Wide distribution of the variant form of the human malaria parasite Plasmodium vivax

Abstract

Center for Infectious Diseases. Centers for Disease Control, Public Health Service. Department of Health and Human Service. Division of Parasitic Diseases. Malaria Branch. Atlanta, GA, USA.Center for Infectious Diseases. Centers for Disease Control, Public Health Service. Department of Health and Human Service. Division of Parasitic Diseases. Malaria Branch. Atlanta, GA, USA.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Papua New Guinea Institute of Medical Research. Madang, PNG.Center for Infectious Diseases. Centers for Disease Control, Public Health Service. Department of Health and Human Service. Division of Parasitic Diseases. Malaria Branch. Atlanta, GA, USA.We have found polymorphism in the repetitive and nonrepetitive regions of the sporozoite vaccine antigen, the circumsporozoite (CS) protein, in Plasmodium vivax malaria parasites from two geographically distant malaria endemic regions of the world. Like the recently described variant repeat sequence of P. vivax from Thailand, the CS protein repeat sequence of the variant P. vivax parasites from Papua New Guinea and Brazil is ANGA(G/D)(N/D)QPG, which differs from the previously identified CS repeat sequence, GDRA(D/A)GQPA, of P. vivax parasites from South America, Central America, and North Korea. Comparison of the P. vivax CS protein outside the repeat region revealed restricted polymorphism in regions that have exhibited T-cell immune function and sequence heterogeneity in the CS protein of Plasmodium falciparum. Our results show that P. vivax malaria parasites with the variant CS repeat sequences are widespread in nature and that the polymorphism in the CS protein of P. vivax is also present in the nonrepeat region