Global epidemiology of sexually transmitted HIV infection and communitylevel prevention strategies

Transcription

1 Global epidemiology of sexually transmitted HIV infection and communitylevel prevention strategies Patrick Sullivan, DVM, PhD Emory University, Atlanta Georgia 1

2 Main messages Most HIV infections globally are attributable to sexual transmission of HIV Although many more people are infected with HIV through heterosexual sex, the prevalence of HIV infection is much higher among men who have sex with men Among men and women, anal sex is much more efficient than vaginal sex at transmitting HIV While overall rates of new HIV infections are stable or falling among heterosexuals, rates among MSM are stable or rising Contemporary thinking about prevention measures is towards comprehensive HIV prevention, maximizing the benefits of treatment of HIV infection For MSM, special considerations are needed in providing comprehensive HIV prevention programs. 2

3 Most HIV infections globally are attributable to sexual transmission of HIV 3

4 Adults and children estimated to be living with HIV 2011 North America 1.4 million [1.1 million 2.0 million] Caribbean [ ] Latin America 1.4 million [1.1 million 1.7 million] Western & Central Europe [ million] Middle East & North Africa [ ] Sub-Saharan Africa 23.5 million [22.1 million 24.8 million] Eastern Europe & Central Asia 1.4 million [1.1 million 1.8 million] East Asia [ million] South & South-East Asia 4.0 million [3.1 million 5.2 million] Oceania [ ] Total: 34.0 million [31.4 million 35.9 million] 4

5 Approximate Distribution of Global Persons Living with HIV, by Acquisition Risk, 2011 Sources: UNAIDS IDU factsheet ( UNAIDS 5 Annual WHO Report HIV 2012 department ( December 2, 2014 epidemiology/2012/gr2012/ _unaids_global_report_2012_en.pdf)

6 Approximate Distribution of Global Persons Living with HIV, by Acquisition Risk, 2011 Sources: UNAIDS IDU factsheet ( UNAIDS 6 Annual WHO Report HIV 2012 department ( December 2, 2014 epidemiology/2012/gr2012/ _unaids_global_report_2012_en.pdf)

7 Approximate Distribution of Global Persons Living with HIV, by Acquisition Risk, 2011 Persons living with HIV infection globally, in millions Sources: UNAIDS IDU factsheet ( UNAIDS 7 Annual WHO Report HIV 2012 department ( December 2, 2014 epidemiology/2012/gr2012/ _unaids_global_report_2012_en.pdf)

8 Percent of World Population Who Are MSM 8 Sources: Randall et al, WHO HIV department Archives Sex Behav 2005 December 2, 2014 Mercer et al, AIDS 2004

9 Prevalence of HIV infection among men who have sex with men versus the general population in countries with available data, most recent year 9

10 Although many more people are infected with HIV through heterosexual sex, the prevalence of HIV infection is much higher among men who have sex with men 10

11 11

12 Global HIV prevalence among MSM, Source: Beyrer, Baral, van Griensven, Goodreau, Chariyalertsak, Wirtz, Brookmeyer, The Lancet, 2012

13 Global HIV prevalence of HIV in MSM compared with regional adult prevalence in 2012 Source: Beyrer et al, AIDS 2013

14 Among men and women, anal sex is much more efficient than vaginal sex at transmitting HIV 14

15 Per Act Risk of HIV Transmission, by Type of Sex Sources: Baggeley et al, Int J of Epidemiology Boily WHO et al, HIV Lancet department Infectious December Dis 2, Vittinghoff et al, Am J Epi 1999

16 Myth: Anal Sex is Uncommon Among Heterosexual Couples United States France: 6% prior year UK: 7% prior year Denmark: 14% prior year Source: Baggeley et al Am J Reproductive Immunol, WHO Aral HIV et department al, J Infect December Dis , 2014 Halperin et al, AIDS Patient Care STDs, 1999

17 Attributable Fraction of New HIV Infections Per Year due to AI and Acute Infections, Model of South African Men and Women Source: Baggeley et al Am J Reproductive Immunol,

18 Modeling Results for MSM in the USA and Peru 18 Source: Beyrer, Baral, van Griensven, Goodreau, Chariyalertsak, Wirtz, Brookmeyer, The Lancet, 2012

19 While overall rates of new HIV infections are stable or falling among heterosexuals, rates among MSM are stable or rising 19

20 People New HIV infections and AIDS-related deaths, New HIV infections AIDS-related deaths Globally new HIV infections peaked in

21 Changes in HIV Incidence,

22 Source: Likatavicius and van de Laar, Eurosurveillance,

23 23

24 From: Estimation of HIV Incidence in the United States JAMA. 2008;300(5): doi: /jama Figure Legend: Tick marks denote beginning and ending of a year. The model specified periods within which the number of HIV infections was assumed to be approximately constant. MSM indicates men who have sex with men; IDU, injection drug use. WHO HIV department Copyright 2012 American Medical Date of download: 8/19/2013 December 2, 2014 Association. All rights reserved. 24

25 Declining HIV Prevalence in Antenatal Clinics, Kenya, Source: Cheluget et al, Sex Trans Infect

26 Decline in HIV prevalence in pregnant women attending for routine check-ups at 19 ANCs, Zimbabwe, Gregson S et al. Int. J. Epidemiol. 2010;39: Published by Oxford University Press on behalf of the International Epidemiological Association The Author 2010; all rights reserved.

27 HIV Incidence Among MSM Globally, 2013 Update Source: Beyrer et al, AIDS

28 What is Driving Declines in Some Heterosexual Epidemics? Behavior change (reduced exposures) Increases in treatment of HIV-positive people (reduced infectiousness) Population-level effects (epidemic dynamics) More recently, circumcision? 28

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30 Contemporary thinking about prevention measures is towards comprehensive HIV prevention, maximizing the benefits of treatment of HIV infection 30

31 Highly Active HIV Prevention Source: Coates et al, Lancet

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33 Behavior Biomedical Barrier Structural Social Societal

34 What are our targets? Important epidemic drivers Different points in the pathway of infection Good primary interventions High risk of anal sex for HIV acquisition High unk HIV prevalence in partner pools High viral load in HIV+ partners Condoms (80%) PrEP (44%) HIV testing (68%) Treatment for HIV+ men (96%?) Changing behaviors (testing, adherence, condom uptake, linkage, retention) Safe places for prevention, culturally competent care, stigma, criminalization

35 For MSM, special considerations are needed in providing comprehensive HIV prevention programs 35

36 Challenges to Preventing HIV in MSM Prejudice, threats and violence against (people thought to be) MSM Lack of training for health care workers Criminalization of same sex behavior Technical challenges to testing prevention packages 36

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38 Baral et al, PLoS ONE (3): 38

39 Legal Status of Homosexuality,

40 Steps to Provide an Enabling Environment to Reduce Sexual Transmission of HIV Among MSM Decriminalization Cultural competency training for health care providers Training of medical students in non-judgmental sexual history taking Human rights approaches to assure access to medical care and treatment 40

41 Summary Sexual transmission remains the primary driver of global HIV epidemics There are more HIV infections through penile-vaginal sex because there are more male-female couples in the world; however, MSM have profound disparities in HIV prevalence in all regions of the world There are important gaps in data in many parts of the world More needs to be done to decrease new HIV infections through all routes; there is special urgency for comprehensive prevention services for MSM in most parts of the world 41

42 Thank you 42