1. Trends in the Prevalence of Hepatitis C and Hepatitis B and HIV in Seattle Injection Drug Users, 18 – 30 years old, 1994-2004 Richard Burt, Holly Hagan, Richard Garfein, Keith Sabin, Cindy Weinbaum and Hanne Thiede

2. IDU Component of Hepatitis C, Hepatitis B and HIV Disease Hepatitis C: 8,000 – 10,000 deaths/year among all risk groups. –40% of acute disease reported to CDC in recent IDU –Similar figure in 4 sentinel counties Hepatitis B : 3,000 -5,000 deaths/year, all risk groups –18% reported acute disease in recent IDU HIV: 17,000 deaths/year, all risk groups –19% in IDU, IDU/MSM or persons reporting heterosexual sex with an IDU

3. Four Seattle area IDU Study Populations: RAVEN (1994 – 1997) –5 Methadone treatment centers, ADATSA, SOS, de-tox, Jail on drug charges RAVEN II (1998) –1 Methadone treatment center, Stonewall, De-tox, jailed on drug charges –Either: < 26, (or Hispanic, or Native American, or never/new exchange. user) Kiwi (1998 -2002) –Arrested, any charge; at booking or Jail Health Clinic DUIT (2002 -2004) –15 – 30 years old –Community outreach –Coupon-based peer recruitment

4. Comparisons among the study populations Restricted to participants 18-30, injected last 6 months

5. Hepatitis C Seroprevalence p(trend) <.001

6. Hepatitis C Prevalence Trends within Individual Studies Studyp-value (trend) RAVEN.001 Kiwi.11 DUIT.16

7. Hepatitis C Prevalence Trends After Control for Potential Confounding using logistic regression

8. Hepatitis B Seroprevalence p(trend) <.001

9. Hepatitis B Prevalence Trends within Individual Studies Studyp-value (trend) RAVEN.001 Kiwi.40 DUIT.03

10. Hepatitis B Prevalence Trends After Control for Potential Confounding using logistic regression

11. HIV Seroprevalence p(trend) =.54

12. HIV Prevalence Trends After Control for Potential Confounding using logistic regression

13. Sexual Transmission of HIV in Young Seattle IDU 22 of 45 (49%) HIV positive participants were men reporting recent (last 3 – 12 mo.) sex with another man. –8% of the overall study population reported male-to- male sex. In contrast 9% of hepatitis B positive participants reported recent male-to-male sex

14. Time Trends in Risk Behaviors and Preventive Measures

15. Any injection with a needle previously used by someone else p(trend).75

16. Needle exchange primary source of new needles p(trend) <.001

17. Any sharing of cookers p(trend) <.001 (increase)

18. Any self-reported hepatitis B vaccination RAVEN - p(trend) =.49 Kiwi - p(trend) <.001 DUIT – p(trend) =.46

19. Any use of condoms in vaginal or anal sex, among sexually active RAVEN - p(trend) =.72 Kiwi - p(trend) <.001 DUIT – p(trend) =.22

20. Serosorting Using knowledge of one’s own serostatus and that of one’s partner to influence risk behavior: –Avoid sharing injection equipment with persons of opposite sero-status –Preferentially share equipment with partners of the same sero-status –Have persons of positive serostatus use equipment after those negative

21. Participants’ HCV status vs. that of their last injection equipment sharing partner: 2006 NHBS-IDU1 study

22. Hepatitis C prevalence by age

23. Serosorting by number of years participants’ had been injecting I

24. Serosorting by participants’ age II

25. Intentional Serosorting

26. Overview Hepatitis C virus prevalence in young Seattle IDU declined by half between 1994 and 2004. –Trend can be seen within individual studies. –Trend persists after control for potential confounders. –Additional term for study addresses residual confounding Hepatitis B virus seroprevalence in the same population showed a similar pattern. HIV prevalence remained low and stable.

27. Viral Transmission Modes: Implications for mechanisms of declines Hepatitis C – overwhelming through blood contact –Injection equipment sharing –Injection partner sero-sorting HIV – Both sexual and blood contact –~50% MSM => substantial sexual transmission Consistent with IDU data from Baltimore and San Francisco - Condom use - Both sexual and injection partner serosorting Hepatitis B – Both sexual and blood contact –9% MSM => modest sexual component –Vaccination –Injection equipment sharing –Condom use –Sero-sorting

28. Risk Behavior Trends Can Partially Explain the Declines in Prevalence Documentation of reductions in injection equipment sharing are scant Needle exchange use has increased HBV vaccination levels have risen. Condom use levels have risen but remain modest. Serosorting by HCV status is likely to have occurred

29. Data on trends over time in hepatitis HCV is 10 times more likely than HIV to be transmitting in a hospital needle stick. HCV seroprevalence > 40% for 0-4 months of injection, > 70% for 5-8 months of injection (Baltimore, 1996) More recent declines in –Yearly venue-based interviews with San Francisco IDU –Drug treatment admissions to Beth Israel Hospital in New York –Amsterdam open cohort of drug users –Australian needle exchange users –Melbourne Australia methadone center –Scotland HIV testers