Disease
AIDS
Advanced HIV: CD4 <200 and opportunistic infections
High-yield clue
A CD4 count below 200 cells/uL, or an AIDS-defining opportunistic illness, marks progression from HIV to AIDS.
Overview
The advanced stage of HIV infection defined by severe CD4 T-cell depletion and AIDS-defining conditions, studied for its opportunistic-infection map rather than the virus itself.
Classification
- Acquired immunodeficiency syndrome
- Retrovirus (HIV) end-stage
- Profound CD4 T-cell depletion
- Blood, sexual, and perinatal spread
Lab & identification clues
- CD4 count below 200 cells/uL threshold vocabulary
- HIV viral load concept
- AIDS-defining illness list vocabulary
Associations
- Opportunistic infections: PCP, cryptococcal meningitis, toxoplasmosis, esophageal candidiasis
- Kaposi sarcoma (HHV-8) association
- At-risk exposures: unprotected sex, shared needles, perinatal
- Wasting and constitutional-symptom vocabulary
Commonly confused with
- Acute (primary) HIV syndrome
- Other congenital or acquired immunodeficiencies
Your notes
Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.