Kaposi's sarcoma herpesvirus

Kaposi's sarcoma-associated herpesvirus is a variety of herpes that causes Kaposi's sarcoma and, as such, is generally only an issue in patients suffering from AIDS or other persons with immune system deficiencies. It's one of only seven viruses that are known to cause cancer in humans. It's generally only transmitted through intimate contact, similar to HIV, although it's much more contagious.
Although Kaposi's sarcoma was first identified in 1872 as a separate disease, it was not until 1994 that it was confirmed that the virus caused the cancer. Although it can infect otherwise healthy individuals, it does not cause symptoms in such patients.
Its distribution in the population is highly dependent on geography, with approximately 40% of people in sub-Saharan Africa being infected compared to about 4% in Northern Europe, southeast Asia, and the Caribbean. 
Kaposi's sarcoma-associated herpesvirus at Wikipedia
Category:Diseases