1. Background of the study

Diarrhoeal disease remains one of the leading causes of illness and death among children under five globally, and is closely linked to unsafe water, inadequate sanitation and poor hygiene (WASH) (UNICEF, 2024; Wolf et al., 2022). Robust syntheses show that improvements across the WASH service ladder — especially reliably available, safely managed drinking water, safe sanitation (sewerage where feasible) and consistent handwashing with soap — substantially reduce childhood diarrhoea, with point-of-use water filtration, higher quality on-premises water, sewer connections and handwashing showing some of the largest effects (Wolf et al., 2022). Contextual evidence across Africa indicates that the burden of diarrhoeal illnesses clusters in areas of household and community WASH deprivation and is mediated by socioeconomic factors, household crowding, childcare practices (stool disposal, complementary feeding) and access to timely treatment (Azanaw et al., 2024). Rapid urbanization in Lagos has produced dense informal settlements where public infrastructure and municipal services are fragmented, water supply is often informal and intermittent, and sanitation and waste management systems are inadequate — conditions that create persistent exposure to enteric pathogens (Akoteyon, Aliu & Soladoye, 2021; Gilbert & Shi, 2023). Studies focused on Lagos slums report high levels of WASH deprivation (poor access to improved water, shared or unimproved sanitation, and absent handwashing facilities) and link these deprivations to elevated risk of water-borne and faecal-oral diseases among children (Akoteyon et al., 2021; Victor et al., 2025). Within Lagos the Badia/Badia-East / Ijora-Badia cluster exemplifies these vulnerabilities: spatial analyses and local environmental health surveys describe dense built environments, unstable or informal water sources, poor drainage and inadequate sanitation infrastructure that together magnify exposure after seasonal floods and during tidal inundation events (Gilbert & Shi, 2023; Akoteyon et al., 2021). At the same time, national analyses show that a large proportion of Nigerian children are deprived of at least one WASH component — sanitation deprivation is especially common — and that household wealth, education of the household head, household size and place of residence are consistent predictors of WASH access (Victor et al., 2025). Regionally-focused reviews of determinants of childhood diarrhoea across Africa emphasize that WASH measures interact with socio-demographic and behavioural drivers (caregiver knowledge, stool disposal, breastfeeding practices) and that solutions therefore require both infrastructure and behaviour-change components tailored to local social networks (Azanaw et al., 2024). In short: strong global evidence links WASH improvements to reduced diarrhoea, and multiple recent Nigerian and Lagos studies document the high prevalence of WASH deprivation in slums — but locally-granular data from specific communities like Ijora-Badia are limited. That gap makes planning targeted, feasible interventions (e.g., piped supply upgrades, community handwashing points, safe child stool disposal campaigns) difficult to prioritise and evaluate.

2. Statement of the problem

Despite national and municipal WASH initiatives, many urban informal settlements in Lagos continue to suffer substantial gaps in water supply reliability, safe sanitation and household hygiene facilities. These deprivations contribute to an ongoing high burden of diarrhoeal disease among children under five, yet available data are typically at city or state level and do not capture neighbourhood-level heterogeneity in exposure, behaviours and health outcomes (Victor et al., 2025; Akoteyon et al., 2021). In Ijora-Badia, routine health information and environmental assessments suggest frequent use of informal water vendors, shared or unimproved latrines, limited handwashing infrastructure and recurrent flooding that contaminates drinking water sources — conditions that plausibly increase diarrhoea incidence among young children (Gilbert & Shi, 2023; Akoteyon et al., 2021). However, the absence of a recent, community-level prevalence study means programme managers lack the local baseline needed to: (a) quantify current diarrhoea prevalence among under-fives; (b) identify which WASH practices and service shortfalls (source type, time to water, latrine sharing, handwashing availability, child stool disposal) most strongly predict disease; and (c) prioritise low-cost, high-impact interventions (for example, point-of-use treatment vs. community taps vs. sanitation subsidies). Without such granular evidence, interventions risk being mismatched to local determinants (infrastructure investment where behaviour change is more urgent, or vice versa), perpetuating avoidable morbidity and inefficient use of limited resources (Azanaw et al., 2024; Wolf et al., 2022).

3. Aim and objectives of the study

Aim: To assess WASH practices and their association with diarrhoeal disease prevalence among children under five in Ijora-Badia community, Apapa LGA, Lagos State.

Specific objectives:

1. Estimate the two-week prevalence of diarrhoeal disease among children aged 0–59 months in Ijora-Badia.
2. Describe household WASH characteristics and caregiver WASH practices (main water source, time to fetch water, water storage and treatment, toilet type and sharing, presence of handwashing facility with water and soap, child stool disposal).
3. Identify associations between household WASH variables and recent diarrhoeal episodes, adjusting for child age, breastfeeding status, household wealth proxy and caregiver education.
4. Document health-facility treatmentseeking behaviour for diarrhoea (ORS/zinc use, informal care) and facility WASH availability (water, sanitation, hygiene) at the nearest public clinic.
5. Produce locally-specific, evidence-based recommendations for priority WASH interventions and community engagement strategies.

4. Research questions

1. What is the two-week prevalence of diarrhoea among children 0–59 months in Ijora-Badia community?
2. Which household WASH characteristics and caregiver practices are most strongly associated with recent diarrhoea in under-five children?
3. How do socio-demographic factors (household wealth proxy, caregiver education, household crowding) modify the relationship between WASH and diarrhoeal outcomes?
4. What are the predominant care-seeking patterns and treatment gaps (ORS, zinc) for diarrhoea in the community?
5. What service-level WASH gaps exist at the primary health facility level that could affect infection control and case management?

5. Scope of the study

Design: Cross-sectional household survey combined with a health-facility WASH assessment and brief observational spot checks for environmental hazards (drainage, visible faecal contamination).

Study area (single area of study, per your instruction): Ijora-Badia community, Apapa Local Government Area, Lagos State.

Population: Caregivers of children aged 0–59 months who have lived in Ijora-Badia for ?6 months; selected primary care clinics serving the community for facility WASH checklist.

Instruments: Structured interviewer-administered household questionnaire (child health history, diarrhoea in past 2 weeks, feeding practices, WASH access and practice), spot-check observation checklist (water storage, presence of soap at handwashing station), facility WASH checklist (water availability, sanitation, hand hygiene supplies), and GPS mapping of sampled households for spatial clustering analyses.

Sample and sampling: Probability cluster sampling of households within Ijora-Badia (number of clusters and sample size to be calculated based on estimated 2-week diarrhoea prevalence, desired precision and design effect).

Data collection period: Dry and rainy season considerations (if possible collect within one season or stratify by season to account for flood-related contamination).

Analysis: Descriptive prevalence estimates with 95% CIs, bivariate analyses of WASH variables vs. diarrhoea, and multivariable logistic regression to identify independent predictors; spatial mapping of hotspots if clustering observed.

Ethics & dissemination: Local ethical approval (Lagos State Health Research Ethics Committee), community sensitisation via ward leaders and community health volunteers, and dissemination of plain-language findings to community and Apapa LGA health authorities to inform rapid, targeted interventions.

References

Akoteyon, I. S., Aliu, I. R., & Soladoye, O. (2021). Household levels of deprivation to WaSH and residential conditions in slum settlements of Lagos, Nigeria. Journal of Water, Sanitation and Hygiene for Development, 11(1), 60–72. https://doi.org/10.2166/washdev.2020.157

Azanaw, J., Malede, A., Yalew, H. F., & Worede, E. A. (2024). Determinants of diarrhoeal diseases among under-five children in Africa (2013–2023): A comprehensive systematic review highlighting geographic variances, socioeconomic influences, and environmental factors. BMC Public Health, 24, 2399. https://doi.org/10.1186/s12889-024-19962-0

Gilbert, K. M., & Shi, Y. (2023). Slums evolution and sustainable urban growth: A comparative study of Makoko and Badia-East areas in Lagos City. Sustainability, 15(19), 14353. https://doi.org/10.3390/su151914353

UNICEF. (2024). Diarrhoea (UNICEF Data). UNICEF. (Last updated Nov 2024). https://data.unicef.org/topic/child-health/diarrhoeal-disease/

Victor, C., Kupoluyi, J. A., Oyinlola, F. F., & Sule, V. O. (2025). Prevalence and factors associated with water, sanitation and hygiene (WASH) facilities deprivation among children in Nigeria. BMC Pediatrics, 25, 102. https://doi.org/10.1186/s12887-025-05463-5

Wolf, J., Hubbard, S., Brauer, M., Ambelu, A., Arnold, B. F., Bain, R., Bauza, V., Brown, J., Caruso, B. A., Clasen, T., Colford, J. M., Freeman, M. C., Gordon, B., Johnston, R. B., Mertens, A., Prüss-Ustün, A., Ross, I., Stanaway, J., Zhao, J. T., Cumming, O., & Boisson, S. (2022). Effectiveness of interventions to improve drinking water, sanitation, and handwashing with soap on risk of diarrhoeal disease in children in low-income and middle-income settings: A systematic review and meta-analysis. The Lancet, 400(10345), 27–40. https://doi.org/10.1016/S0140-6736(22)00937-0