HIV dual infection with subtype B and B/F recombinant in Argentina.

A.CEBALLOS, R.RABINOVICH, G.SCARLATTI, M.LOSSO, M.WEISSENBACHER, J.CARR, L.MARTINEZ PERALTA.

Bangkok, Tailandia

Congreso; XV International Conference on AIDS; 2004

International AIDS Society

Background. Genetic characterization of HIV-1 in Argentina showed that recombinant B/F subtype was the most prevalent genetic form among heterosexual men and women and IDUs, while in men who have sex with men (MSM) subtype B is the most prevalent. However, systematic search of dual infection has not been done. The goal of this work was to investigate the presence of dual infections in HIV infected persons with double transmission risk: heterosexual and homosexual. Methods. Informed consent was obtained from 15 individuals with double transmission risk from Buenos Aires, Argentina. A blood sample was collected and a questionnaire about socio-demographic aspects and about risk assessment, was administered to the participants. RT-PCR of pol gene from plasma samples of the 15 patients was performed followed by cloning and sequencing. Phylogenetic trees and bootscanning were performed to look for the presence of recombinants. Results. Direct sequencing showed 8 patients with subtype B and 7 with B/F recombinant. For each of 15 patients 12 to 21 clones were analysed. In one of the B/F patients, a dual infection was found: subtype B (14/20 clones) and B/F recombinants (6/20 clones). This male patient was diagnosed as HIV infected in September 1990 and has been asymptomatic so far, with only some disuria and penile ulcers during the last six months, and previous episodes of gonorrhea and herpes. He declares previous heterosexual contacts but only men-to-men contacts in the last ten years. He has no history of drug use. He has been on ARV treatment since August 1995 with 2.46 log for viral load and 582 CD4/mm3. Conclusions. The analysis of dual infections is important to study the origin and evolution of HIV new recombinant forms. In Argentina there is a differential prevalence of B subtype and B/F recombinants according to the risk behavior. Therefore, double risk behavior certainly increases the possibility of dual infections with different subtype or recombinant, which should be considered in epidemiological and vaccine studies.