Estimates of HIV incidence among drug users in St. Petersburg, Russia: continued growth of a rapidly expanding epidemic
Date
2010-07-30
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Abstract
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.
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Keywords
human immunodeficiency virus, HIV, incidence, injection drug users, Russia