Spatiotemporal Dynamics of Malaria Incidence and Climatic Variability Across the Six Area Councils of the Federal Capital Territory, Abuja: Implications for Defining the Malaria Transmission Season

Abstract

Malaria remains a major public health challenge in Nigeria, and its transmission is strongly influenced by climatic and environmental conditions. Variations in temperature and rainfall can affect mosquito breeding, parasite development and the seasonal distribution of malaria. Understanding these relationships is important for improving malaria surveillance and determining the appropriate timing of control interventions. This study examined the relationship between climatic variables and malaria incidence in the Federal Capital Territory (FCT), Abuja.The study employed a retrospective ecological approach using monthly malaria incidence data obtained from one health facility in each of the six Area Councils of the FCT. Data covering the period 2020–2022 were examined to determine temporal and spatial patterns of malaria occurrence. Longer-term malaria incidence data were also examined using annual malaria incidence estimates and population projections. Climatic variables, particularly rainfall and temperature, were considered in assessing variations in malaria incidence. Malaria incidence was expressed in relation to population size to facilitate comparison among the Area Councils. The findings demonstrated considerable temporal and spatial variation in recorded malaria incidence across the FCT. Most Area Councils exhibited a recurring pattern of increased malaria incidence in February and August, followed by lower recorded incidence during November, December and January. The highest incidence occurred in August in 2020 and 2021, whereas the peak shifted to September in 2022, suggesting interannual variability in the timing of peak malaria transmission. Gwagwalada recorded an unusual pattern of relatively low malaria incidence in 2020, which may have been influenced by reduced healthcare utilization associated with the use of the University of Abuja Teaching Hospital as a major COVID-19 treatment centre. In 2021, the National Hospital in AMAC recorded substantially higher malaria cases than the other study facilities. The longer-term analysis also indicated an overall increase in malaria incidence, with AMAC showing a particularly pronounced increase. The observed seasonal patterns were broadly consistent with the established influence of climatic conditions, particularly rainfall and temperature, on malaria transmission. Climate-informed malaria early-warning systems, strengthened surveillance and Area Council-specific interventions are recommended to support more effective malaria prevention and control in the FCT.