The latest publication* from members of CARE Consortium has investigated the spread of HIV-1 in Southern Russian and characterising the A6 sub-subtype that is clearly distinct from the subtypes circulating in Western Europe and the Americas, but dominant in the Russian Federation.
HIV-1 is a very diverse virus, with numerous genetic subtypes circulating worldwide. Some countries are being disproportionately affected by a specific strain of HIV. The massive HIV epidemic in Russia appears to be continuously dominated by a unique subtype A variant, referred to as A6. Nevertheless, epidemiological data is limited and identification of A6 strain is challenging. So far, A6 variants are interpreted as A or A1 in the commonly used HIV-interpretation systems.
Why is it important to know which strains are present in the area?
Scientists from the University of Cologne together with the CARE partners in Russia (Moscow, Rostov, Krasnodar) have analysed HIV samples obtained from 303 patients to develop a methodology for the systematisation of A6 identification. All patients that were participating in the study attended the Russian Southern Federal Centre for HIV Control (Rostov-na-Donu), Rostov State Medical University Hospital and the Krasnodar Clinical Centre for HIV Control.
The study also described the HIV epidemiology in Southern Russia in order to support the development of an efficient regional framework for HIV-1 infection management.
Understanding of the strains of HIV-1 circulating in certain areas is particularly important for monitoring of HIV drug resistance and drug-resistant mutations that can be transmitted with the virus and have a significant impact on the treatment of the patients. Overall the non-B subtypes of HIV showed differences in disease progression and a closer look at those strains can improve our understanding of HIV resistance.
HIV-1 epidemic in Southern Russia
The retrospective study has enabled the systematisation of A6 identification and confirmed the large prevalence of sub-subtype A6 (69,6%) of HIV-1 in the region, together with a low frequency of subtype B (3,3%). A uniquely high prevalence of subtype G in this study (23,6%) can be retraced to a monoclonal infection episode in 1988-1989 of 250 children in intensive care units.
Additionally, the study detected single class- and multi-resistance to all antiretroviral drug classes available in Russia, threatening the long-term success of antiretroviral therapy programs. The resistance is present in viruses from both treatment-naïve and treatment-experienced patients with specific mutations linked to individual subtypes of HIV. Resistance to protease inhibitors was detected in 9% of treatment-naïve patients in Southern Russia, which appeared higher than in other European countries. Further studies in larger samples would be required to better define whether the prevalence of drug resistance in Russia is currently declining, similarly to Western Europe and the U.S.A.
Overall, this publication shows a substantial difference in HIV epidemics compared to Western Europa and the Americas and supports the need for the long-term surveillance of pretreatment drug resistance of HIV in Russia and Eastern Europe and the advantages of next-generation sequencing for identifying clinically relevant drug resistance mutations.
Find this and other publications affiliated with CARE Consortium here: https://www.careresearch.eu/publications
*HIV-1 Sub-Subtype A6: Settings for Normalised Identification and Molecular Epidemiology in the Southern Federal District, Russia. Schlösser M, Kartashev VV, Mikkola VH, Shemshura A, Saukhat S, Kolpakov D, Suladze A, Tverdokhlebova T, Hutt K, Heger E, Knops E, Böhm M, Di Cristanziano V, Kaiser R, Sönnerborg A, Zazzi M, Bobkova M and Sierra S. Viruses 2020, 12, 475; https://doi.org/10.3390/v12040475