Rainfall, Temperature Variability and Malaria Incidences in Suba-North, Homabay County, Kenya

Abstract

Purpose: Climate variability affects malaria transmission, yet its local contribution remains unclear. This study evaluated the effects of rainfall and temperature variability on malaria incidence in Suba-North Sub-County, Homabay County, Kenya from 1994-2023. Climatic data were obtained from ICIPE Mbita Weather Station while malaria data were obtained from the Ministry of Health and selected health facilities. Methodology: Data were analysed using descriptive statistics, Pearson correlation and Poisson regression. Findings: Findings showed irregular temperature patterns ranging from 24.63°C to 26.35°C and high rainfall variability, peaking at 255.77 mm in 1997. Malaria morbidity varied, lowest in 2002 (2.4%) and highest in 2005 (4.03%). Rainfall and temperature explained about 32% of malaria variation in some periods (2004-2014) but relationships were inconsistent. Unique Contribution to Theory, Policy and Practice: The study recommends integrated control: ITNs, IRS, vaccination and climatic monitoring. This study provides the first 30-year (1994-2023) empirical analysis for Suba-North using ICIPE Mbita station data combined with 7 health facilities and that of government offices, extending the Environmental Determinants of Health Theory by showing climate effects are mediated by intervention coverage, informing climate-based early warning systems and targeted protection of vulnerable groups (children under 5 and females).