AIDS. The disease is quite young but it has already ruined the lives of millions of people. AIDS is considered a slow infectious disease because it may take more than 15 years from the initial infection to the biological death. The disease is characterized by four stages:
• The first stage is characterized by an acute infection and manifests itself as a common viral infection with such symptoms as fever, cough, skin rash, etc.
• The second stage is asymptomatic and there are no signs of the disease at all
• The third stage occurs after 3-5 years and is accompanied by a significantly reduced immunity
• The fourth stage ends up with the complete destruction of the immune system.
According to statistics, about 50 million people suffer from AIDS nowadays and about a half of this quantity doesn’t even suspect about the disease.