acquired immune deficiency syndrome (AIDS)

Definition

Most deadly (and so far incurable) infectious disease, caused by human immunodeficiency virus (HIV). The HIV destroys a subgroup of white blood cells (lymphocytes) called 'T cells,' resulting in suppression of the body's immune response. Its progression to chronic stage causes symptoms such as severe diarrhea, extreme fatigue, intermittent fever, night chills and sweats, and weight loss, leading to opportunistic infections (such as meningitis, pneumonia, tuberculosis) and/or tumors.