Flood-Related Cholera Outbreak: A Case Study of Systemic Vulnerability in Nyando Sub-County, Kenya – An Analysis of Climate Change, WASH Infrastructure, and Public Health System Preparedness

Abstract Background : This case study examines the 2025 floods in Nyando Sub-County, Kisumu County, Kenya, and the resulting cholera outbreak that exposed weaknesses in the public health system. Seasonal flooding damaged sanitation facilities, contaminated water sources, and led to deaths and widespread population exposure. Methodology : The study used a qualitative case study design based on a review of publicly available Ministry of Health reports, Kisumu County surveillance data, and peer-reviewed literature. These sources were triangulated with quantitative epidemiological data to understand the outbreak trajectory and response. The SDGs and the Planetary Health framework were used to analyse the link between environmental hazards and limitations in the public health systems. Findings : Weak disease surveillance, delayed emergency response of more than 6 weeks, and inadequate preparedness worsened the outbreak. Governance challenges, including poor institutional coordination, limited funding, and weak enforcement of public health policies, hindered containment efforts. These gaps resulted in delayed interventions and reduced compliance with public health measures. The outbreak highlights the relevance of SDGs 3, 6, and 13. Conclusion : Cholera outbreaks in Nyando are structurally linked to environmental, infrastructural, and governance challenges. Addressing them requires multisectoral coordination, improved water and sanitation systems, climate resilience, and active community engagement. Information © The Authors 2026