Comparison Of Plasmodium Falciparum Merozoite Surface Protein Gene Single-Nucleotide Polymorphism Along The Sino-Myanmar Border And In The Platewa Township Area Of Myanmar

Objective:This study aims to understand the polymorphism of merozoite surface protein1(Msp1)and merozoite surface protein 2(Msp2)genetic polymorphisms and epidemiology of P.falciparum from the China-myanmar border region,the Myitsone and Bhamo regions of Myanmar and the town of Platewa in Chin State of Myanmar.Method:A total of 179 blood samples were collected from malaria patients in Myitsone,Bhamo,Myanmar,and Paletwa Town,Chin State,Myanmar,to genotype P.falciparum merozoite surface protein 1(pf Msp1)and P.falciparum merozoite surface protein 2(pf Msp2)by nested PCR.Result:Msp1 and Msp2 genotypes were successfully performed in 177 samples.In these three regions,MAD20 is the most common allele in the Msp1 gene,while IC/3D7 is the most common allele in the Msp2 gene.In Myitsone district of Myanmar,MAD20 allele accounted for 88.89% of Msp1,followed by K1(64.81%),and RO33 had the lowest frequency(33.33%).In Msp2,IC/3D7 alleles accounted for 63.04%,followed by FC27(54.35%).In Bhamo district of Myanmar,the MAD20 allele was also the most common in Msp1,accounting for 85.19%,followed by K1,accounting for44.44%,and RO33,accounting for 7.41%.In Msp2,IC/3D7 allele accounted for100%,followed by FC27(29.17%).However,the genetic polymorphism of P.falciparum in Paletwa town,Chin State,Myanmar was slightly different from the previous two regions.The MAD20 allele of P.falciparum Msp1 gene was still the most common allele,accounting for 67.37%,followed by RO33,accounting for47.37%,and K1 was the least,accounting for 43.16%.In Msp2,IC/3D7 allele was dominant,accounting for 43.48%,followed by FC27,accounting for 21.74%.In Myitsone district of Myanmar,malaria infection situation was dominated by mixed infections,the infection rate was 61.11%,while in Bhamo and Paletwa Town of Myanmar,malaria infection situation was dominated by a single infection,the infection rate was 48.15% and 53.13%,respectively.Conclusion:The results showed that the dominant alleles of Msp1 in the China-Myanmar border area and the western Myanmar area were the same as MAD20,but the number of alleles K1 in the western Myanmar area was less than that of RO33,which was slightly different from the China-Myanmar border area.Statistics showed that the genotyping frequency of P.falciparum in the three regions was different,indicating that the genotyping frequency of P.falciparum in the three regions would be different with different malaria epidemic locations,suggesting that there were genetic differences in P.falciparum in the three regions.In addition,the total mixed infection rate of P.falciparum population in Tengchong area was higher than that in Bhamo and Paletwa town,and the Msp1 gene positive samples of P.falciparum in Tengchong City were mainly infected with multiple strains.Most of the Msp1 gene positive samples of P.falciparum from Bammo and Paletwa town were infected by single strains,indicating that the complexity of P.falciparum Msp1 allele combination affects the infection rate of P.falciparum in the three areas.In addition,the average MOI of P.falciparum population in Tengchong area was higher than that in Bameo and Paletwa town,indicating that the complexity of P.falciparum Msp1 alleles in these three areas also affected the transmission intensity in these three areas.In addition,there are differences in immunity between foreign and local malaria infected persons.This will provide important basic information for the study of malaria prevalence,infection diversity,malaria transmission level and malaria vaccine in these areas.