Molecular epidemiology of HIV-1 subtypes based on analysis of pol sequences in Slovenia, 1996-2005

Various studies have demonstrated the increasing prevalence of non-B HIV-1 subtypes in Western Europe. In contrast, knowledge about the molecular epidemiology of HIV-1 in Central and Eastern Europe is limited. The objective of present study was to investigate the HIV-1 molecular diversity as well as time trends in HIV-1 subtype distribution in Slovenia. A retrospective molecular epidemiological survey was conducted on a cohort representing 88% (131/149) of all HIV-1 infected patients diagnosed between January 1996 and June 2005. The study revealed that subtype B is a predominant HIV-1 subtype in Slovenia (110/131; 84%), although a relatively high proportion (21/131; 16%) of non-B subtypes was found. Among them, a high proportion of recombinant (10/21; 48%) and different unclassified strains (8/21; 38%) were identified. Non-B subtype viruses were predominant among heterosexuals (19/21; 90%) and subtype B viruses among men who have sex with men (84/110; 76%). Importantly, 86% (18/21) of patients infected with non-B subtypes were of Slovenian nationality. In contrast to Western European countries, a significant increase (P = 0.015) in the proportion of men who have sex with men was observed recently among newly diagnosed HIV-1 infected patients in Slovenia.