Figure 1From: Temporal dynamics of HIV-1 circulating subtypes in distinct exposure categories in southern BrazilPrevalence of HIV-1 subtypes in Porto Alegre in the two studied populations (1998 and 2005–2008) according to exposure categories (A) Heterosexual and (B) Men who have sex with men. Black bars represent Group I and gray bars represent Group II. Symbols represent statistical significance, * = p<0.05; ** = p<0.01.Back to article page