Incorporating all these suggestions could give this version:

AIDS (Acquired Immunodeficiency Syndrome) is a global human epidemic. The etiologic agent of AIDS is a retrovirus designated human immunodeficiency virus HIV. AIDS is defined as a CD4+ T-lymphocyte count less than 200 cells/uL or an AIDS-defining condition in persons with HIV antibodies. 

This avoids much of the POV unreferenced specualation  01:49, 4 Jun 2005 (UTC)