Trends in Incidence of AIDS Illnesses in Australia From... : JAIDS Journal of Acquired Immune Deficiency Syndromes (original) (raw)

Epidemiology

Trends in Incidence of AIDS Illnesses in Australia From 1983 to 1994: The Australian AIDS Cohort

Dore, Gregory J.*; Hoy, Jennifer F.†; Mallal, Simon A.‡; Li, Yueming*; Mijch, Anne M.†; French, Martyn A.‡; Cooper, David A.*§; Kaldor, John M.*

*National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney; †AIDS Unit, Fairfield Infectious Diseases Hospital, Melbourne; ‡Department of Clinical Immunology, Royal Perth Hospital, Perth; §HIV Medicine Unit, St. Vincent's Hospital, Sydney, Australia

Address correspondence and reprint requests to Gregory J. Dore, National Centre in HIV Epidemiology and Clinical Research, Level 2, 376 Victoria Street, Darlinghurst, New South Wales 2010, Australia.

Manuscript received September 11, 1996; accepted March 18, 1997.

Abstract

Summary

To assess time trends in incidence of AIDS illnesses in Australia, a retrospective cohort of people diagnosed with AIDS from January 1, 1983 to December 31, 1994 in three HIV medicine units in Sydney, Melbourne, and Perth was established. Data on initial and subsequent AIDS illnesses were available for 2580 AIDS cases, or 45% of Australian AIDS notifications over the study period. Males represented 97.2% of the cohort, and HIV exposure category was homosexual contact for 89.9%. Subcohorts were formed by interval of AIDS diagnosis: 1983 through 1987, 1988 through 1990, and 1991 through 1994, with estimation of cumulative risk for each AIDS illness by the Kaplan-Meier method. The cumulative risk declined for_Pneumocystis carinii_ pneumonia (PCP) (p < 0.0001) and for Kaposi's sarcoma (KS) (p< 0.0001); PCP cumulative risk estimates 2 years following AIDS diagnosiswere 70% for people diagnosed with AIDS in 1983 through 1987 and 48% in 1991 through 1994, and KS cumulative risk estimates 2 years following AIDS diagnosis were 44% in 1983 through 1987 and 32% in 1991 through 1994. In contrast, cumulative risk increased from 34% to 40% for cytomegalovirus (CMV) disease (p = 0.005), from 47% to 50% for Mycobacterium avium complex (MAC) (p < 0.0001), and from 26% to 33% for esophageal candidiasis (p < 0.0001). Corresponding to this changing spectrum of AIDS illness has been an increase in severity of immunodeficiency at AIDS, with median CD4 cell count declining from 54 cells/mm3 in 1983 through 1987 to 34/mm3 in 1991 through 1994 (p = 0.002).