Russia's prime minister last week added HIV/AIDS to a list of diseases that pose a national threat to the country, a move that could be used as grounds for revoking foreigners' work and residency permits, The Moscow Times reports. The list includes HIV, chlamydia, syphilis, leprosy, and tuberculosis. The nation's health ministry now must decide whether foreigners should be tested regularly or just when renewing work or residency permits. It's also not clear whether visitors to the country will be screened for the diseases or denied admission if they test positive for one of the conditions. According to government figures, Russia has very high rates of sexually transmitted diseases, with the latest figures for syphilis showing that prevalence of the disease is about 100 times higher than that of other European countries.