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The article focuses on the characteristics of active high-risk injection drug users (IDUs) to evaluate the connection between behavioral and demographic characteristics and HIV-1 infection and to describe the recruitment methods in St. Petersburg, Russia. Researchers have analyzed HIV-1 prevalence as a function of sociodemographic and behavioral variables. The researchers have assessed the HIV prevalence of IDUs. Results have indicated that the city is among the worst IDU-concentrated epidemics in Europe. Finally, the connection of sociodemographic and behavioral factors to prevalent HIV infection remain to be elucidated.

Background: Russia has one of the world’s fastest growing HIV epidemics and it has been largely concentrated among injection drug users (IDU). St Petersburg, Russia’s second largest city, is one of the country’s regions that has been most affected by the HIV epidemic. To monitor the current epidemic situation, we sought to estimate recent HIV incidence among IDU in St Petersburg. Methods: In a cross-sectional study of 691 IDU recruited during 2005–08, HIV incidence was estimated by two methods: a retrospective cohort analysis and BED capture enzyme immunoassay (EIA) results. Socio-demographic and behavioural correlates of incident infections and spatial patterns were examined. Results: In the retrospective cohort analysis, the incidence rate was estimated to be 14.1/100 person-years [95% confidence interval (CI) 10.7–17.6]. Using results of BED EIA and two correction formulas for known misclassification, incidence estimates were 23.9 (95% CI 17.8–30.1) and 25.5 (95% CI 18.9–32.0) per 100 person-years. Independent correlates of being recently infected included current unemployment (P = 0.004) and not having injected drugs in the past 30 days (P = 0.03). HIV incident cases were detected in all but one district in the city, with focal areas of transmission observed to be expanding. Conclusions: High HIV incidence among IDU in St Petersburg attests to continued growth of the epidemic. The need for expansion of HIV prevention interventions targeted to vulnerable populations throughout the city is urgent. These results also suggest that the BED EIA may over-estimate incidence even after correction for low specificity. [ABSTRACT FROM AUTHOR]

Background: To date, the great majority of Russian HIV infections have been diagnosed among IDUs and concerns about the potential for a sexual transmission of HIV beyond the IDU population have increased. This study investigated differences in the prevalence of sexual risk behaviors between IDUs and non-IDUs in St. Petersburg, Russia and assessed associations between substance use patterns and sexual risks within and between those two groups. Methods: Cross-sectional survey data and biological test results from 331 IDUs and 65 non-IDUs who have IDU sex partners were analyzed. Multivariate regression was employed to calculate measures of associations. Results: IDUs were less likely than non-IDUs to report multiple sexual partners and unprotected sex with casual partners. The quantity, frequency and intensity of alcohol use did not differ between IDUs and non-IDUs, but non- IDUs were more likely to engage in alcohol use categorized as risky per the alcohol use disorders identification test (AUDIT-C). Risky sexual practices were independently associated with monthly methamphetamine injection among IDUs and with risky alcohol use among non-IDUs. Having sex when high on alcohol or drugs was associated with unprotected sex only among IDUs. Conclusions: Greater prevalence of sexual risk among non-IDUs who have IDU sex partners compared to IDUs suggests the potential for sexual transmission of HIV from the high-prevalence IDU population into the general population. HIV prevention programs among IDUs in St. Petersburg owe special attention to risky alcohol use among non-IDUs who have IDU sex partners and the propensity of IDUs to have sex when high on alcohol or drugs and forgo condoms. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Aims To understand the epidemiology and transmission patterns of hepatitis C virus (HCV), the predominant blood borne-pathogen infecting injection drug users (IDUs), in a part of the former Soviet Union. Design Cross-sectional respondent-driven sample of IDUs. Setting St Petersburg, Russia. Participants A total of 387 IDUs were recruited in late 2005 and throughout 2006. Measurements Participants were surveyed to collect demographic, medical and both general and dyad-specific drug injection and sexual behaviors. A blood sample was collected to detect antibodies to hepatitis C and to amplify viral RNA for molecular analysis. The molecular data, including genotypes, were analyzed spatially and linkage patterns were compared to the social linkages obtained by respondent-driven sampling (RDS) for chains of respondents and among the injection dyads. Findings HCV infection was all but ubiquitous: 94.6% of IDUs were HCV-seropositive. Among the 209 viral sequences amplified, genotype 3a predominated ( n = 119, 56.9%), followed by 1b ( n = 61, 29.2%) and 1a ( n = 25, 11.9%). There was no significant clustering of genotypes spatially. Neither genotypes nor closely related sequences were clustered within RDS chains. Analysis of HCV sequences from dyads failed to find associations of genotype or sequence homology within pairs. Conclusions Genotyping reveals that there have been at least five unique introductions of HCV genotypes into the IDU community in St Petersburg. Analysis of prevalent infections does not appear to correlate with the social networks of IDUs, suggesting that simple approaches to link these networks to prevalent infections, rather than incident transmission, will not prove meaningful. On a more positive note, the majority of IDUs are infected with 3a genotype that is associated with sustained virological response to antiviral therapy. [ABSTRACT FROM AUTHOR]