Epidemiologic trends in HIV infection among men who have sex with men in Ontario: The situation in 2003 Robert S. Remis, Maraki Fikre Merid Ontario HIV Epidemiologic Monitoring Unit Department of Public Health Sciences University of Toronto Gay Men’s HIV Prevention Summit AIDS Bureau, Ontario Ministry of Health and Long-term Care Toronto, Ontario, March 17-18, 2004

Background MSM seriously affected by HIV epidemic since the beginning (late 1970s) Many developments have influenced trends in the epidemic since then: Education, information and prevention Identification of HIV in 1984 HIV test developed late 1985 Antiretroviral drugs, 1987-95 HAART 1996-

Objectives To examine trends in incidence and prevalence of HIV infection among MSM in Ontario To assess trends in HIV testing To examine recent increasing trends in number of HIV diagnoses and interpret observations

Methods: Data sources HIV diagnostic data Laboratory Enhancement Study Detuned assay Repeat testers Reported AIDS cases HIV-related mortality

Methods: Data analysis HIV model: incidence and prevalence of HIV infection HIV diagnoses AIDS HIV-related mortality Dr. Robert S. Remis Public Health Sciences, University of Toronto

Reported AIDS cases for selected exposure categories, 1981-2002

First-time HIV diagnoses (adjusted) for selected exposure categories,1985-2002

First-time HIV diagnoses among MSM by health region, 1985-2002

First-time HIV diagnoses (adjusted) MSM, by quarter, 2000-03

Number of HIV tests (adjusted) MSM, 1992-2002

HIV incidence among MSM repeat testers, with 95% CLs, 1992-2001 (30,881 PY) Source: Polaris Seroconversion Study

HIV incidence among MSM repeat testers by age group, 1992-99 Source: Polaris Seroconversion Study

HIV incidence from detuned assay MSM by health region, Oct 1999 – Dec 2002 Source: Laboratory Enhancement Study

HIV incidence from detuned assay MSM by region by period, Oct 1999 – Dec 2002 Source: Laboratory Enhancement Study

Modeled HIV incidence among MSM Ontario, 1977–2002 Dr. Robert S. Remis Public Health Sciences, University of Toronto

Modeled HIV prevalence among MSM Ontario, 1977–2002 Dr. Robert S. Remis Public Health Sciences, University of Toronto

Modeled MSM population at risk, HIV prevalence and incidence by health region, Ontario, 2002 Dr. Robert S. Remis Public Health Sciences, University of Toronto

Modeled HIV prevalence and number diagnosed by exposure category, 2002 Dr. Robert S. Remis Public Health Sciences, University of Toronto

Conclusions Gay men in Ontario continue to be severely affected by the HIV epidemic HIV prevalence: 15% (regional variation:10 -20%) HIV incidence (i.e. new infections) not decreasing and likely increasing Trends in risk behaviour elsewhere are consistent with trend in HIV incidence Reasons for persisting high incidence unclear: treatment optimism? safe-sex fatigue?

Conclusions Observed increase in new HIV diagnoses in 2002 of particular concern May be due to: increased HIV testing or increased HIV incidence

Conclusions Likely due, at least in part, to increased HIV incidence since: increase in HIV+ tests > increase in tests proportion identified as seroconverters by linked tests or serologic evidence is stable incidence in repeat testers increasing (data not shown) data from elsewhere and syphilis epidemic evidence for increased risky sexual behaviour

Acknowledgements AIDS Bureau, Ontario Ministry of Health and Long-Term Care Frank McGee, coordinator HIV Laboratory, Central Public Health Laboratory Carol Swantee, diagnostic data Keyi Wu, programming Jane Njihia Laboratory Enhancement Study Chris Archibald, CIDPC, Health Canada Ontario HIV Treatment Network