Acquired immune deficiency syndrome (AIDS) is a new disease caused almost certainly by a transmissible agent, which is most likely a retrovirus termed HTLV-III. The disease is mainly spread by sexual, especially homosexual contact. Blood-borne transmission is another recognized form of spreading of the disease; it seems, however, that the disease is not readily spread via casual, non-sexual, or other than blood-borne routes. Although the disease is still concentrated in the major metropolitan areas of the United States, it is now increasingly observed in several countries throughout the world. The basic characteristic of the disease is a profound dysregulation of the immune system as proved by a qualitative and quantitative defect of helper T-lymphocytes as well as by B-cell hyperactivity. Clinical manifestations are those of severe and life-threatening opportunistic infections and unusual neoplasms, particularly Kaposi's sarcoma. The mortality is extremely high and may well approach 100%. Therapeutic efforts include the treatment of opportunistic infections and the search for agents which may reconstitute immunologic competence.
