title: Genetic diversity of Plasmodium vivax over time and space: a community-based study in rural Amazonia.
abstract: To examine how community-level genetic diversity of the malaria parasite Plasmodium vivax varies across time and space, we investigated the dynamics of parasite polymorphisms during the early phases of occupation of a frontier settlement in the Amazon Basin of Brazil. Microsatellite characterization of 84 isolates of P. vivax sampled over 3 years revealed a moderate-to-high genetic diversity (mean expected heterozygosity, 0.699), with a large proportion (78.5%) of multiple-clone infections (MCI), but also a strong multilocus linkage disequilibrium (LD) consistent with rare outcrossing. Little temporal and no spatial clustering was observed in the distribution of parasite haplotypes. A single microsatellite haplotype was shared by 3 parasites collected during an outbreak; all other 81 haplotypes were recovered only once. The lowest parasite diversity, with the smallest proportion of MCI and the strongest LD, was observed at the time of the outbreak, providing a clear example of epidemic population structure in a human pathogen. Population genetic parameters returned to pre-outbreak values during last 2 years of study, despite the concomitant decline in malaria incidence. We suggest that parasite genotyping can be useful for tracking the spread of new parasite strains associated with outbreaks in areas approaching malaria elimination.
authors: Department of Parasitology, Institute of Biomedical Sciences,University of São Paulo,Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP,Brazil.
authors: Camilla L
authors: CL
authors: Batista
authors: Department of Parasitology, Institute of Biomedical Sciences,University of São Paulo,Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP,Brazil.
authors: Susana
authors: S
authors: Barbosa
authors: Department of Parasitology, Institute of Biomedical Sciences,University of São Paulo,Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP,Brazil.
authors: Melissa
authors: M
authors: Da Silva Bastos
authors: Department of Parasitology, Institute of Biomedical Sciences,University of São Paulo,Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP,Brazil.
authors: Susana Ariane S
authors: SA
authors: Viana
authors: Department of Parasitology, Institute of Biomedical Sciences,University of São Paulo,Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP,Brazil.
authors: Marcelo U
authors: MU
authors: Ferreira
mesh_terms: D001938:Brazil / Q000453:epidemiology; D015331:Cohort Studies; D014644:Genetic Variation; D006239:Haplotypes; D006801:Humans; D015994:Incidence; D016780:Malaria, Vivax / Q000453:epidemiology / Q000469:parasitology*; D018895:Microsatellite Repeats; D010966:Plasmodium vivax / Q000235:genetics* / Q000502:physiology; D012424:Rural Population; D013997:Time Factors
keywords: Amazonia