THE HIDDEN BURDEN: ASSESSING THE EMPIRICAL GAPS IN RESEARCH LINKING WATER, SANITATION, AND HYGIENE (WASH) TO CHILDHOOD ACUTE INFECTIONS IN LOW- AND MIDDLE-INCOME COUNTRIES

Abstract

Sustainable Development Goal 3 (SDG 3) emphasizes ensuring healthy lives and promoting well-being for all. However, child mortality in low- and middle-income countries (LMICs) remains unacceptably high, largely due to inadequate access to clean water, sanitation, and hygiene (WASH) services. This persistent health challenge threatens LMICs’ progress toward SDG 3 by 2030. This systematic review assessed the current scope of empirical research examining child health outcomes associated with WASH access across LMICs, identifying global gaps in evidence related to diarrhea, child development and stunting, and acute infections (excluding diarrhea). Following PRISMA guidelines, a comprehensive search was conducted in June 2025 across Taylor & Francis, EBSCOhost, and PubMed, yielding 230 records. After removing duplicates, 111 studies were screened, and 48 met inclusion criteria for thematic and content analysis. Only empirical studies reporting measurable child health outcomes were included. Findings revealed a disproportionate research emphasis: diarrhea accounted for 62.5% of all outcomes, reflecting its major global health burden. Child development and stunting represented 29.17%, while acute infections, such as respiratory infections, helminths, and trachoma, were severely underrepresented (8.33%). Geographically, evidence was highly concentrated in Ethiopia (29.0%) and India (25.8%), limiting generalizability. The most common independent variables were specific WASH components (e.g., sanitation, handwashing). Critical theoretical and methodological gaps were identified: 92.6% of studies lacked explicit theoretical frameworks, and most relied on cross-sectional designs, limiting causal inference. Moreover, 96.6% failed to test mediating variables, leaving mechanisms linking WASH and acute infections poorly understood.

Keywords: WASH, Child Health, Diarrhea, Stunting, Systematic Review, Acute Infections, Public Health.