World Health Organization clinical case definition for AIDS in Africa: an analysis of evaluations

Abstract

In 1985 at a World Health Organization (WHO) workshop on AIDS in Bangui, Central African Republic, a clinical case definition of Acquired Immune Deficiency Syndrome (AIDS) was developed for developing countries, such as sub-Saharan Africa, where sophisticated diagnostic equipment is not widely available. A particular cachectic syndrome, the "slim disease", which is highly suggestive of AIDS in Africa, constitutes the substratum for the clinical definition for AIDS. The WHO/Bangui definition in adults has a sensitivity of 60%, a specificity of 90%, and a high predictive value especially in endemic areas. The WHO/Bangui clinical case definition for paediatric AIDS is less easy to use in practice. Its low sensitivity (about 35%) is in relation to its incapacity to diagnose many of the frequently observed secondary infection for paediatric AIDS according to the CDC criteria. The WHO/Bangui clinical definition for AIDS seems to be convenient for epidemiological surveillance of the HIV epidemic in Africa. Nevertheless, the low sensitivity and the low specificity result in the failure to detect some cases of full blown AIDS.

PIP: In 1985, at a WHO workshop on AIDS in Bangui, Central African Republic, a clinical case definition of AIDS was developed for developing countries. This 1st definition contained 4 major criteria (chronic asthenia, major weight loss, chronic fever, and chronic diarrhea) and 6 minor criteria (chronic cough, persistent lymphadenopathy, herpes zoster, recurrent herpetic infection, pruritic dermatitis, and oropharyngeal candidiasis). Kaposi's sarcoma and cryptococcal meningitis were sufficient by themselves for the diagnosis of AIDS. In children, the temporary definition of AIDS consisted of 3 major clinical criteria (weight loss and/or abnormally slow growth, chronic diarrhea lasting more than 1 month, and fever lasting more than 1 month), and 6 secondary clinical criteria (generalized lymphadenopathy, oropharyngeal candidiasis, repeated common infections such as otitis and pharyngitis, persistent cough, generalized pruritic dermatitis, and confirmed maternal HIV infection). The revised Bangui definition was evaluated in 174 adult patients hospitalized at the Mama Yemo Hospital of Kinshasa, Zaire. 46% of 174 patients met the criteria of the WHO/Bangui definition. Overall, the sensitivity of the definition for HIV-1 infection was 59%, the specificity was 90%, and the positive predictive value (PPV) was 74%. However, the clinical case definition of African AIDS lacks specificity when it is applied to patients suffering from cachectic syndromes. The Bangui definition was also evaluated at the pediatric ward of Mama Yemo Hospital with 159 hospitalized children whose mean age was 33 months. 21 (13%) were infected by HIV-1. The sensitivity of the definition was 35%, its specificity was 86%, and its PPV was 26%. Although the specificity was relatively high, the low values of sensitivity and PPV underline the weakness of the Bangui clinical case definition for diagnosing pediatric AIDS cases.