Meteorological Conditions Associated with Meningitis Epidemic Seasons in Nigeria’s Meningitis Belt

Bacterial meningitis epidemics in sub-Saharan Africa are closely associated with specific meteorological conditions prevailing during the dry season, forming a well-documented relationship between climate and infectious disease dynamics. This study investigates the meteorological conditions associated with meningococcal meningitis epidemic seasons across Nigeria's meningitis belt, encompassing states in the North West and North East zones. Meteorological data, including relative humidity, temperature, dust aerosol concentration, and wind direction, were compiled from NiMet synoptic stations in Sokoto, Gusau, Katsina, and Maiduguri for the period 2015 to 2023. Epidemic case data were obtained from the Nigeria Centre for Disease Control (NCDC) weekly epidemiological bulletins. Logistic regression analysis was applied to identify the meteorological predictors most strongly associated with weeks of epidemic-level incidence, defined as exceeding the WHO alert threshold of 10 cases per 100,000 population per week. Results confirm that relative humidity below 30 percent, maximum daily temperatures above 37 degrees Celsius, and elevated Aerosol Optical Depth values are the strongest independent predictors of epidemic activity. A composite meteorological epidemic risk index combining these three variables correctly classifies epidemic versus non-epidemic weeks with 78 percent accuracy. Recommendations include integration of the epidemic risk index into NCDC surveillance tools and NiMet health advisory services for proactive vaccine pre-positioning. Keywords: meningitis, meteorological conditions, Nigeria, epidemic, relative humidity.