Acquired immunodeficiency syndrome--a review and update. History, characteristics of human immunodeficiency virus infection, its replication, biologic factors, and pathogenicity.

The search to find a cure for acquired immunodeficiency syndrome has led to an unprecedented explosion of knowledge about viruses in general, especially retroviruses, of which the human immunodeficiency viruses (HIV) types 1 and 2 are members. We attempt to describe how retroviruses work, particularly HIV-1, and what regulates their expression in the host-cell system. Viral stability and its implications for health care workers is also discussed. One of the many mysteries of HIV is the ability it has to elude normal immune responses. Even though B- and T-cell responses are mounted by people infected with HIV, such responses are restricted and increasingly ineffective as the disease progresses. Host susceptibility plays a major role in the virus' ability to infect individuals. Finally, some current treatment options and the key role of the family physician in the battle against acquired immunodeficiency syndrome are discussed.