Why Is There Overwhelming Scientific Consensus That HIV Causes AIDS?
Before HIV infection became widespread in the human population, AIDS-like syndromes occurred extremely rarely, and almost exclusively in individuals with known causes of immune suppression, such as chemotherapy and underlying cancers of certain types. A marked increase in unusual infections and cancers characteristic of severe immune suppression was first recognized in the early 1980s in homosexual men who had been otherwise healthy and had no recognized cause for immune suppression. An infectious cause of AIDS was suggested by geographic clustering of cases, links among cases by sexual contact, mother-to-infant transmission, and transmission by blood transfusion. Isolation of the HIV from patients with AIDS strongly suggested that this virus was the cause of AIDS. Since the early 1980s, HIV and AIDS have been repeatedly linked in time, place and population group; the appearance of HIV in the blood supply has preceded or coincided with the occurrence of AIDS cases in every country and
