HIV dual infection with subtype B and recombinant BF in Argentina.

A.CEBALLOS; G.ANDREANI; R.D.RABINOVICH; G.SCARLATTI; M.LOSSO; M.WEISSENBACHER ; J.CARR; L.MARTÍNEZ PERALTA.

Río de Janeiro, Brasil

Conferencia; 3rd IAS CONFERENCE ON HIV PATHOGENESIS AND TREATMENT; 2005

International AIDS Society

Introduction: Genetic characterization of HIV-1 in Argentina showed that recombinant B/F subtype was the most prevalent genetic form among heterosexual persons and IDUs, while in men who have sex with men subtype B is the most prevalEml. The aim of this work was to investigate the presence of dual infections in HIV-infected persons with double transmission risk (heterosexual and homosexual). Methods: Blood sample were collected from 15 indíviduals with double transmission risk from Buenos Aires. A partial pol HIV gene fragment was cloninig after RT-PCR from plasma samples. Phylogenetic analysis were performed with the Neighbor-joining method. Bootscanning was performed to look for the presence of recombinants. Results: Direct sequencing showed 8 patients with subtype B and 7 with B/F recombinanl. For each of 15 patients 12 to 21 cloneswere analysed. In a patient with subtype B, a dual infection was found: subtype B (19/20 clones) and B/F recombinant (1/20 clones) in a sample (T1). In another sample (T2=two years later) all the 20 clones analysed corresponded to subtype B. T1 sequences formed a cluster separated from T2 sequences in the phylogenetic tree. Analysis of divergence suggested that T2 sequences were not due to a new dual infection with another B variant, because the genetic distances between the 19 Ti B sequences and 20 T2 sequences were: 1,8% and between T1 or T2 and other Argentine sequences of subtype B were close to 5%. This male patient was diagnosed as HIV-infected in 1990. He had no history of drug use. Conclusions: A dual infection was shown with predominance of subtype B in both samples studied. This findings are in agreement with epidemiological data since the patient declared previous heterosexual contacts but only men-to-men contacts in the last ten years. Double risk behavior ¡ncreases the possibility of dual ¡nfections, which should be considered in vaccine studies.