Classification of HIV infection and disease in women from Rwanda. Evaluation of the World Health Organization HIV staging system and recommended modifications

Objective: To develop a human immunodeficiency virus (HIV) staging system for sub-Saharan Africa on the basis of an evaluation of the World Health Organization (WHO) system and predictors of mortality. Design: Prospective cohort study with 4 years of follow-up. Setting: Kigali, Rwanda. Patients: 412 HIV-infected women recruited from prenatal and pediatric clinics. Measurements: Clinical signs and symptoms of HIV disease, laboratory assays (including complete blood count and erythrocyte sedimentation rate), and cumulative mortality. Results: The WHO staging system includes a clinical and a laboratory axis. The clinical axis was revised by inclusion of oral candidiasis, chronic oral or genital ulcers, and pulmonary tuberculosis as 'severe' disease (clinical stage IV); in addition, body mass index was substituted for weight loss in the definition for the wasting syndrome. The 36-month cumulative mortality was 7% for women in modified clinical stage I ('asymptomatic'), 15% for those in stage II, 19% for those in stage III, and 36% for those in stage IV (P < 0.001). The laboratory axis was revised by replacing lymphocyte count with hematocrit and erythrocyte sedimentation rate. The 36-month mortality was 10% for women in modified stage A ('normal' laboratory results) and 33% for those in stage B (erythrocyte sedimentation rate >65 mm/h or hematocrit <0.38) (P < 0.001). A single staging system combining clinical and laboratory criteria is proposed, with a 36-month mortality of 7% for women in combined stage I, 10% for those in stage II, 29% for those in stage III, and 62% for those in stage IV (P < 0.001). Conclusions: On the basis of this analysis, a staging system relevant for sub-Saharan Africa is proposed that reflects the range of HIV-related outcomes, has strong prognostic significance, includes inexpensive and available laboratory tests, and can be used by both clinicians and researchers.