Nosik M.N.¹, Ryzhov A.K.¹, Kravtchenko A.V.², Kuzin S.N.¹, Tlenkopachev R.S.³,

Hewlett I.K.⁴, Zverev V.V¹., Pokrovsky V.V.²

1- I.I. Mechnikov Research Institute for Vaccines and Sera, Moscow,Russia
2- Central Research Institute of Epidemiology Ministry of Health, Moscow, Russia

3 - Nalchik Republican Blood Transfusion Center, Nalchik, Russia

4- Center for Biologics Evaluation and Research, Food and Drug Administration,USA

Epidemiological Monitoring of HIV-infection in the Territory of Russia.

HIV-infection up to present time is one of the most serious global problems. Million of people all over the world is HIV infected. A new case of HIV-infection occurs every minute. Unfortunately in Russia this problem is also exists. At the beginning of 2012 there were 650.231 officially registered HIV-infection cases, of which 55.000 were children. The fact that 68% of all new cases of HIV-infection are accounted for people of age under 30 raises a serious concern. Thus it is evident that the constant epidemiological monitoring of HIV-infection is necessary. Since 1996 up to the present time the intravenous drug use was the dominant route of HIV-transmission (96%) in the most territory of Russia. However in other countries the heterosexual route of HIV-transmission plays the equally significant role as infection via drug injection. The objective of this work was to study the dominant route of transmission of HIV-infection along side with the determination of subtypes dominating in different regions of the country and to see if the epidemiological situation was changing. We focused our study on the two big regions of Russia which differ in their geography and in their industrial development – the Central Region and Caucasian Region (the Kabardino-Balkarskya Republic, in particular).

Over the period of 2009-2011 blood samples (n=117) were collected from drug-naïve HIV-infected individuals senior 18 years and with their informed consent. The individuals were representing different groups of population and were living in the Central Region of Russia (n=67) and in North Caucasian Region (n=50). All individuals were registered in the Federal AIDS Centers. For the confirmation of HIV diagnosis the plasma was examined by EIA –assay kits, in immunoblot and by PCR –assay-kits. For the analysis of genetic diversity HIV primers specifically suitable for studying the HIV-variants circulating in the territory of Russia were calculated and designed. HIV Drug Resistance Database was used for the analysis of HIV-subtypes.

Among the individuals living in the Central Region there were 48 men (71, 6%) and 19 women (28,4%). The age group was 20-25 years both among the men and among the women (95,5%). Only 3 individuals were 38, 43 and 46 years old against 63% of the HIV-positive individuals of the same age in previous years. The percent of the individuals infected via sexual route and via intravenous drug injection was almost equal: 50,7% and 49,3%, respectively (Fig.1). Herewith there were 34,3% heterosexual contacts and 16, 4% men having sex with men (MSM). Among injecting drug users (IDUs) there were 21,2% women and 78,8% men. Two women were living with HIV positive husbands and one woman was IDU living with husband who also practiced intravenous drug injection. As to HIV subtypes A subtype (IDU-A variant) characteristic for the most part of Russia and the territory of former Soviet Republics predominated (82,5%) (Fig.2). This subtype was predominant both among injecting drug users (24,6%) and heterosexually infected individuals (54,4%). Subtype B was prevalent among homosexual men (100%). Sequence analysis of pol gene showed that IDU-A variant was highly homogeneous.

The analysis of HIV-infection among individuals living in the territory of the Kabardino-Balkarskya Republic revealed that here also as in the territory of Central Region the men were dominant among HIV-infected persons (78%). The age group of 24-30 years was most prevalent among men and the age group 24-29 years was prevalent among women- 56% and 36%, correspondingly. According to the questionnaire intravenous drug use was the dominant mode of HIV-infection transmission both among men (74%) and among women (54%) (Fig.1). The percentage of persons who had difficulty in indicating the way they were infected (or who refused to say so) was 2%. The subtypes circulating in the territory of North Caucasian Region (the Kabardino-Balkarskya Republic) were A subtype (73%) and B subtype (27%) (Fig.2).

Thus the analysis of 117 samples obtained from HIV-infected persons living in the territory of Russian Federation (RF) over the period of 2009-2011 showed that in the most part of Russia the highly homogeneous HIV-1 subtype A was still dominating. In North-Caucasian Region (Republic of Kabardino-Balkaria) the dominant way of HIV- infection transmission was intravenous drug infusion. That is well agreed with the prevalence of subtype A which is characteristic for that risk group^{11, 31, 32}.

At the same time relatively high percent of subtype  (27%) in the territory of North-Caucasian Region (the Kabardino-Balkarskya Republic) indicates that there is a rather vast social stratum of HIV-infected men who have sex with men^{31, 33-35} (it must be noted that in Russia subtype B was never detected among IUDs).

The analysis of the epidemiological situation in the territory of Kabardino-Balkarskya Republic as it was expected showed that men were dominant among HIV-infected individuals (78%). The dominant route of spread of infection in this territory was intravenous drug injection. The most likely explanation is that the more homogenous ethnic population and more traditional way of life are characteristic for this region, where men play a more active social role in comparison with women.

As to the Central Region the situation is rather different. A more liberal lifestyle of young people in the cities in comparison with the traditional lifestyle in North-Caucasian Republic could explain the fact that the rate of HIV transmission among women is equal both via intravenous drug injection and via sexual intercourse. The data show that during last years the situation is changing. The virus characteristic mostly for the IDUs is now spreading outside of this cohort and begins to spread via sexual route. Also the age of HIV- positive people became much younger. And that is a very alarming signal.

References

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2. Thomson M.M., Vinogradova A., Delgado E. et al. Molecular Epidemiology of HIV-1 in St. Petersburg, Russia: Predominance of Subtype A, Former Soviet Union Variant, and Identification of Intrasubtype Subclusters. J Acquir Immune Defic Syndr 2009; 51:332-339.

3. Bobkov A.F., Kazennova E.V., Selimova L.M. et al. Temporal trends in the HIV-1 epidemic in Russia: predominance of subtype A. J Med Virol 2004;74:191-196.

4. Chohan B, Lang D., Sagar M. et al. Selection for Human Immunodeficiency Virus Type 1 Envelope Glycosylation Variants with Shorter V1-V2 Loop Sequences Occurs during Transmission of Certain Genetic Subtypes and May Impact Viral RNA Levels. J Virol 2005; 79:6528-6531.

5. Spira S., Wainberg M., Loemba Ð. et al. Impact of clade diversity on HIV-1 virulence, antiretroviral drug sensitivity and drug resistance. J Antimicrobiol Chem 2003; 10:1-11.

6. Bobkov A., Cheingsong-Popov R., Garaev M. et al. Identification of an env G subtype and heterogeneity of HIV-1 strains in the Russian Federation and Belarus. AIDS 1994; 8:1649-1655.

Fig.1 ROUTE OF TRANSMISSION OF HIV-INFECTION

Fig.2 DISTRIBUTION OF HIV-1-SUBTYPES