Acquired immune deficiency syndrome.

The acquired immune deficiency syndrome (AIDS) has been reported in more than 2800 persons in the United States (70 per cent of whom are homosexually active men). AIDS is manifested by impaired cell-mediated immunity that results in various opportunistic infections (especially pneumonia caused by Pneumocystis carinii) or malignant disease (especially disseminated Kaposi's sarcoma). The cause is unknown, and effective treatment is not yet available. AIDS apparently is not highly infectious for persons outside the acknowledged high-risk groups.