Something nasty is in the air in China, and it isn't the infamous smog. Sweeping the country is a new paranoia, in which men become convinced that they've contracted HIV, often blaming their infection on a visit to a prostitute. Hundreds of Chinese men have reportedly been visiting doctors and have refused to believe the evidence of negative HIV tests. So strong is their fear that some men wear masks or refuse to interact with their families for fear of transmitting the disease. Although the men say they feel sick, doctors don't believe they're dealing with a hitherto unknown virus, explains the BBC: