Outbreak of a West African recombinant of HIV-1 in Tashkent, Uzbekistan.

Objectives: This research describes the genetic diversity of HIV-1 in Uzbekistan. Methods: During 2002 and 2003, blood from HIV-positive patients in Uzbekistan was collected, and part of the proviral pol gene and nearly full-length genomes were sequenced and analyzed. Results: Among 142 Uzbek strains, most clustered genetically with the subtype A strain common in the former Soviet Union. Most of these subtype A-infected drug-naive subjects (65.6%) had an accessory drug resistance mutation, A62V, in the reverse transcriptase gene. Thirteen of the strains (9.2%) clustered with CRF02_AG, an HIV strain common in West Africa. People infected with CRF02_AG were all residents of Tashkent and sampled in 2002. The CRF02_AG strains were monophyletic and probably descended from a single ancestor. Two strains were recombinant between CRF02_AG and subtype A, with each having a different subtype structure. The CRF02_AG and the subtype A elements of the recombinants were monophyletic with Uzbek CRF02_AG and subtype A. New full-length genomes of 12 Uzbek strains suggested that neither the subtype A and nor the CRF02_AG strains in this epidemic were mosaics with other subtypes or circulating recombinant forms. Conclusion: A genetic analysis of Uzbek HIV strains demonstrated the predominance of subtype A in the epidemic. An outbreak of a West African strain of HIV-1, CRF02_AG, occurred in Tashkent, Uzbekistan in 2002, however. The cocirculation of the 2 strains has resulted in new recombinants that are apparently unique to Uzbekistan.