Association of inadequate WaSH, housing, and infectious diseases with undernutrition hotspots among children under five: findings from a national survey in Indonesia

Background: Undernutrition in Indonesia persists amid regional disparities in household water, sanitation, hygiene (WaSH), housing, and infectious disease burden.This study quantified associations between household environmental conditions, recent infections, and child undernutrition to inform geographically targeted interventions. Methods:We conducted a secondary cross-sectional analysis of the 2023 Indonesia Health Survey, including 85,118 children aged 0-59 months.Exposures were household access to improved water, safe sanitation, basic hygiene, and adequate housing, plus self-reported diarrhea, ARI, and pneumonia; outcomes were stunting, underweight, and wasting.Multivariable logistic regression accounted for clustering, stratification, and sample weights, and provincial-level spatial overlays in QGIS mapped environmental and epidemiological hotspots.Results: National prevalences were 24.2% (stunting), 17.7% (underweight), and 9.8% (wasting).After adjustment, absence of basic hygiene increased odds of stunting (aOR 1.37; 1.33-1.42),underweight (aOR 1.42; 1.37-1.48),and wasting (aOR 1.34; 1.28-1.41).Unimproved water was associated with stunting (aOR 1.26; 1.18-1.34)and underweight (aOR 1.12; 1.04-1.20);inadequate housing raised adjusted odds of stunting (aOR 1.09; 1.05-1.15)and underweight (aOR 1.10; 1.05-1.17).Diarrhea predicted all outcomes (stunting aOR 1.21; 1.15-1.28;underweight aOR 1.19; 1.11-1.26;wasting aOR J o u r n a l P r e -p r o o f 1.13; 1.04-1.22);ARI and pneumonia were independently associated with underweight (aOR 1.13; 1.09-1.17)and stunting (aOR 1.12; 1.08-1.17),respectively.Spatial mapping highlighted Eastern and Central provinces as concurrent high-risk areas. Conclusion: Inadequate WaSH, poor housing, and recent infectious disease episodes independently elevate child undernutrition risk; geospatially targeted, multisectoral WaSH, housing, and infectioncontrol interventions in identified hotspots are warranted.