An acquired immunodeficiency syndrome that results_in involuntary loss of more than 10% of body weight, plus more than 30 days of either diarrhea, or weakness and fever, has_material_basis_in Human immunodeficiency virus 1 or has_material_basis_in Human immunodeficiency virus 2.

Involuntary weight loss of greater than 10 percent associated with intermittent or constant fever and chronic diarrhea or fatigue for more than 30 days in the absence of a defined cause other than hiv infection. A constant feature is major muscle wasting with scattered myofiber degeneration. A variety of etiologies, which vary among patients, contributes to this syndrome. (From Harrison's Principles of Internal Medicine, 13th ed, p1611).