MOLECULAR EPIDEMIOLOGY OF AN HIV-1 SUBTYPE-A SUBCLUSTER AMONG INJECTION-DRUG USERS IN THE SOUTHERN UKRAINE

Phylogenetic characterization of primary isolates from 17 HIV-l-infect ed individuals within a recent epidemic in the city of Odessa, Ukraine was conducted. The isolates were drawn from two time periods, 1993 an d 1996. The 1996 isolates coincided with the first apparent expansion of HIV-1 among injection drug users (IDU), Multi-locus phylogenetic an alysis indicated that HIV-1 gag, env, tat, and long terminal repeat (L TR) sequences all conformed to the HIV-1 classification of a subcluste r within subtype A, There was no evidence for inter-subtype recombinan ts among these isolates. A number of potential signature sequences, pa rticularly within env, were identified in these two time periods, poss ibly suggesting a selective pressure on viral evolution among IDU, Res ults of this study are consistent with a recent introduction and subse quent independent evolution of an HIV-1 subtype A subcluster among IDU in the Southern Ukraine, This study demonstrates a congruence of mult i-locus phylogenetic analysis, and suggests that non-B genetic subtype s, such as HIV-1 subtype A, may become relevant to the study of IDU tr ansmission in the future.