Ukraine is experiencing one of the most severe HIV/AIDS epidemics in Europe and the Commonwealth of Independent States (CIS), with an estimated 230,000 people aged 15 and over living with HIV at the end of 2011. In 2011, the HIV prevalence in adults aged 15-49 in Ukraine was estimated at 0.76%. Only slightly more than 124,000 patients with HIV/AIDS were under regular medical observation. Considering the overall estimation of people living with HIV, this suggests that a significant proportion of people with HIV are unaware of their status, and therefore unable to take adequate measures to preserve their health or prevent further transmission. Although the evidence suggests that incidence among people who inject drugs (PWID) is declining, the number of newly reported HIV cases in the country continued to increase annually from 1999 through 2011, largely due to transmission to sex partners and diagnosis of long standing infections as people developed immunosuppression. In 1999, there were 5,827 newly registered HIV cases, in 2010 - 20,489, and in 2011 - 21,177. The majority of reported cases to date have been among PWID and the prevalence of HIV infection is significantly higher among PWID than in any other at-risk population, including female sex workers (FSWs) and men who have sex with men (MSM). The HIV epidemic is, however, evolving. Annually since 2008, more than half of newly registered HIV cases (excluding HIV-exposed infants) have been attributed to heterosexual transmission and the proportion of cases among PWID has progressively decreased. However, there is indirect evidence that the majority of heterosexual cases occur among sexual partners of current or former injection drug users. In 2012, a small decrease in cases to 20,754 was reported, marking the first annual decrease since 1999. The plateauing in reported cases supports that the bulk of individuals infected during the early wave of the epidemic have been diagnosed and current transmission has been partially controlled. The impact of Ukraine's HIV epidemic is exacerbated by a parallel tuberculosis (TB) epidemic. TB is the leading opportunistic infection associated with AIDS morbidity and mortality. According to the Ukraine Harmonized AIDS Response Progress Report (2012), in Ukraine in 2011, TB was diagnosed in 5,745 cases (or 62.5%) of 9,189 new AIDS cases while WHO reports that 19% of the 31,776 TB patients tested for HIV were HIV-positive.