How health systems factors, socioeconomic status, and care-seeking practices influence the cost of rotavirus-related diarrhea care in Mukuru informal settlements, Kenya.

Background: Diarrheal diseases remain a leading cause of death, especially in Africa, accounting for 1.17 million deaths globally in 2021, with rotavirus responsible for 32.2% of these deaths. Since the introduction of rotavirus vaccines in Kenya in 2014, several studies have demonstrated the clinical impact of the vaccine, showing a reduction in child deaths from diarrhea. However, limited evidence exists on the socioeconomic burden that is still posed by rotavirus diarrhea, especially in Kenya, where the prevalence remains high at 14%, as reported in the 2022 Kenya Demographic and Health Survey. The persistence of diarrheal burden and hospitalizations despite investments in diarrheal prevention and control suggests that medical and public health interventions do not automatically reduce the health burden and related economic burden and require the integration of policies that address other socioeconomic determinants of health demand. This study sought to investigate how health-seeking patterns and socioeconomic status intersect and influence the cost burden of diarrheal illnesses in Mukuru informal settlements in Kenya. Methods: A cross-sectional study was conducted between May 2023 and July 2025 among caregivers of children under five presenting with diarrhea at Mukuru clinics. Of the 500 diarrheal cases, 100 laboratory-confirmed rotavirus cases were analyzed. Costs were categorized as direct medical, direct non-medical, and indirect costs. Descriptive and stratified analyses were used to explore cost variations by socioeconomic status and care-seeking behavior. A gamma regression model assessed associations between the cost of illness and predictors including education, employment, prior care-seeking, and type of facility visited. Results: The average cost of treating a diarrheal episode was estimated at $8.88 (95% CI: 7.25, 10.51) per patient. Direct medical costs comprised 60.36% of this cost and were mainly driven by drug prescriptions purchased outside clinics (30.18%), expenditure at other facilities on self-medication (19.37%), and expenditure at Mukuru clinics (10.81%). Income lost through work absence or leisure accounted for 36.82% at an average cost of $3.17 (95%:2.95, 3.58). Fragmented care pathways, drug stockouts, delayed care seeking, and inappropriate self-medication significantly increased household costs, regardless of insurance status. Employment status and type strongly influenced indirect costs, aggravated by long waiting times and repeated care-seeking. Conclusion: Overall, the findings indicate that the cost of childhood diarrhea in Mukuru is driven less by caregiver socioeconomic characteristics-given that Mukuru residents share similar vulnerabilities-and more by health-seeking behavior and health system factors, particularly drug availability and fragmented care pathways. Strengthening drug supply chains, improving the quality and reliability of public primary healthcare, and promoting timely and proper care-seeking pathways could substantially reduce household costs and improve financial protection in urban informal settlements.