Plasmodium falciparum genetic diversity and multiplicity of infection among asymptomatic and symptomatic malaria-infected individuals in Uganda

Abstract

Background: Plasmodium falciparum remains a significant public health challenge globally, especially in sub-Saharan Africa, where it accounts for 99% of the disease burden. Infection outcomes vary widely from asymptomatic to severe, influenced by factors such as parasite genetic diversity and multiplicity of infection (MOI). This study utilized seven neutral microsatellite markers to investigate Plasmodium falciparum genetic diversity and MOI in both asymptomatic and symptomatic individuals in Uganda. Methods: This cross-sectional study analyzed 225 isolates from asymptomatic and symptomatic malaria patients (ages 6 months to ≥18 years). Genetic diversity and multiplicity of infection (MOI) of Plasmodium falciparum were assessed using seven microsatellite markers. STATA ver 17 and genetic analysis software were used for data analysis. Results: Plasmodium falciparum exhibited high genetic diversity in both asymptomatic and symptomatic infections. The mean expected heterozygosity (He) ranged from 0.798 (95% CI: 0.75-0.84) in symptomatic uncomplicated cases to 0.809 (95% CI: 0.77-0.85) in asymptomatic cases. MOI did not significantly differ (p = 0.3342) between asymptomatic and symptomatic infections, with mean MOI ranging from 1.92 (95% CI: 1.61–2.23) in symptomatic complicated cases to 2.10 (95% CI: 1.83–2.37) in asymptomatic cases. Polyclonal infections were prevalent, varying from 58.4% (95% CI: 44.60-72.39) to 63% (95% CI: 51.22-74.78) across malaria infection categories. Conclusion:There is a high level of Plasmodium falciparum genetic diversity and MOI in Uganda. Asymptomatic carriers host harbor diverse parasites, posing challenges for malaria control and necessitating targeted interventions for effective strategies.