The problem of HIV infection is one of the most important issues in health care of Russia. The HIV prevalence amounted to 728.2 per 100 thousand people in Russia on 31.12.2019. HIV has spread beyond vulnerable populations and is spreading widely in the general population. 62.7% of people got infected in heterosexual contacts in 2019. The proportion of HIV-infected people who injected drugs (PWID) is 33.6%. 2.5% of patients got infected through homosexual intercourses. Objective: To assess the prevalence of HIV among three key populations of the Voronezh region (PWID, sex workers (SW), men who have sex with men (MSM)). To assess the behavioral risks that contribute to infection. Methods: Simultaneous HIV serological studies with interviews on a standard questionnaire with respondent-driven sampling. In 2019 each key group included 100 people. And in previous years the sample for the SW groups was 50-100 people, PWID - 200-300 people.
