Epidemiological Analysis of Cholera Outbreaks and Environmental Risk Factors in Adamawa State, North East Nigeria, 2019 to 2024

Cholera outbreaks remain a recurrent environmental health emergency in North East Nigeria, driven by complex interactions between inadequate water and sanitation infrastructure, displacement, and climate variability. This study conducted a retrospective epidemiological analysis of cholera outbreaks in Adamawa State between 2019 and 2024, integrating outbreak surveillance data with environmental risk factor mapping. Attack rate, case fatality rate, and spatial distribution of cholera episodes were analyzed using data obtained from the Adamawa State Ministry of Health and Nigeria Centre for Disease Control. Environmental risk factor data, including water source quality, sanitation coverage, flood occurrence records, and rainfall patterns, were obtained from state and LGA databases and linked to outbreak data using Geographic Information System mapping. Results showed that seven outbreak episodes occurred in the study period, with cumulative cases exceeding 4,200 and a mean case fatality rate of 2.8 percent. Outbreak epicenters were consistently located in communities with open defecation rates above sixty percent and piped water coverage below twenty percent. Flood events preceded seventy-one percent of outbreak onsets by four to twelve days. Internally displaced persons settlements were disproportionately affected. Seasonal clustering in the wet season was statistically significant. The study fills an analytical gap in documenting environmental drivers of recurrent cholera outbreaks at sub-national level in Nigeria. Recommendations include pre-outbreak WASH emergency preparedness, flood-sensitive disease early warning systems, and targeted sanitation improvement in high-risk communities. Keywords: cholera, outbreak analysis, environmental risk factors, Adamawa State, surveillance.