In AIDS patients, Kaposi’s sarcoma is considered an opportunistic infection, i.e., a disease that is able to gain a foothold in the body because the immune system has been weakened. With the rise of AIDS in Africa, where KSHV is widespread, Kaposi’s sarcoma has become the most frequently reported cancer in some countries, such as Zimbabwe.
Because of their highly visible nature, external lesions are sometimes the presenting symptom of AIDS. Kaposi’s sarcoma entered the awareness of the general public with the release of the film Philadelphia, in which the main character was fired after his employers found out he was HIV-positive due to visible lesions. Unfortunately, by the time Kaposi’s sarcoma lesions appear, it is likely that the immune system has already been severely weakened.
In AIDS victims, Kaposi’s sarcoma is unique insofar as it is far more prevalent in gay men than in the non-gay male AIDS population. Why the cancer would opportunistically infect gay men is unknown. There is evidence that KSHV is secreted in saliva, and it is possible that use of salive as a lubricant may contribute to its spread in this population. Dr. Dean Hamer of the National Institutes of Health has offered that the cancer may have a genetic underpinning somehow related to a gay gene and his reasearch on the topic in the early 1990s and postulation of such a gene caused a political firestorn as described in Biology and sexual orientation.