Differential subtypes of HIV and hepatitis B virus (HBV) are prevalent among injecting drug users (IDUs) and men who have sex with men (MSM) in Buenos Aires, Argentina.

L. MARTINEZ PERALTA, J. TRINKS, M.L. CUESTAS, V.L. MATHET, M. SEGURA, M.M. AVILA, M.C.WEISSENBACHER, J.R. OUBIÑA.

Toulon

Congreso; 15th ISHEID (International Symposium on HIV and Emerging Infectious Diseases). 28-30 de Mayo de 2008; 2008

Introduction: In Buenos Aires, molecular studies suggest that B/F recombinants are the most common HIV-1 subtypes circulating among the heterosexual and injecting drug users (IDUs) populations, while subtype B predominates among men who have sex with men (MSM). A previous study (2004) has revealed that HBV/D and HBV/F prevail among blood donors. Materials and Methods: During the period 2000-2003, blood samples from two high-risk groups residing in Buenos Aires city and its surrounding areas were analyzed for HBV and HIV. HBV genotypes were assigned in 22 IDUs samples and 14 MSM by PCR amplification followed by RFLP and confirmed by nucleotide sequencing of two different coding regions (S and PreC/C region). As already published, HIV genotypes were assigned by nucleotide sequencing: full length HIV-1 genome sequencing was performed in 9 HIV-1 MSM recent seroconversions (2003) and sequences of a region of gag, pol and vpu genes were analysed in 21 HIV positives samples of IDUs (2001). HBV/A prevailed among IDUs (81.8%) while HBV/F was predominant among MSM (57.1%). The high predominance of HBV/A among IDUs is in sharp contrast to its low prevalence among blood donors (P=0.0006) and MSM (P>=0.0137). Complete sequencing of the 9 HIV-1 incident MSM samples, showed a 78% subtype B, and 22.0% subtype B/F predominance. All IDUs HIV positive samples were B/F recombinants. Data suggest that, during 2000-2003, two simultaneous and independent HIV and HBV epidemics took place in Buenos Aires: one spreading among IDUs (HIV-1: B/F recombinants; HBV: genotype A) and another one among MSM (HIV-1: subtype B; HBV: genotype F).