Malaria remains a major public health challenge in Nigeria, with parasite genetic diversity posing significant obstacles to effective control and vaccine development. This study investigated the seasonal variation in prevalence and genetic diversity of Plasmodium falciparum isolates in Kogi State, North-Central Nigeria, using polymorphic markers of merozoite surface protein 1 (MSP-1) and merozoite surface protein 2 (MSP-2).
A total of 3,669 participants were enrolled between 2021 and 2023 across selected Local Government Areas in the three geopolitical zones of Kogi State. Of these, 1,834 (50.0%) tested positive for P. falciparum by rapid diagnostic test and microscopy. Malaria prevalence was higher during the wet season (52.9%) compared to the dry season (47.0%), with Kogi East recording the highest burden across seasons. Children aged 1–10 years exhibited the highest prevalence (75.4%), and infection rates varied significantly across Local Government Areas.
Genotyping revealed the presence of all three MSP-1 allelic families (K1, MAD20, and RO33) and two MSP-2 families (FC27 and 3D7). FC27 and 3D7 were the predominant MSP-2 alleles across zones and seasons. Multiplicity of infection ranged from 1.0 to 1.3, indicating low to moderate clonal diversity. The expected heterozygosity (He) was 0.56 for MSP-1 and 0.84 for MSP-2, demonstrating greater genetic diversity at the MSP-2 locus.
The findings reveal seasonal and geographical variation in malaria prevalence and substantial genetic diversity of circulating P. falciparum strains in Kogi State. These population-based genetic data provide valuable insights for malaria control strategies and vaccine development efforts in North-Central Nigeria.