MOLECULAR TRACING OF HETEROSEXUAL HIV-1 TRANSMISSION IN GEORGIA.

HIV epidemic in Georgia has entered a new phase with number of heterosexually acquired infections rising each year. Epidemiological data indicates that this switch in epidemic trends is largely due to HIV positive male IDUs transmitting the virus to their female sexual partners. However, no genetic studies confirming linkage between IDUs and their sex partners were done in Georgia before. The objective of our study was to investigate molecular epidemiology of HIV-1 transmission events between heterosexual couples. Viral genotypes were obtained from plasma specimens of 36 heterosexual HIV-1 positive antiretroviral treatment (ART) naive persons representing 18 epidemiologically linked transmission events were genotyped and phylogenetic analyses were done on HIV pol sequences. HIV infection among all women was attributed to heterosexual transmission from their partners. None of 18 women had history of IDU. Fourteen pairs had subtype A virus, three - subtype B and one - subtype G viruses. Phylogenetic analysis confirmed the existing epidemiological link in 16 pairs with bootstrap values ranging from 88% to 100%. Of these 16 events, viruses from 14 pairs had genetic distance less than 0.015.Mutation A62V was seen in samples from 5 pairs, of them samples from 4 pairs additionally had V77I mutation. All 5 pairs were infected with the subtype Avirus. Women, who are sexual partners of IDUs or other men with high risk heterosexual behaviors, are at increased risk of HIV acquisition. HIV epidemic in Georgia has not spread to general population and remains concentrated around key populations at risk. Our work confirms that female sexual partners can serve as a bridge between key affected populations and general community, such as heterosexually active adults. Therefore, prevention efforts targeting key populations at risk and their sexual partners need to be expanded to avoid the spread of the infection within specific communities and beyond.