2. World Health Organization: Staging System for HIV Infection and Disase.

Clinical Stage 1	Clinical Stage 2	Clinical Stage 3	Clinical Stage 4
Acute retroviral infection	Weight loss < 10 % body weight	Weight loss > 10 % body weight	Extrapulmonary Tuberculosis
Asymptomatic	Minor mucocutaneous manifestations	Unexplained chronic diarrhoea >1 month	Candida ‐ oesophagus, trachea or bronchi
Persistent generalised lymphadenopathy	Herpes Zoster, within the last 5 years	Oral candidiasis	Pneumocystis carinii pneumonia
+/‐ performance scale 1 (asymptomatic, normal activity)	Recurrent upper respiratory infections	Vulvo‐vaginal candidiasis, chronic (> 1 month)	Herpes simplex ‐ oral >1 month
	+/‐ performance scale 2 (symptomatic, normal activity)	Oral hairy leukoplakia	Herpes simplex‐ visceral, any duration
		Pulmonary Tuberculosis, within past year	HIV wasting syndrome
		Severe bacterial infections	Kaposi's sarcoma
		+/‐ performance scale 3 (bedridden < 50 % of the day)	Toxoplasmosis of the brain
			Cryptococcosis, extrapulmonary
			HIV encephalopathy
			Non‐Typhoid Salmonella bacteraemia
			Cytomegalovirus infection
			Cryptosporidiosis‐diarrhoea > 1 month
			Progressive multifocal leuko‐encephalopathy
			Lymphoma
			Atypical mycobacteriosis, disseminated
			Any disseminated endemic mycosis
			performance scale 4 (bedridden > 50 % of last month)