A SUDDEN EPIDEMIC OF HIV TYPE-1 AMONG INJECTING DRUG-USERS IN THE FORMER SOVIET-UNION - IDENTIFICATION OF SUBTYPE-A, SUBTYPE-B, AND NOVEL GAGA ENVB RECOMBINANTS/

The former Soviet Union republics have experienced an explosive human immunodeficiency virus type 1 (HIV-1) epidemic among injecting drug us ers (IDUs), consisting mainly of subtype A viruses originated from a p oint source (Bobkov et al,: AIDS Res Hum Retroviruses 1997;13:1195-120 1), To determine whether new HIV-1 subtypes have entered the IDU popul ation, 46 samples derived from IDUs in Russia (n = 39) and the Ukraine (n = 7) were genotyped by heteroduplex mobility assay (HMA). It was s hown that 83% of IDU :HIV-1 strains found in both countries belong to genetic subtype A. However, env subtype B was also found in 17% of cas es. The sequence data showed a marked intrasubtype homogeneity of HIV- 1 (the average means of interpatient genetic distance were 1.1 acid 1. 7% [in the gag gene] or 1.8 and 2.3% [in the env gene] for subtype A a nd subtype B, respectively), confirming the hypothesis of a point sour ce of virus for each subtype variant, Moreover, recombinant gagA/envB variants originating from those two strains were also found in two sam ples collected in the Kaliningrad region of Russia. In conclusion, our results suggest that two strains of HIV-1. belonging to different gen etic subtypes, A and B, as well as gagA/envB recombinants between geno mes of the!se strains, are now circulating simultaneously among IDUs i n the former Soviet Union.