THE CHANGING SPECTRUM OF AIDS INDEX DISEASES IN CANADA

Objective: To describe the changing spectrum of AIDS index diseases in Canada over a 10-year period from 1981 to 1991. Design: A descriptive, population-based study. Setting: Canada. Patients: All cases of AIDS in Canada reported by the Division of HIV/AIDS Epidemiology of the Department of National Health and Welfare. Main outcome measures: Age-standardized rates of initial AIDS manifestations (1987 Centers for Disease Control and Prevention case definition), by year of diagnosis among adults in Canada. Results: A total of 6641 adult AIDS cases were examined. The rate of Pneumocystis carinii pneumonia (PCP) peaked in 1989 with a rate of 3.18 per 100 000, declining to 2.74 per 100 000 in 1991 (P=0.894). Similarly, the rate of Kaposi's sarcoma (KS) stabilized during this interval from 1.06 per 1 00 000 in 1987 to 1.14 per 100000 in 1991 (P=0.189). In contrast, the rates of all other AIDS-defining illnesses increased from 1.48 per 100 000 in 1987 to 3.43 per 100 000 in 1991 (P=0.001). For these other AIDS index diseases, significant rate increases were observed for esophageal candidiasis, cytomegalovirus (CMV) diseases, wasting syndrome, toxoplasmosis, and Mycobacterium avium complex (MAC) disease. Conclusions: Our study shows a leveling and decline in incidence of KS and PCP, respectively, and a concomitant increase of other diagnoses, especially esophageal candidiasis, CMV, wasting syndrome, toxoplasmosis, and MAC disease in Canada. These findings highlight the importance of developing specific strategies to prevent emerging AIDS index diseases and serve as a cautionary note to practicing clinicians, indicating the relative widening of the spectrum of HIV index diseases.