WHO Disease Staging System for HIV Infection and Disease in Adults and Adolescents


WHO Disease Staging System for HIV Infection and Disease in Adults and Adolescents was first produced in 1990 by the World Health Organization and updated in September 2005. It is an approach for use in resource limited settings and is widely used in Africa and Asia and has been a useful research tool in studies of progression to symptomatic HIV disease.
Following infection with HIV, the rate of clinical disease progression varies enormously between individuals. Many factors such as host susceptibility and immune function, health care and co-infections, as well as factors relating to the viral strain may affect the rate of clinical disease progression.

Revised World Health Organization (WHO) Clinical Staging of HIV/AIDS For Adults and Adolescents (2005)

Primary HIV infection

Conditions where a presumptive diagnosis can be made on the basis of clinical signs or simple investigations
Conditions where confirmatory diagnostic testing is necessary
Conditions where a presumptive diagnosis can be made on the basis of clinical signs or simple investigations
Conditions where confirmatory diagnostic testing is necessary

Clinical Stage I

Performance scale: 1: asymptomatic, normal activity.

Clinical Stage II

And/or performance scale 2: symptomatic, normal activity.

Clinical Stage III

And/or performance scale 3: bedridden < 50% of the day during last month.

Clinical Stage IV

The declaration of AIDS
And/or performance scale 4: bedridden > 50% of the day during last month.
HIV wasting syndrome: weight loss of > 10% of body weight, plus either unexplained chronic diarrhoea or chronic weakness and unexplained prolonged fever.
HIV encephalopathy: clinical findings of disabling cognitive and/or motor dysfunction interfering with activities of daily living, progressing over weeks to months, in the absence of a concurrent illness or condition other than HIV infection which could explain the findings.