relationships between water insecurity and both food insecurity and perceived stress. Using tobit mixed effects regression models, we observed a positive association between multiple measures of water expenditures and a household water insecurity score, controlling for demographic characteristics and accounting for clustering within neighborhoods and study sites. The positive relationships between water expenditures and water insecurity persisted even when adjusted for income, while income was independently negatively associated with water insecurity. Water expenditures were also positively associated with food insecurity and perceived stress. These results underscore the complex relationships between water insecurity, food insecurity, and perceived stress and suggest that water infrastructure interventions that increase water costs to households without anti-poverty and income generation interventions will likely exacerbate experiences of household water insecurity, especially for the lowest-income households.