HIV-1 diversity in Brazil

Abstract

Brazil is the largest and most populated country in South America. In fact, about 30% of the HIV-1 infected population of South and Central America and the Caribbean combined live in Brazil. This fact has epidemiologically significant consequences on the spread of HIV-1 infection and results in a different pattern of subtype frequencies in South America. The spread of HIV-1 subtypes is not only important, epidemiologically, for transmission routes, but can also be of significance in clinical settings. To gain some insight into HIV-1 diversity in Brazil, we reviewed the available molecular epidemiology data from published studies in the five geological regions of the country: north, northeast, center-west, southeast, and south. The overall results revealed a broad array of 27 genetically different HIV-1 variants consisting of five genuine subtypes, 11 circulating recombinant forms, and 11 variants with different recombinant profiles. Subtype B was dominant in all regions, followed by subclade F1 in the north, subtype C in the south, and BF1 recombinants in the northeast, center-west, and southeast regions. The elevated number of HIV-1 subtypes cocirculating as well as diverse recombinant viruses observed in this review is consistent with an old mature prior epidemic in Brazil and represents a tangible challenge for future vaccine development, as well as for the efficiency of antiretroviral treatment and diagnostic tests.