Recurrent Parasitemias and Population Dynamics of Plasmodium vivax Polymorphisms in Rural Amazonia

Autor(es)

Orjuela-Sanchez, Pamela ^[1] ; da Silva, Natal Santos ^[1] ; da Silva-Nunes, Monica ^{[1, 2]} ; Ferreira, Marcelo Urbano ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Parasitol, BR-05508900 Sao Paulo - Brazil

^[2] Univ Fed Acre, Dept Hlth Sci, BR-69915900 Rio Branco, AC - Brazil

• Tipo de documento: Artigo Científico
• Fonte: American Journal of Tropical Medicine and Hygiene; v. 81, n. 6, p. 961-968, DEC 2009.
• Citações Web of Science: 53

Resumo

Clinical trials documented alarming post-treatment Plasmodium vivax recurrence rates caused by recrudescence of surviving asexual blood stages, relapse from hypnozoites, or new infections. Here we describe high rates of P vivax recurrence (26-40% 180 days after treatment) in two cohorts of rural Amazonians exposed to low levels of malaria transmission after a vivax malaria episode treated with chloroquine-primaquine. Microsatellite analysis of 28 paired acute infection and recurrence parasites showed only two pairs of identical haplotypes (consistent with recrudescences or reactivation of homologous hypnozoites) and four pairs of related haplotypes (sharing alleles at 11-13 of 14 microsatellites analyzed). Local isolates of P vivax were extraordinarily diverse and rarely shared the same haplotype, indicating that frequent recurrences did not favor the persistence or reappearance of clonal lineages of parasites in the Population. This fast haplotype replacement rate may represent the typical population dynamics Of neutral polymorphisms in parasites from low-endemicity areas. (AU)

• Processo FAPESP: 07/51199-0 - Diversidade genetica, estrutura populacional e dinamica de transmissao de plasmodium vivax na amazonia rural brasileira.
• Beneficiário: Marcelo Urbano Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular