Drug use and high-risk sexual behavior among vulnerable youths, together with concurrent stigma, are fueling an "underground HIV epidemic" in much of the former Soviet Union, says a recent UNICEF report. Eastern Europe and Central Asia are the world's only regions where new HIV infections continue to rise, according to UNAIDS.

"Today, street children in the region are dying of AIDS and drug use in much the same way as they died of cold, famine, and typhoid in the twentieth century," the UNICEF report states.

Last year, Russia reported an 8 percent increase in new HIV diagnoses, though some parts of the federation have seen a 700 percent increase since 2006. HIV prevention program coverage of injecting drug users has declined in Russia and Georgia, UNAIDS said.

"There's an unwillingness to acknowledge that there are young people and minors involved in these behaviors," said Nina Ferencic, report co-author and a regional HIV/AIDS specialist for UNICEF. "We hope to raise attention to the issues affecting children and young people who are either vulnerable, engaging in risky behaviors, or already living with HIV and AIDS."

Homeless and poor youths are especially at risk, given that one-third of new HIV cases in the region are among those ages 15-24. Of the estimated 3.7 million people who inject drugs in the region, one-fourth are believed to have HIV. In addition, many youths end up working in the sex trade.

A recent study suggested that up to 40 percent of homeless minors in St. Petersburg could have HIV. More than half of 319 participants ages 15-19 reported injecting drugs; 96 percent were sexually active; and a quarter had more than six sexual partners a year.

"Children and adolescents living on the margins of society need access to health and social welfare services, not a harsh dose of disapproval," said UNICEF Executive Director Anthony Lake.