Is human immunodeficiency virus (HIV) rather than cytomegalovirus the cause of retinitis and colitis in HIV-infected patients?

In the absence of proof that cytomegalovirus is the cause of colitis and retinitis in human immunodeficiency virus (HIV)-infected patients, it is proposed that HIV plays a direct role in the causation of these diseases. Clinical and epidemiologic evidence is cited to support this hypothesis. A direct role for HIV in the etiology of retinitis and colitis in HIV-infected patients could have important implications for antiviral chemotherapy in these diseases.