Reassessing the origin of the HIV-1 CRF02_AG lineages circulating in Brazil
Published in AIDS research and human retroviruses, 2015
Recommended citation: Delatorre E, Velasco-De-Castro CA, Pilotto JH, Couto-Fernandez JC, Bello G, Morgado MG. Reassessing the Origin of the HIV-1 CRF02_AG Lineages Circulating in Brazil. AIDS Res. Hum. Retroviruses. 2015 Dec;31(12):1230–7.
Abstract
HIV-1 CRF02-AG is responsible for at least 8% of the HIV-1 infections worldwide and is distributed mainly in West Africa. CRF02-AG has recently been reported in countries where it is not native, including Brazil. In a previous study including 10 CRF02-AG Brazilian samples, we found at least four independent introductions and two autochthonous transmission networks of this clade in Brazil. As more CRF02-AG samples have been identified in Brazil, we performed a new phylogeographic analysis using a larger dataset than before. A total of 20 Brazilian (18 from Rio de Janeiro and two from Sao Paulo) and 1,485 African HIV-1 CRF02-AG pol sequences were analyzed using maximum likelihood (ML). The ML tree showed that the Brazilian sequences were distributed in five different lineages. The Bayesian phylogeographic analysis of the Brazilian and their most closely related African sequences (n=212) placed the origin of all Brazilian lineages in West Africa, probably Ghana, Senegal, and Nigeria. Two monophyletic clades were identified, comprising only sequences from Rio de Janeiro, and their date of origin was estimated at around 1985 (95% highest posterior density: 1979-1992). These results support the existence of at least five independent introductions of the CRF02-AG lineage from West Africa into Brazil and further indicate that at least two of these lineages have been locally disseminated in the Rio de Janeiro state over the past 30 years.
