Russia’s fourth-largest city has an HIV epidemic, according to health officials from that country. Specifically, about 1.5 million residents live in the central city of Yekaterinburg, and nearly 27,000 of them (or 1.8 percent) are estimated to be HIV positive, The Associated Press reports.

HIV awareness is low in the country, and testing is infrequent, said health experts. They estimate that as many as 1.5 million people in Russia are living with HIV, although only 800,000 are registered as having the virus (100,000 cases were reported last year).

At the current rate, the number of new infections will double every five years. In most cases in Russia, HIV is spread through injection drug use, but heterosexual sex is becoming a more common mode of transmission, accounting for slightly over 40 percent of new cases.

Most of the country’s HIV is found in large manufacturing cities in southern Siberia and along drug trafficking routes, reports AP.