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 De partment of National Health and Welfare. Main outcome measures: Age-st andardized rates of initial AIDS manifestations (1987 Centers for Dise ase Control and Prevention case definition), by year of diagnosis amon g adults in Canada. Results: A total of 6641 adult AIDS cases were exa mined. 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 199 1 (P=0.894). Similarly, the rate of Kaposi's sarcoma (KS) stabilized d uring 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 i llnesses increased from 1.48 per 100 000 in 1987 to 3.43 per 100 000 i n 1991 (P=0.001). For these other AIDS index diseases, significant rat e increases were observed for esophageal candidiasis, cytomegalovirus (CMV) diseases, wasting syndrome, toxoplasmosis, and Mycobacterium avi um complex (MAC) disease. Conclusions: Our study shows a leveling and decline in incidence of KS and PCP, respectively, and a concomitant in crease of other diagnoses, especially esophageal candidiasis, CMV, was ting syndrome, toxoplasmosis, and MAC disease in Canada. These finding s highlight the importance of developing specific strategies to preven t emerging AIDS index diseases and serve as a cautionary note to pract icing clinicians, indicating the relative widening of the spectrum of HIV index diseases.