- Nosocomial Fever of Unknown Origin
- Immune-Deficient Fever of Unknown Origin
- Opportunistic Infection
- Aspergillosis
- Candidiasis
- Herpes Simplex Virus
- HIV-Associated Fever of Unknown Origin
- Cytomegalovirus
- Mycobacterium avium-intracellulare complex
- Pneuomocystis carinii Pneumonia
- Drug-Induced Fever
- Kaposi's Sarcoma
- Lymphoma