Temporal Changes in the Genetic Diversity of Merozoite Surface Protein-1 in Myanmar.

Despite a significant decline in the incidence of malaria in Myanmar recently, malaria is still an important public health concern in the country. Although is associated with the highest incidence of malaria in Myanmar, the proportion of cases has shown a gradual increase in recent years. The genetic diversity of merozoite surface protein-1 block 5-6 (- ICB 5-6) in the population of Myanmar was analyzed to obtain a comprehensive insight into its genetic heterogeneity and evolutionary history. High levels of genetic diversity of - ICB 5-6 were identified in the isolates collected from Myanmar between 2013 and 2015. Thirty-nine distinct haplotypes of - ICB 5-6 (13 for Sal I type, 20 for recombinant type, and 6 for Belem type) were found at the amino acid level. Comparative analyses of the genetic diversity of - ICB 5-6 sequences in the recent (2013-2015) and the past (2004) populations in Myanmar revealed genetic expansion of the - ICB 5-6 in recent years, albeit with a declined incidence. The recent increase in the genetic heterogeneity of Myanmar - ICB 5-6 is attributed to a combination of factors, including accumulated mutations and recombination. These results suggest that the size of the population in Myanmar is sufficient to enable the generation and maintenance of genetic diversity, warranting continuous molecular surveillance of genetic variation in Myanmar .