Genetic diversity of HIV-1 at the current stage of the epidemic in the Russian Federation: an increase in the prevalence of recombinant forms

The aim of the study: assessment of genetic diversity and prevalence of recombinant forms of HIV-1 at the current stage of the epidemic in the Russian Federation. Materials and methods . The study used collections of blood and its components obtained from 3178 HIV-infected patients of federal and regional «Centers for the Prevention and Control of AIDS» in the period from 2011 to 2020. Next, the extraction of proviral DNA or HIV-1 viral RNA was carried out, followed by amplification of the pol gene region and sequencing of the ampli fication products. Then, the obtained nucleotide sequences were analyzed to determine their subtype and the prevalence of recombinant forms of the virus was estimated. Results and discussion . It was found that sub-subtype A6 remains the dominant (82.9%) genetic variant of HIV-1 at the current stage of the epidemic in the Russian Federation. The second most common was subtype B — 7.14%. The share of each of the recombinant forms of HIV-1 — CRF02_AG and CRF03_AB accounted for about 1% of all analyzed samples, CRF63_02A6 — about 3.59%. In addition to circulating recombinant forms of HIV-1, 87 unique recombinants (2.74%) were identified. A significant (p<0.001) increase in the frequency of occurrence of HIV-1 recombinant forms of over time was revealed. The largest proportion of recombinant forms of HIV-1 was detected in the Siberian (35.83%) and Northwestern (15.98%) federal districts, the smallest — in the Volga (1.99%) and Ural (2.36%) federal districts. Conclusion. The results obtained indicate the growing genetic diversity of HIV-1 in the Russian Federation, along with the spread of HIV infection beyond vulnerable groups, as well as an increase in the frequency of occurrence of recombinant forms of HIV-1 over time and their involvement in the epidemic process.