WHO classification system for HIV infection

Clinical Stage 1
1. Asymptomatic infection
2. Persistent generalized lymphadenopathy
3. Acute retroviral infection

Clinical Stage 2
4. Unintentional weight loss of more than 10% body weight
5. Minor mucocutaneous manifestations (e.g. dermatitis, prurigo, fungal nail infections, angular cheilitis)
6. Herpes zoster within previous 5 years
7. Recurrent upper respiratory tract infections

Performance Stage 3
In bed more than normal but less than half of normal daytime during the previous month

Clinical Stage 3
8. Unintentional weight loss of more than 10% body weight
9. Chronic diarrhea for longer than 1 month
10. Prolonged fever for longer than 1 month (constant or intermittent)
11. Oral candidiasis
12. Oral hairy leukoplakia
13. Pulmonary tuberculosis within the previous year
14. Severe bacterial infections
15. Vulvovaginal candidiasis

Performance Stage 4
In bed more than half of normal daytime during previous month

Clinical Stage 4
16. HIV wasting syndrome
17. Pneumocystis carinii (juvenii) pneumonia (PCP)
18. Toxoplasmosis of the brain
19. Crytosporidiosis with diarrhea for longer than 1 month
20. Isosporiasis with diarrhea for longer than 1 month
21. Cryptococcosis, extrapulmonary
22. Cytomegalovirus disease of an organ other than liver, spleen or lymph node
23. Herpes simplex virus infection, mucocutaneous
24. Progressive multifocal leukoencephalopathy
25. Any disseminated endemic mycosis (eg histoplasmosis)
26. Candidiasis of the esophagus, trachea, bronchi, or lung
27. Atypical mycobacteriosis, disseminated
28. Non-typhoid Salmonella septicemia
29. Extrapulmonary tuberculosis
30. Lymphoma
31. Kaposi’s sarcoma
32. HIV encephalopathy