Merozoite surface protein 2 polymorphism of Plasmodium falciparum isolates in a selected malarious area of Northwest Ethiopia

Abstract

Background The genetic diversity of Plasmodium falciparum provides the parasite with many effective immune evasion and drug resistance mechanisms. This phenomenon is a major problem in eradicating malaria globally. This study aimed to assess merozoite surface protein 2 polymorphisms in P. falciparum isolates from Northwest Ethiopia. Method A cross-sectional study was conducted to assess merozoite surface protein 2 polymorphisms in P. falciparum isolates from selected malarious areas in Northwest Ethiopia from April to June 2021. A convenience sampling technique was used to select a total of 150 study participants. A finger prick blood sample was collected for the preparation of blood films and dried blood spots for molecular genotyping. The Merozoite surface protein 2 allele frequency and multiplicity of infection were computed. Spearman's rank coefficients were used to assess the associations between the multiplicity of infection and parasite density and age. A P value < 0.05 was considered to indicate statistical significance. Result Polymorphism analysis was performed on 126 P. falciparum isolates. There were 38 different merozoite surface protein 2 alleles, 20 of which corresponded to the IC/3D7 allelic family and 18 to the FC27 allelic family. The majority of the isolates contained multiple infections, and the mean multiplicity of infection was 3.46. There was no statistically significant difference in the multiplicity of infection in relation to the age of patients (P = 0.646). However, a statistically significant correlation was found between parasite density and the multiplicity of infection (P = 0.046). The heterozygosity index for merozoite surface protein 2 was 0.948. Conclusion This study showed that P. falciparum isolates contain multiple genotypes with a high multiplicity of infections, suggesting the presence of extensive genetic diversity and mixed-strain infections. This could reflect a high level of malaria transmission intensity, which requires more effort to control malaria transmission in the study area.