Understanding HIV/AIDS: The current state of the HIV epidemic in British Columbia Mark Gilbert, MD, MHSc, FRCPC

Transcription

1 Understanding HIV/AIDS: The current state of the HIV epidemic in British Columbia Mark Gilbert, MD, MHSc, FRCPC STOP HIV/AIDS Provincial Expansion Knowledge Kick Off January 31, 2013

2 Learning objectives Historical trends in HIV/AIDS in BC BC picture compared with the rest of Canada Current landscape of HIV in BC Factors that influence the epidemiologic trends

3 HIV Incidence, BC, : 360 ( ) Estimates provided by the Public Health Agency of Canada.

4 HIV Prevalence, BC, : 11,700 (9,400-14,000) Estimates provided by the Public Health Agency of Canada.

5 Comparison: British Columbia and Canada Estimates provided by the Public Health Agency of Canada

6 AIDS Incidence, BC, BCCDC Surveillance Data (AIDS report based on first AIDS-defining illness/opportunistic infection)

7 Interpreting trends in New HIV diagnoses Individuals who have received a new HIV diagnosis Excludes people with a previous positive result (inside/outside BC) Does not represent true incidence Diagnosis can be made years after infection occurs Doesn t include undiagnosed infections Based on data elicited by public health nurse or testing provider from person with a new diagnosis Influenced by changes in testing behaviour

8 New HIV diagnoses, BC, : 248 new diagnoses BCCDC Surveillance Data

9 New HIV diagnoses: Health Authority, BCCDC Surveillance Data

10 New HIV diagnoses: Gender, BC, : Males 217 cases Females 31 cases BCCDC Surveillance Data

11 New HIV diagnoses: Age distribution, 2012 BCCDC Surveillance Data

12 New HIV diagnoses: Caucasian Ethnicity, BCCDC Surveillance Data

13 New HIV diagnoses: Ethnicity, BCCDC Surveillance Data (other/unknown ethnicity excluded)

14 New HIV diagnoses: First Nations People, BCCDC Surveillance Data

15 Stage of Infection at Diagnosis Acute Infection Advanced HIV Primary Care Guidelines for the Management of HIV/AIDS in British Columbia, BCCFE, 2011 (page 13)

16 New HIV diagnoses: Stage of infection at diagnosis, BC, BCCDC Surveillance Data

17 New HIV diagnoses: Inter-test interval by Exposure Group, BC, % other ethnic minorities (M/F) BCCDC Surveillance Data

18 Annual HIV Incidence and Prevalence, BC, 2011 New HIV infections People living with HIV 3% 3% 1% 23% 19% 43% 16% 54% 31% 3% MSM MSM-IDU 3% IDU Heterosexual (non-endemic) Heterosexual (endemic) Other Estimates provided by the Public Health Agency of Canada.

19 New HIV diagnoses: Exposure Group, BC, BCCDC Surveillance Data

20 New HIV diagnoses: Distribution of Exposure Group within Region, BC, BCCDC Surveillance Data

21 New HIV diagnoses: Heterosexual Contact by Gender, BC,

22 New HIV diagnoses: Heterosexual Contact by Risk, BC,

23 What influences these trends?

24 Photos courtesy of Rick Marchand, CBRC

25 What influences these trends? Factors that directly influence whether infection happens: Viral load & HAART Behaviour Unprotected sex Per-act risk of transmission Sharing syringes or other drug using equipment Number of partners, sexual networks HIV prevalence Co-infections Networks HIV Infection Behaviour

26 Gay, bisexual, and other MSM: Inherent biological differences Anal sex has up to 18 times greater risk of transmission than HIV compared to vaginal sex Greater for receptive vs insertive position Many men use both positions More densely connected sexual networks & faster spread compared to heterosexual networks Greater number of partners Concurrent or overlapping relationships (primary and casual partners)

27 Theoretical impact on incidence if assumed heterosexual parameters Beyrer et al. Lancet 2012; 380(9839):

28 Gay, bisexual, and other MSM: Condom Use, BC, 2010 Condom Use with Anal Sex on Casual Dates past 12 months, by birth cohort, BC, Sex Now 2010.

29 Gay, bisexual, and other MSM: Stage of infection at diagnosis & population viral load, BC, Data provided by BC Centre for Excellence in HIV/AIDS.

30 Gay, bisexual, and other MSM: STI Diagnosis trends, BC, BCCDC Surveillance Data and Clinic Data

31 What influences these trends? Factors that operate within relationships or communities: Knowledge Relationships Attitudes, cultural norms Mental Health Substance Use Violence, coercion, power Relationships Discrimination Relationships Networks HIV Infection Behaviour Community

32 Gay, bisexual and other MSM: New HIV diagnoses by Birth Cohort, BC, BCCDC Surveillance Data

33 Gay, bisexual and other MSM: Primary partners with opposite HIV status, BC Having an Opposite Status Primary Partner, by Participant HIV Status, BC, Sex Now

34 Gay, bisexual and other MSM: Awareness of HIV status Nationally, an estimated 20% of HIV positive MSM are unaware of their HIV infection (PHAC 2012) Based on sero-surveys of gay men/msm in BC: Victoria (2007): 4% Vancouver (2008): 13% 62 Victoria M-Track report 2008, ManCount Sizes Up the Gaps Report 2010

35 Gay, bisexual and other MSM: Awareness of HIV status & previous testing, Vancouver 71% had previously tested, most in the past two years 63 Sero-survey of Vancouver MSM: ManCount Sizes Up the Gaps Report 2010

36 Gay, bisexual and other MSM: HIV Test in past year, BC HIV testing in the past year among gay men, by birth cohort, BC. Sex Now 2011

37 Gay, bisexual and other MSM: HIV Test in past year, by region, BC, HIV test in past 12 months by postal code aggregated region, BC, Sex Now 2011.

38 What influences these trends? Factors at a social or structural level: Health system Stigma, homophobia Criminalization of HIV non-disclosure Socioeconomic status Housing Racism Structural Relationships Networks HIV Infection Behaviour Community Policy Social

39 Gay, bisexual and other MSM: Experiences of marginalization by birth cohort, BC, 2011 Lifetime experiences of marginalization by birth cohort, BC, Sex Now, 2011.

40 Gay, bisexual and other MSM: Poor social support by region, BC, Poor Social Support ( few to no others I can count on for support right now ) by postal code aggregated region, BC, Sex Now, 2011

41 Gay, bisexual and other MSM: Disclosure of male sex partners to primary care provider, BC, 2011 Disclosing male sex partners (out) to a primary care provider by postal code aggregated region, BC Sex Now 2011.

42 Take-home messages Overall decrease in HIV incidence in BC, and among IDU Rates of diagnoses among heterosexual and MSM stable Substantial variation by and within regions, groups Surveillance data heavily influenced by testing Influenced by factors at multiple levels - comprehensive approach Structural Relationship s Networks HIV Infection Behaviour Community Social

43 Thanks