Expansion of HIV BF recombinants among men who have sex with men (MSM) in Buenos Aires, Argentina

PANDO MA; MARONE R; BALAN I; CARBALLO DIEGUEZ A; AVILA MM

Paris

Conferencia; 9th IAS Conference on HIV Science (IAS 2017); 2017

IAS

Objective: SeveralHIV epidemiological studies performed among MSM from Buenos Aires, Argentina revealedhigh HIV prevalence (11-17%) and incidence (4.5 per 100 persons-year). Firststudies on molecular epidemiology established that subtype B dominated theepidemic among MSM while BF recombinants were more frequent among heterosexualmen and women. The objective of the study was to describe the subtype diversityof HIV among MSM along 10 years of epidemiological studies in Buenos Aires,Argentina (2000-2009). Methods: Fourdifferent studies were performed from 2000 to 2009 (Study 1, 2, 3 and 4). Allthe studies included self-reported MSM, including those who have other partners(women and/or transgender) and those who exclusively have male partners. HIV DNA/RNAwas isolated from cells/plasma samples using commercial kits and pol gene was amplified from positions2143 to 3798 (HXB2 numbering) and sequenced in an automatic sequencer. Thephylogenetic analysis was performed by Neighbor-joining and bootscanning. Results: Atotal of 293 pol gene sequences were obtainedand phylogenetic analysis revealed that 221 (75.4%) were subtype B and 72 wereBF recombinants (24.6%). Temporal analysis demonstrated that frequency of subtypeB significantly decreased over time: 89.6% in Study 1, 83.3% in Study 2, 71.2%in Study 3 and 58.5% in Study 4 (p<0.001). In the last study, the frequencyof subtype B was significantly higher among men who exclusively have sex withmen as compared with those also having sex with women and/or trans (74.1% vs. 42.3%, p=0.027). Conclusions: SubtypeB continues being predominant among MSM, however, in comparison to previousstudies, the frequency of BF recombinants is increasing over time. Our resultssuggest that even subtype B might have been the subtype that originated the HIVepidemic among MSM, the interconnection with other groups where BF recombinantspredominate, has produced a change in the molecular epidemiology of MSM. Thisfact needs to be considered for any preventive clinical trial to be conductedamong MSM, where HIV subtype could be influencing the result.