epi of drug use and hcv in nyc hagan 2005

Epidemiology of drug use and Hepatitis C in New York City (and beyond): 

Epidemiology of drug use and Hepatitis C in New York City (and beyond) Holly Hagan, PhD Director, Research Methods Core Center for Drug Use and HIV Research National Development and Research Institutes New York

What factors affect transmission of an infectious disease in a population?: 

What factors affect transmission of an infectious disease in a population? Environment Virus Host

Factors favoring rapid spread of HCV : 

Factors favoring rapid spread of HCV Host: High proportion of IDUs who share injection equipment Lack of knowledge Fatalism Environment: Large number of infectious carriers capable of transmitting infection to others A lot of infectious material in injection settings Virus: Efficiency of HCV transmission

Risk Factors for HCV: 

Risk Factors for HCV

Injection risk behavior - US IDUs: 

Injection risk behavior - US IDUs

Slide6: 

In a sample of 50 IDUs, 25 are anti-HCV positive Prevalence = 25/50 or 50% = anti-HCV+ = anti-HCV- Prevalence

Slide7: 

80% 80% 33-62% 45% 67% 74% 78% 98% 69% 67% 82% 80% 66% 80% Anti-HCV Prevalence in IDUs around the world 84% 54% 88% 64% 85% 90% 52% 63% 63%

Prevalence of HCV & HIV in IDUs: 

Prevalence of HCV & HIV in IDUs

Anti-HCV prevalence in young or new injectors: 

Anti-HCV prevalence in young or new injectors

Slide10: 

Enrollment 1 year later HCV Incidence 25 anti-HCV negative IDUs followed for 1 year 5 become anti-HCV positive HCV Incidence=5/25, or 20%

Slide11: 

0 12 months 6 months Person Years 1 1 1 1 ½ Person-years: A B C D E Time in the study 4 ½

Incidence of HCV & HIV in IDUs: 

Incidence of HCV & HIV in IDUs

HCV incidence in young or new injectors: 

HCV incidence in young or new injectors

Time to HCV seroconversion in a cohort of Seattle IDUs: 

Time to HCV seroconversion in a cohort of Seattle IDUs Hagan H, Thiede H, & Des Jarlais DC. Epidemiology, 2004.

Time to HCV seroconversion: 

Time to HCV seroconversion Purpose Estimate the length of the opportunity to prevent HCV infection in IDUs 484 HCV-negative Seattle IDUs followed to observe HCV seroconversion Average follow-up 2.1 years Range 0.4 – 7.5 years 1153 person-years of observation 134 HCV seroconversions 11.6/100 person years (all subjects) 15.4/100 person-years (current injectors)

Kaplan-Meier plot of HCV seroconversion in Seattle IDUs: 

Kaplan-Meier plot of HCV seroconversion in Seattle IDUs

Average time to HCV seroconversion from first injection: 

Average time to HCV seroconversion from first injection Used seroincidence and seroprevalence data from 383 new injectors (injecting < 2 years) 41% of new injectors were anti-HCV positive at enrollment Midpoint between 1st injection and enrollment was used to estimate time to HCV infection Anti-HCV negative new injectors were followed up Observed time to HCV infection from 1st injection Used these estimates to calculate a weighted time to seroconversion, using this formula: (41% X time to HCV infection) + (59% X mean time to HCV infection)

Estimated time to HCV seroconversion in new injectors: 

Estimated time to HCV seroconversion in new injectors HCV-positive new injectors: Midpoint between 1st injection and study enrollment 0.6 years HCV-negative new injectors Mean time to HCV seroconversion was 5.4 years Weighted average time to HCV seroconversion (41% X 0.6 yrs) + (59% X 5.4 yrs) = 3.4 years

Odds ratios & relative risks(OR, RR): 

Odds ratios & relative risks (OR, RR) Evaluates risk of disease related to Risk factor Participation in a prevention program Example: Studies of HCV incidence in IDUs

Methadone and HCV prevention : 

Methadone and HCV prevention

Needle exchange & HCV prevention: 

Needle exchange & HCV prevention

Disinfectant bleach & HCV: 

Disinfectant bleach & HCV

Risk Factors Study,New York City 1984-present: 

Risk Factors Study, New York City 1984-present Subjects recruited from drug detoxification program at Beth Israel Medical Center City-wide program, approximately 7000 patients per year Approximately 300 subjects recruited into the study each year, 1990 to 2001 Structured interview, HIV, and (limited) HCV testing DC Des Jarlais, PI Funded by NIDA, CDC, WHO

HIV Prevalence NYC IDUS, 1990-2001: 

HIV Prevalence NYC IDUS, 1990-2001 Source: DC Des Jarlais et al

Recent HIV Incidence StudiesNew York City IDUs : 

Recent HIV Incidence Studies New York City IDUs 13 separate studies Range from 0 to 3/100 person-years Weighted average > 1/100 person years

HCV SeroprevalenceNYC IDUs: 

HCV Seroprevalence NYC IDUs Source: DC Des Jarlais et al

HIV Seroprevalence NYC IDUs, 2002: 

HIV Seroprevalence NYC IDUs, 2002 Source: DC Des Jarlais et al

HCV Seroprevalence NYC IDUs 2000-01: 

HCV Seroprevalence NYC IDUs 2000-01 Source: DC Des Jarlais et al

Recent HCV Incidence StudiesNew York City IDUs : 

Recent HCV Incidence Studies New York City IDUs 3 studies C. Harlem, Lower East Side, E. Harlem Incidence from 10 to 33/100 person years

HCV Seroprevalence in New Injectors, New York City: 

HCV Seroprevalence in New Injectors, New York City Source: DC Des Jarlais et al

Trends in Hepatitis C PrevalenceIn Seattle IDU1994-2003: 

Trends in Hepatitis C Prevalence In Seattle IDU 1994-2003 Burt R, Thiede H, Garfein R, Sabin K,& Hagan H. Manuscript under review, 2005

Seattle Studies of IDUs 18 - 30 years old1994 - 2003: 

Seattle Studies of IDUs 18 - 30 years old 1994 - 2003 RAVEN I 1994 - 1997 Methadone treatment centers, SOS, ADATSA, de-tox, Jail RAVEN II 1998 - 2000 Similar to RAVEN I Kiwi 1998 - 2002 City jail DUIT 2002 - 2003 Street outreach and respondent driven sampling

Limitations : 

Limitations Every study has limitations (bias) that can affect the results Prevalence and incidence can vary greatly in relation to where and how the sample is selected May be very difficult to show that prevention works Community-level effects are difficult to study Prevention programs like needle exchange tend to target high risk injectors

Summary: 

Summary HCV easily transmitted and difficult to prevent! Can’t apply what we know about HIV prevention to HCV and expect the same results However, variation in prevalence and incidence indicates that there are cases where HCV spreads more slowly Prevalence between 30 - 90% Time to HCV seroconversion 1.5 - 3.5 years This is logical, because not all IDUs are alike and not all injection settings are alike We need to study this variation, to understand how we can alter behavior, beliefs and settings to reduce HCV transmission

Acknowledgements: 

Acknowledgements Don Des Jarlais, Hanne Thiede, and Richard Burt provided data from their studies and contributed to many of the ideas in this presentation Support for studies by NIDA, CDC, AmFAR