1. Epidemiologic Update on the HIV Epidemic in Ontario
The Situation in the Year 2000
Robert S. Remis, MD, MPH, FRCPC
Department of Public Health Sciences University of Toronto

2. Background HIV epidemic in Ontario is unstable and dynamic
Monitoring trends in HIV transmission (incidence) and burden of HIV infection (prevalence) is critical to evaluate effectiveness of primary prevention and project the need for health and support services
Available data is biased and incomplete but triangulation allows obtaining plausible estimates for HIV incidence and prevalence
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

3. Organization of presentation
Describe the databases and the methodologies used
Overview of HIV epidemic in Ontario
Focus on emerging situations
MSM
IDU
Persons from HIV-endemic countries
Mother-infant transmission
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

4. Methods: Data sources
HIV diagnoses: First-time diagnoses at HIV Laboratory adjusted for unknown risk factors and previous HIV testing using data from Laboratory Enhancement Study
AIDS incidence: Cases diagnosed to December 1999 and reported by October 2000;
HIV-related mortality: Deaths to end 1997 adjusted for underascertainment
HIV-infected mothers and infants: Data reported to CPARG and analyzed by period of HIV diagnosis, infection status of infant and mother’s exposure category
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

5. Methods: Data analysis
HIV model
HIV infection: incidence, cumulative incidence and prevalence
HIV diagnosis: incidence, cumulative incidence and prevalence
AIDS: incidence, cumulative incidence and prevalence
HIV-related mortality: incidence and cumulative incidence
Model values adjusted to fit available data on HIV diagnoses, reported AIDS cases and AIDS deaths and results from back-calculations
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

6. Methods: Data analysis
HIV incidence from repeat testers
Results linked within HIV Laboratory database using name, sex, date of birth, previous test history to identify repeat testers
HIV incidence calculated by exposure category, age and health region using method of Kitayaporn
HIV incidence from detuned assay
HIV-positive sera tested using Abbott EIA assay rendered less sensitive to detect recent HIV infection (< 129 days)
HIV incidence = # discordant sera / (# tested x 129/365)
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

7. Number of first-time HIV diagnoses by sex and proportion female, 1985–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

8. First-time HIV-positive diagnoses among males, n=17,878, HIV Laboratory, 1985–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

9. First-time HIV-positive diagnoses among females n=2,464, HIV Laboratory, 1985–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

10. Reported AIDS cases among MSM, Ontario, 1981–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

11. Reported AIDS cases by exposure category, Ontario, 1981–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

12. HIV incidence among MSM repeat testers, with 95% CLs, 1992-99 (28,103 PY)
Source: Polaris Seroconversion Study

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

14. HIV incidence among MSM repeat testers by health region, 1992-99
Source: Polaris Seroconversion Study

15. HIV incidence from detuned assay among MSM by health region, October 1999–June 2000
Source: Laboratory Enhancement Study

16. HIV incidence from detuned assay among MSM by age group, October 1999–June 2000
Source: Laboratory Enhancement Study

17. Modeled HIV incidence among MSM Ontario, 1977–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

18. Modeled HIV prevalence among MSM Ontario, 1977–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

19. Modeled MSM population at risk, HIV prevalence and incidence by health region, Ontario, 1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

20. HIV incidence among IDU repeat testers with 95% CLs, 1992-99 (26,271 PY)
Source: Polaris Seroconversion Study

21. HIV incidence among IDU repeat testers by health region, 1992-99
Source: Polaris Seroconversion Study

22. HIV Incidence from detuned assay among IDU by health region, October 1999–June 2000
Source: Laboratory Enhancement Study

23. Modeled HIV incidence among IDUs Ontario, 1977–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

24. Modeled HIV prevalence among IDUs Ontario, 1977–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

25. Modeled IDU population at risk, HIV prevalence and incidence by health region (aggregated), Ontario, December 1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

26. HIV incidence from detuned assay among MSM-IDU by health region, October 1999–June 2000
Source: Laboratory Enhancement Study

27. Modeled HIV prevalence among MSM-IDU by health region, 1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

28. Modeled HIV incidence among persons from HIV-endemic regions, Ontario, 1977–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

29. Modeled HIV prevalence among persons from HIV-endemic regions, Ontario, 1977–1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

30. Modeled persons born in HIV-endemic countries, HIV prevalence and incidence by health region Ontario, 1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

31. HIV incidence among high risk versus low risk heterosexual repeat testers
Source: Polaris Seroconversion Study

32. Modeled HIV prevalence among heterosexuals by health region and sex, 1999
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

33. Proportion of HIV-infected infants by period of birth and exposure category of mother Ontario, 1984–1999
Source: Dr Susan King, CPARG

34. Number of HIV-positive mothers by antiretroviral prophylaxis and HIV status of infant, Ontario, July 1994-December 1999
Source: Dr Susan King, CPARG

35. HIV testing among pregnant women receiving prenatal care, Ontario, January 1999 to June 2000
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

36. Limitations
Populations at risk (especially MSM, IDU) are not well characterized (e.g. size, regional variations)
Adjustments for HIV diagnoses, AIDS cases and HIV-related mortality subject to uncertainty
Data on HIV incidence is limited and biased (likely overestimates);
However, these have been taken into account in HIV model
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

37. Conclusions HIV epidemic in Ontario is not yet under control
Good news: AIDS incidence and mortality have decreased
However
Overall, HIV prevalence increased by 22% (16,480 to 20,050) and annual incidence by 50% (1,200 to 1,790) since 1996
Increase in incidence among MSM: 80% (540 to 970)
MSM: preventive intervention efforts need to be systematically reviewed, reassessed and reinforced
HIV-endemic: prevention objectives and guidelines need to be developed and programs conceived, funded and implemented
Mother-infant: invest in education of physicians and women
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

38. Conclusions
Limitations in available data limit precision of HIV incidence estimates; good studies are lacking
Cohort studies among MSM and IDU would be invaluable
HIV prevalence studies with correlates of infection
Prevention research: An idea whose time has come?
Dr. Robert S. Remis
Public Health Sciences, University of Toronto

39. Acknowledgements
Frank McGee, Coordinator, AIDS Bureau, Ontario Ministry of Health and Long Term Care (MOHLTC)
Carol Major and Carol Swantee, HIV Laboratory, MOHLTC
Liviana Calzavara, Ann Burchell and Polaris coinvestigators
Elaine P. Whittingham, University of Toronto
Susan King, Hospital for Sick Children
Evelyn Wallace and Lorraine Schiedel, Public Health Branch, MOHLTC
Ontario HIV Treatment Network (OHTN)
Instructional Media Centre, Laboratory Services, MOHLTC