Environmental Health Determinants of School WASH Programs: Epidemiological Indicators Among Learners in Rural and Urban Informal Settlements in Kenya

Abstract

Substandard Water, Sanitation, and Hygiene (WASH) infrastructure in learning institutions remains a environmental health challenge in developing nations. In Kenya, schools situated within resource challenged rural areas and urban informal settlements present built environments that alter biological exposure pathways, yet comparative evaluations of their specific health and educational tolls remain fragmented. This paper review systematically examined how physical infrastructure quality serves as a determinant for epidemiological indicators among learners in rural and urban informal settlements in Kenya. The study was anchored within the macro-level Eco-Epidemiological Model and F-Diagram of Pathogen Transmission. Following the PRISMA 2020 statement, a review protocol was executed across major electronic databases (including PubMed, CINAHL Plus, Embase, Web of Science, Scopus, Global Health, and Environment Complete) and grey literature repositories. The findings were anlysed using descriptive numerical summary and a narrative thematic analysis. The initial search identified 1,156 database publications and 31 grey literature articles. Following secondary title/abstract screening (n=187), full-text (n=52), and bibliography snowballing (n=4), a final yield of 56 studies spanning 19 Kenyan counties was synthesized. Rural schools confront severe geographic water scarcity and high microbiological contamination while urban informal settlements face extreme structural stress, with student-to-toilet ratios exceeding 100:1 and drainage overflows that increase ambient fecal contamination around schools. In both, rainy seasons and flooding trigger waste system failures and spike acute watery diarrhea outbreaks. Nationwide, poor water quality and broken hand hygiene drive gastrointestinal morbidity, while Soil-Transmitted Helminthiases (STH) show a prevalence of up to 44.05% in high-burden regions like Kakamega. Although deworming and footwear have controlled the foot-to-soil hookworm pathway, the fecal-oral pathway remains dominant, marked by high Ascaris lumbricoides intensity. In water-scarce zones, restricted water volumes prevent routine washing, leading to highly prevalent dermatological and ocular infections like scabies and trachoma. This biological toll maps directly onto educational registers, as helminthic and diarrheal infections heavily correlate with absenteeism (r=0.7523). These attendance deficits intersect with nutrition, where inconsistent school feeding programs exacerbate drops in student retention. The infrastructure deficits drive severe gender-specific impacts: adolescent girls lose up to 60 school days annually due to menstruation because roughly half of the schools lack menstrual waste disposal or water inside cubicles, and student-to-toilet ratios in ASAL areas reach up to 97:1. This violates privacy, causes stigma, and accelerates permanent dropout pathways through teenage pregnancies. The review demonstrates that school WASH facilities function as key environmental health determinants rather than mere educational amenities. To break the cycle of morbidity and absenteeism, interventions must shift from generic provisioning toward climate-resilient environmental engineering and robust local maintenance systems. It is recommended that the Kenyan Government and partners implement context-specific strategies such as water backpacks and sand dams in rural regions, and container-based sanitation with private maintenance contracts in informal settlements while coupling hardware installations with ring-fenced financing, disability-inclusive designs, and dedicated Menstrual Hygiene Management (MHM) curricula.