[Are the HIV viruses really the causal agents of AIDS?]

Since the discovery and characterization of the Human Immunodeficiency Viruses (HIV) it seems to be firmly established that these infectious agents are the cause of AIDS. Since a few years ago, however, we and other investigators have noted a number of unexplained facts that cast many doubts over the simplistic hypothesis of a unique retroviral etiology of AIDS. It is likely that many other factors act synergistically to induce immunosuppression in these patients i.e.: a) repeated and chronic infections; b) use of drugs; c) alloantigenic stimulation by blood and/or semen; d) anesthetics; e) antibiotics and f) malnourishment. The role of these etiologic cofactors is critically analyzed in view of recent and old literature. Other alternative hypothesis for the etiology of AIDS, such as those proposed by Root-Bernstein and Duesberg are discussed.