title: Plasmodium falciparum populations from northeastern Myanmar display high levels of genetic diversity at multiple antigenic loci.
abstract: Levels of genetic diversity of the malaria parasites and multiclonal infections are correlated with transmission intensity. In order to monitor the effect of strengthened malaria control efforts in recent years at the China-Myanmar border area, we followed the temporal dynamics of genetic diversity of three polymorphic antigenic markers msp1, msp2, and glurp in the Plasmodium falciparum populations. Despite reduced malaria prevalence in the region, parasite populations exhibited high levels of genetic diversity. Genotyping 258 clinical samples collected in four years detected a total of 22 PCR size alleles. Multiclonal infections were detected in 45.7% of the patient samples, giving a minimum multiplicity of infection of 1.41. The majority of alleles experienced significant temporal fluctuations through the years. Haplotype diversity based on the three-locus genotypes ranged from the lowest in 2009 at 0.33 to the highest in 2010 at 0.80. Sequencing of msp1 fragments from 36 random samples of five allele size groups detected 13 different sequences, revealing an additional layer of genetic complexity. This study suggests that despite reduced prevalence of malaria infections in this region, the parasite population size and transmission intensity remained high enough to allow effective genetic recombination of the parasites and continued maintenance of genetic diversity.
authors.affiliation: Department of Parasitology, Kunming Medical University, Kunming, Yunnan Province, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Yuan
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: Lanou
authors.initials: L
authors.lastname: Wu
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Li
authors.forename: Daniel
authors.initials: D
authors.lastname: Parker
authors.forename: Shuhui
authors.initials: S
authors.lastname: Xu
authors.forename: Yousheng
authors.initials: Y
authors.lastname: Zhao
authors.forename: Guohua
authors.initials: G
authors.lastname: Feng
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Guiyun
authors.initials: G
authors.lastname: Yan
authors.forename: Qi
authors.initials: Q
authors.lastname: Fan
authors.forename: Zhaoqing
authors.initials: Z
authors.lastname: Yang
authors.forename: Liwang
authors.initials: L
authors.lastname: Cui
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000953:Antigens, Protozoan / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D060085:Coinfection / Q000453:epidemiology / Q000469:parasitology; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000469:parasitology*; D008297:Male; D020066:Merozoite Surface Protein 1 / Q000235:genetics; D008875:Middle Aged; D002052:Myanmar / Q000453:epidemiology; D010963:Plasmodium falciparum / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D015995:Prevalence; D015800:Protozoan Proteins / Q000235:genetics; D055815:Young Adult
chemical_list: D000953:Antigens, Protozoan; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; C065974:merozoite surface protein 2, Plasmodium; C072492:glutamate-rich protein, Plasmodium