Surveillance of HIV-1 subtypes in Buenos

A. GOMEZ,; D. DILERNIA,; L. LOURTAU,; M. LOSSO,; H. SALOMON; M. GÓMEZ CARRILLO

Toronto, Canadá

Conferencia; XVI International AIDS Conference,; 2006

International AIDS Society

Background: We have previously reported a high prevalence of unusual African/Asian “nonB-nonBF” HIV variants in Argentina (IAS2005 Abstract no. MoPe14.1B04) suggesting the need of a viral subtype surveillance study to better understand the dynamic of the epidemic. Methods: Blood samples from 163 newly diagnosed HIV-infected individuals were collected at two voluntary testing centers in Buenos Aires, Argentina between March 2003 and October 2005. Subtype characterization was performed by SimPlot analysis on pol and vpu nucleotide sequences and recombination patterns were obtained by bootscanning.Results: BF recombinants were the most prevalent variants (65%), with a higher proportion in women (84.4% compared with 57.6% in men). Subtype B variants were particularly less prevalent in women (6.7 % compared with 37.3% in males). Unusual nonB-nonBF were present in 6.13% (C, BA, BC, BD and CRF06). The proportion of these variants decreased throughout the years (11.1% in 2003, 7.0% in 2004 and 0.0% in 2005, p<0,05 Chi square for trend). Median viral load was higher in those individuals infected with nonB-nonBF variants while B subtype had a tendency to lower values. (Bmedian=44217, BFmedian=74838, nonB-nonBFmedian=272593)Conclusions: Our results show that BF recombinants are still highly prevalent in Argentina and seem to be strongly associated with heterosexual exposure. They also suggest that the introduction of unusual nonB-nonBF variants are decreasing over the years in newly HIV-1 diagnosed individuals in Buenos Aires city.