Plasmodium vivax infection in Anajás, State of Pará: no differential resistance profile among Duffy-negative and Duffy-positive individuals (original) (raw)

Background There is large body of evidence that states that invasion of Plasmodium vivax requires the Duffy antigen, but the universality of this specificity is certainly now under question with recent reports showing that in some parts of the world P. vivax infects and causes disease in Duffy-negative people. These findings reinforce the idea that this parasite is rapidly evolving, being able to use other receptors than Duffy to invade the erythrocytes, which may have an enormous impact in P. vivax current distribution. The presence of P. vivax infection in Duffy-negative individuals was investigated in a cross-sectional study conducted in Anajás, Archipelago of Marajó, State of Pará, which is an area of malaria transmission in the Brazilian Amazonia. Methods Duffy genotyping and Plasmodium species diagnostic assays were performed successfully in 678 individuals. An allele-specific primer polymerase chain reaction (PCR) technique was used for Duffy blood group genotyping. Identific...