Genetic diversity of Plasmodium falciparum infection among children with uncomplicated malaria living in Pointe-Noire, Republic of Congo

Abstract

Introduction: molecular characterization of malaria parasites from different localities is important to improve understanding of acquisition of natural immunity to Plasmodium falciparum, to assist in identifying the most appropriate strategies for control and to evaluate the impact of control interventions. This study aimed to determine the genetic diversity and the multiplicity of infection in Plasmodium falciparum isolates from Pointe-Noire, Republic of Congo.

Methods: Plasmodium falciparum isolates were collected from 71 children with uncomplicated malaria; enrolled into the study for evaluating the therapeutic efficacy of artemether-lumefantrine combination. Both msp-1 and msp-2 genes were genotyped.

Results: from 296 distinct fragments detected, 13 msp-1 and 27 msp-2 different alleles were identified. For msp-1, RO33 family was poorly polymorphic. The K1 family has shown the trend of predominance (41%), followed by Mad20 (35%). Comparatively to msp-2, 49.6% and 48.8% fragments belonged to 3D7 and FC27 respectively. Taking together msp-1 and msp-2 genes, the overall multiplicity of infection has been increased to 2.64 and 86% harbored more than one parasite genotype. Parasite density was not influenced by age as well as the multiplicity of infection which was not influenced neither by age nor by parasite density.

Conclusion: genetic diversity of Plasmodium falciparum in isolates from patients with uncomplicated malaria in Pointe-Noire is high and consisted mainly of multiple clones. The overall multiplicity of infection has been largely increased when considering msp-1 and msp-2 genes together. With the changes in malaria epidemiology, the use of both msp-1 and msp-2 genes in the characterization of Plasmodium falciparum infection is recommended.