Trends in HIV diagnoses in Ontario, 2000­2004

1. Trends in HIV diagnoses in Ontario, 2000­2004 Robert S. Remis, Jane Njihia, Carol Swantee, Maraki Fikre Merid Ontario HIV Epidemiologic Monitoring Unit, Public Health Sciences, University of Toronto; HIV Laboratory, Ontario Ministry of Health; Public Health Agency of Canada 14th Annual Canadian Conference on HIV/AIDS Research Vancouver, BC, May 13, 2005

2. Background • In Ontario, essentially all HIV diagnostic testing is conducted at the HIV Laboratory and regional labs • We use diagnostic test results to monitor the HIV epidemic on an ongoing basis • Since 2000, we observed a substantial increase in the number of new HIV diagnoses Dr. Robert S. Remis Public Health Sciences, University of Toronto

3. Study objectives 1. To characterize trends in new HIV diagnoses in Ontario 2. To determine to what extent observed trends due to testing artefact Dr. Robert S. Remis Public Health Sciences, University of Toronto

4. Methods • Examined first-time HIV-positive and total HIV tests from 1985 to 2004, with particular attention to years 2000 to 2004 • First-time HIV positive: confirmed positive with no previous positive result identified and no evidence of previous positive test in Ontario • Adjusted exposure category using data on risk factors from Laboratory Enhancement Study Dr. Robert S. Remis Public Health Sciences, University of Toronto

5. Methods • Based on the observed pattern, defined the baseline year as 2000 • Compared HIV test results for 2004 to those in earlier years by sex, exposure category and reason for testing Dr. Robert S. Remis Public Health Sciences, University of Toronto

6. Number of HIV diagnoses by sex Ontario, 1985-2004 Dr. Robert S. Remis Public Health Sciences, University of Toronto

7. Number of HIV diagnoses by sex Ontario, 2000-2004 Dr. Robert S. Remis Public Health Sciences, University of Toronto

8. Number of HIV diagnoses by exposure category, Ontario, 2000-2004 Dr. Robert S. Remis Public Health Sciences, University of Toronto

9. Possible explanations • Artefact related to: • Impact of immigration testing in 2002 • Impact of increased prenatal testing • General increase in HIV testing • Real increase related to new HIV infection Dr. Robert S. Remis Public Health Sciences, University of Toronto

10. Impact of HIV diagnoses related to prenatal and immigration HIV testing, 2004 versus 2000 Male Female Total Excess HIV 212 155 368 Excess # Visa 74 43 117 Prenatal 26 26 Total 74 69 143 Excess % Visa 35% 28% 32% Prenatal 17% 7% Total 35% 45% 39% Dr. Robert S. Remis Public Health Sciences, University of Toronto

11. HIV tests versus HIV diagnosesMSM, Ontario 2000-2004 Tests Increase HIV diag Increase 2000 18,987 Referent 446 Referent 2001 20,320 7% 448 0% 2002 24,348 28% 570 28% 2003 25,075 32% 557 25% 2004 27,378 44% 634 42% Dr. Robert S. Remis Public Health Sciences, University of Toronto

12. HIV tests versus HIV diagnoses HIV-endemic, Ontario, 2000-2004 Tests Increase HIV diag Increase 2000 6,789 Referent 180 Referent 2001 7,308 8% 224 24% 2002 9,706 43% 281 56% 2003 10,631 57% 252 40% 2004 11,355 67% 240 33% Dr. Robert S. Remis Public Health Sciences, University of Toronto

13. HIV tests versus HIV diagnoses heterosexual, Ontario, 2000-2004 Tests Increase HIV diag Increase 2000 184,082 Referent 146 Referent 2001 196,517 7% 179 23% 2002 248,143 35% 209 43% 2003 256,537 39% 231 58% 2004 277,153 51% 242 66% Dr. Robert S. Remis Public Health Sciences, University of Toronto

14. Summary of findings • From 2000 to 2004, marked increase in HIV diagnoses, especially in heterosexual (+66%), MSM (+42%) and endemic (+33%) exposure categories • Increases partly related to increases in testing for prenatal and immigration, especially in women and persons from endemic countries • Testing increased in all three exposure categories • Endemic:  testing >>  HIV diagnoses • MSM:  testing  HIV diagnoses • Heterosexual:  testing <<  HIV diagnoses Dr. Robert S. Remis Public Health Sciences, University of Toronto

15. Study limitations • Data on reason for testing indicating visa may be incomplete • Data on HIV diagnoses and testing based on adjustments using weights from LES; subject to uncertainty • Limit data on characteristics of subpopulations who present for HIV testing, who are “new” and who are more frequent testers Dr. Robert S. Remis Public Health Sciences, University of Toronto

16. Conclusions • Among persons from HIV-endemic countries, increase likely related immigration testing policy begun in Jan 2002 • MSM: Testing and diagnoses increased about the same, but not necessarily reassuring • Increased testing frequency should not increase number of diagnoses • If epidemic controlled, new persons testing yields few additional diagnoses (“exhaust the prevalent cases”) Dr. Robert S. Remis Public Health Sciences, University of Toronto

17. Conclusions • Heterosexual: Increased diagnoses >> increased tests suggests substantial continued HIV transmission • Study in Toronto and Ottawa to better understand apparent increase in HIV infection among persons infected heterosexually • HIV epidemic in Ontario still unstable and evolving Dr. Robert S. Remis Public Health Sciences, University of Toronto

18. Acknowledgements • Frank McGee, AIDS Bureau, Ontario Ministry of Health and Long Term Care (MOHLTC) • Carol Major, formerly of HIV Laboratory, MOHLTC • OHTN (1999-2000) and Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada (2000-2006) for funding LES