Figure 1

Spatial Distribution of HIV Cases and Injection Drugs within the City of St. Petersburg. Data from 899 participating injection drug users screened at baseline were sorted by district of residence. For each district, the number of participants, the HIV prevalence, and the percentage of injectors who injected only heroin, only amphetamine-type psychostimulants (ATS), or both within the 30 days prior to entering the study are included on the embedded table. The maps display HIV prevalence (A) and type of drug injected (B) with the size of the pie charts proportional to the number of participants who resided in each of the 13 neighborhoods within the city limits of St. Petersburg. For HIV prevalence, the dark part of the pies represents the seropositive cases. For drug injected, the open part of the pies represents heroin only injectors, the dark part represents ATS only injectors, and the striped part represents injectors of both kinds of drug.