A rapid expansion of HIV-1 CRF63_02A1 among newly diagnosed HIV-infected individuals in the Tomsk Region, Russia.

The prevalence of HIV infection in different Russian regions is nonuniform. In the Tomsk region (TR), 2020 HIV new infection cases were recorded in 2013, the morbidity having increased 5.9-fold as compared to 2012. In total, 64 blood plasma samples from primary HIV cases have been examined. HIV-specific fragments of the pol gene have been obtained for 61 samples (of protease for 58 and of integrase for 23) and of the env gene V3 region for 40 samples. Phylogenetic analysis of the determined HIV-1 sequences has detected CRF63_02A1 in 55 (90.2%) cases, whereas HIV subtype A1, characteristic of Russia, has been observed in only three (4.9%) patients. Three (4.9%) cases contain CRF63_02A1/A recombinant variants. This article demonstrates that a drastic activation of the epidemic in the Tomsk region is accompanied by a rapid spreading of the recently described HIV-1 CRF63_02A1, which we detected in the Novosibirsk region outbreak of 2008.

HIV-1 genetic diversity in Russia: CRF63_02A1, a new HIV type 1 genetic variant spreading in Siberia.

One of the factors determining a high degree of heterogeneity in the HIV population is recombination-based variation, which leads to the emergence of the virus variants with a mosaic genome. An example is CRF63_02A1, an HIV-1 variant currently spreading in the Siberian region of Russia. To prove that this HIV-1 variant is a new circulating recombinant form that had emerged as a result of repeated recombination between CRF02_AG and subtype A, we have isolated seven full-length HIV genomes and theoretically analyzed them, that is, reconstructed the phylogenetic relationships, determined recombination breakpoints and regions, and compared them with the regions known for CRF02_AG.