Comparative Analysis of P. vivax Merozoite Surface Protein-1 Genetic Diversity in Multiple Geographical Regions

Despite decreases in incidence, malaria remains a serious infectious disease, with the Plasmodium vivax (P. vivax) species being the predominant cause, accounting for about 90% of annual reported cases in Iran. In this study, we describe the genetic diversity of the P. vivax merozoite surface protein-1 (Pvmsp-1) across three geographical locations to evaluate the impact of this diversity on disease control. A total of 88 P. vivax samples were collected from three neighboring countries: Iran, Pakistan, and Afghanistan, during 2015-2016. Genomic DNA was extracted, and fragments of Pvmsp-1 were amplified and sequenced. The nucleotide and amino acid changes, as well as the haplotype frequency in Pvmsp-1, were analyzed across these geographic sites. The sequences of Pvmsp-1 obtained from the studied regions were compared with homologous sequences from the GenBank database to explore the genetic structure of P. vivax. The PCR products of the Pvmsp-1 gene, using Pvmsp-1 specific primers, showed a 1124 bp long band. Genotyping of the Pvmsp-1 gene revealed the presence of three allele types, with type 1 being predominant. Most of the polymorphisms were found within the 400-600 bp regions. Some of the Iranian P. vivax isolates showed 98% similarity in their identity compared to other strains. The study of genetic diversity distribution in P. vivax provides crucial information for malaria control and elimination programs. Despite the high homology among these geographical regions and the different haplotypes between Iranian and other samples, it can be concluded that malaria transmission in this investigation is local to Iran.