High frequency of HIV-1 dual infections in individuals with double transmission risk in Buenos Aires, Argentina.

G. ANDREANI, J.C. AMBROSIONI CZYRKO, M.B. BOUZAS, S.FERNÁNDEZ GIULIANO, J. BENETUCCI, J.K.CARR, L.MARTÍNEZ PERALTA.

Sydney

Congreso; 4th IAS CONFERENCE ON HIV PATHOGENESIS, TREATMENT AND PREVENTION.; 2007

International Aids Society

Objectives: Genetic characterization of HIV-1 in Argentina showed that BF recombinant form predominates among heterosexuals and injecting drug users (IDUs), while in men who have sex with men the most prevalent is subtype B . Occurrence of infection with more than one strain of HIV-1 has been described worldwide. However a systematic study has not been conducted in our country yet. The aim of this work was to investigate the presence of HIV dual infections in HIV infected individuals with double transmission risk. Methods: Informed consents and blood samples were collected from 8 HIV positive patients with double transmission risk from Buenos Aires. A partial pol HIV gene fragment was amplified by limiting dilution nested PCR from DNA isolated from buffy coat. Phylogenetic analyses were performed by the Neighbor-joining method. Bootscanning was performed to look for the presence of recombinants. Results: Dual infections were found in three out of eight patients. In the first case (IDU) two time points were analyzed, detecting the dual infection in the second sample where 22/23 sequences clustered with the CRF_12BF (the same as all the sequences from sample one) while one showed a different BF recombinant pattern. In the second patient (bisexual & IDU) 1/20 sequences clustered with subtype B while the rest showed a CRF_12BF recombinant pattern. Finally, in the third patient (bisexual) 1/14 sequences were CRF_12BF and the rest subtype B. Conclusions: These findings are in agreement with epidemiological data since BF recombinants predominated in IDUs, while bisexual risk was associated with subtype B and BF recombinants double infections. Double risk behavior increases the possibility of dual infections, which should be considered in vaccine studies.