Absence of viral transmission in injecting drug users in Russia

Abstract

In the past 10 years, the abuse of drugs has became a major public- health issue in the former Soviet Union republics. The estimated number of drug users in Russia is up to 3–4 million, most of whom are injecting drug users aged 14–30 years. This epidemic has caused a striking rise in the number of parenterally transmitted infections. At least 100 000 cases of HIV-1 infection had been identified in Russia by March 2001, more than 90% of which were associated with injected-drug use. Moreover, 70–90% of injecting drug users in Russia are infected with hepatitis C virus (HCV). A similar situation now exists in the Ukraine, Belarus, Moldova, Kazakhstan, and other countries in this area. Much genetic variation exists in HIV-1 and HCV, and the variants diverge greatly from those in western Europe. HIV-1 genetic subtype B variants are widespread among injecting drug users in all western European and North American countries.1Expert Group of the Joint United Nations Programme on HIV/AIDSImplications of HIV variability for transmission: scientific and policy issues.AIDS. 1997; 11: 1-15Crossref PubMed Scopus (178) Google Scholar However, three highly homogeneous HIV-1 variants, one belonging to subtype A, another to subtype B, and the third being a gagA/envB recombinant have been identified in injecting drug users in Russia.2Bobkov A Kazennova E Selimova L et al.A sudden epidemic of HIV type 1 among injecting drug users in the former Soviet Union: identification of subtype A, subtype B, and novel gagA/envB recombinants.AIDS Res Hum Retrovir. 1998; 14: 669-676Crossref PubMed Scopus (110) Google Scholar Unlike western Europe, HIV-1 subtype A variants dominate in Russia, where the estimated proportion of HIV-1 infections caused by genetic subtype A has reached 93%. In addition, the genetic subtype B variants found among injecting drug users in the former Soviet Union had characteristic genetic mutations distinguishing them from the western European variants. The Russian subtype B strains clustered together genetically, and were separate from all other HIV-1 strains in injecting drug users worldwide.3Bobkov AF Lukashov W Goudsmit J Weber JN Silent mutation in the V3 region characteristic of HIV type 1 env subtype B strains from injecting drug users in the former Soviet Union.AIDS Res Hum Retrovir. 2000; 16: 291-294Crossref PubMed Scopus (8) Google Scholar Similarly, HCV genomes are highly diverse. HCV genetic subtypes 3a and la dominate among young injecting drug users in western Europe, whereas subtype 1b is rare in individuals younger than 20 years presumed to have been infected through drug use.4Ross RS Viazov S Renzing-Kohler K Roggendorf M Changes in the epidemiology of hepatitis C infection in Germany: shift in the predominance of hepatitis C subtypes.J Med Virol. 2000; 60: 122-125Crossref PubMed Scopus (89) Google Scholar By contrast, HCV genetic subtypes 1b and 3a are the most prevalent among injecting drug users in Russia. They were seen in 96 (39·5%) of 243 and in 84 (34·6%) of 243 clinical samples derived from the Russian injecting drug users aged 14–30 years, respectively. At the same time subtype 1a was only reported in ten (4·1%) of 243 cases. Finally, up to 13% of injecting drug users in western Europe are infected with the human T-cell leukaemia virus type II,5HTLV European Research Network, 1994–1997. Imperial College of Science, Technology and Medicine, LondonApril 1998Google Scholar whereas this virus is not present at all in this risk group in Russia. These data show that contacts between injecting drug users from western Europe and Russia are still limited. One population of transmitted viruses is characteristic for western Europe and the other for most of the former Soviet republics. Intensity of exchange with contaminated equipment among injecting drug users is, of course, not the main indicator of developing cultural relations between countries. However, based on these results, we may conclude that the relationships between the two parts of Europe are much less pronounced than within the European Union or between the former Soviet Union republics; the cultural iron curtain is still to fall. We thank G P Taylor (Imperial College School of Medicine, St Mary's Hospital, London, UK), L M Selimova and E V Kazennova (D I Ivanovsky Institute of Virology, Moscow, Russia) for helpful discussions.