The high incidence of HIV infection places St Petersburg among the worst IDU-concentrated epidemics in Europe. Interventions targeting psychostimulant and heroin users and their accompanying behaviors such as frequent injections and increased sexual activity are needed immediately.

The purpose of this analysis was to estimate human immunodeficiency virus (HIV) prevalence and testing patterns among injection drug users (IDUs) in St. Petersburg, Russia. HIV prevalence among 387 IDUs in the sample was 50%. Correlates of HIV-positive serostatus included unemployment, recent unsafe injections, and history/current sexually transmitted infection. Seventy-six percent had been HIV tested, but only 22% of those who did not report HIV-positive serostatus had been tested in the past 12 months and received their test result. Correlates of this measure included recent doctor visit and having been in prison or jail among men. Among the 193 HIV-infected participants, 36% were aware of their HIV-positive serostatus. HIV prevalence is high and continuing to increase in this population. Adequate coverage of HIV testing has not been achieved, resulting in poor knowledge of positive serostatus. Efforts are needed to better understand motivating and deterring factors for HIV testing in this setting.

We evaluated the efficacy of a peer-educator network intervention as a strategy to reduce HIV acquisition among injection drug users (IDUs) and their drug and/or sexual networks. A randomized controlled trial was conducted in St. Petersburg, Russia among IDU index participants and their risk network participants. Network units were randomized to the control or experimental intervention. Only the experimental index participants received training sessions to communicate risk reduction techniques to their network members. Analysis includes 76 index and 84 network participants who were HIV uninfected. The main outcome measure was HIV sero-conversion. The incidence rates in the control and experimental groups were 19.57 (95 % CI 10.74–35.65) and 7.76 (95 % CI 3.51–17.19) cases per 100 p/y, respectively. The IRR was 0.41 (95 % CI 0.15–1.08) without a statistically significant difference between the two groups (log rank test statistic X2 = 2.73, permutation p value = 0.16). Retention rate was 67 % with a third of the loss due to incarceration or death. The results show a promising trend that this strategy would be successful in reducing the acquisition of HIV among IDUs.

There are limited data on the genetic complexity of human immunodeficiency virus type 1 (HIV-1) after transmission among a cohort of injection drug users (IDUs). We used single-genome amplification of HIV-1 env to determine the genotypic characteristics of virus among IDUs with acute infection in St Petersburg, Russia. Our results indicate that a single variant was transmitted in a majority of cases (9 of 13 participants), which is analogous to what is observed in sexual transmission. These data are most consistent with a genetic bottleneck during transmission by injection drug use that is due to a small inoculum, which most often results in the transmission of a low-complexity viral population.