Age-Dependent Acquisition of Protective Immunity to Malaria in Riverine Populations of the Amazon Basin of Brazil

Autor(es)

Ladeia-Andrade, Simone ^[1] ; Ferreira, Marcelo Urbano ^[2] ; de Carvalho, Maria Esther ^[1] ; Curado, Izilda ^[1] ; Coura, Jose Rodrigues ^[1]

Afiliação do(s) autor(es)

^[1] Superintendency Control Endemies, Lab Seroepidentiol, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Biomed Sci, Dept Parasitol, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: American Journal of Tropical Medicine and Hygiene; v. 80, n. 3, p. 452-459, MAR 2009.
• Citações Web of Science: 66

Resumo

Five community-based cross-sectional surveys of malaria morbidity and associated risk factors in remote riverine populations in northwestern Brazil showed average parasite rates of 4.2% (thick-smear microscopy) and 14.4% (polymerase chain reaction {[}PCR]) in the overall population, with a spleen rate of 13.9% among children 2-9 years of age. Plasmodium vivax was 2.8 times more prevalent than P. falciparum, with rare instances of P. malariae and mixed-species infections confirmed by PCR; 9.6% of asymptomatic subjects had parasitemias detected by PCR. Low-grade parasitemia detected by PCR only was a risk factor for anemia, after controlling for age and other covariates. Although clinical and subclinical infections occurred in all age groups, the risk of infection and disease decreased significantly with increasing age, after adjustment for several covariates in multilevel logistic regression models. These findings suggest that the continuous exposure to hypo- or mesoendemic malaria may induce significant anti-parasite and anti-disease immunity in native Amazonians. (AU)

• Processo FAPESP: 05/51988-0 - Epidemiologia da malaria: fatores de risco, distribuicao espaco-temporal e resposta ao tratamento em uma coorte rural amazonica.
• Beneficiário: Marcelo Urbano Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular