Epidemiology of drug use and Hepatitis C in New York City

(and beyond)

Holly Hagan, PhDDirector, Research Methods Core

Center for Drug Use and HIV ResearchNational Development and Research Institutes

New York

What factors affect transmission of an infectious disease in a

population?

Environment Virus

Host

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

Author, Year Sample, design Risk Factor

Multiple studies, 1992- Cross-sectional Time at riskSyringe sharingCooker/cotton sharingBackloadingYoung, new injector

Hagan et al, 2001 317 Seattle IDUs, Cohort

Cooker/cotton sharingSyringe sharing

Hahn et al, 2002 195 San Francisco IDUs, Cohort

Syringe sharing

Thorpe et al, 2002(CIDUS II)

510 IDUs in 6 US cities, Cohort

Cooker/cotton sharing

Injection risk behavior - US IDUs

Location YearSyring

e sharin

g

Cooker/cotton sharing Backloadin

g

New York City

1990-93

1994-95

1996-97

40-50%30-39%20-29%

60-80%

}40-50%

60-80%

}40-50%

San Francisco

1986198819901996

26%14%6%17% 44% 27%

Seattle 1994-96

1997-98

1999-00

38%29%20%

} 70% } 60%

Chicago 1997-99

50% 70%

CIDUS III 1999-04

55% 54%* 26%*

In a sample of 50 IDUs, 25 are anti-HCV positive

Prevalence = 25/50 or 50%

= anti-HCV+

= anti-HCV-

Prevalence

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

Location

Year

HCV Prevalence

HIV Prevalence

Amsterdam 1991 66% 33%

Geneva 1992 80% 32%

Baltimore 1994 90% 25%

Seattle 1999 82% 2%

Rural UK 2000 56% 14%

S. China 2003 72% 17%

Vancouver 2004 44% 19%

Anti-HCV prevalence in young or new injectors

Place, year SampleAnti-HCV

prevalence

China, 2004 597 young IDUs 72%

New York, 2003 630 young IDUs 44%

London, 2002 428 young IDUs 44%

San Francisco, 2002 776 young IDUs 39%

Vancouver, 2002 234 young IDUs 46%

Chicago, 2002 702 young or new

27%

Seattle, 2001 383 new injectors

41%

Baltimore, 1996 312 new injectors

77%

Enrollment 1 year later

HCV Incidence25 anti-HCV negative IDUs followed for 1 year

5 become anti-HCV positiveHCV Incidence=5/25, or 20%

0 12 months6 months

Person

Years1

1

1

1

½

Person-years:

A

B

C

D

E

Time in the study4 ½

Incidence of HCV & HIV in IDUs

Location

Year

HCV Incidence

HIV Incidence

Amsterdam 1991 10% 5%

Geneva 1992 12% 1%

Rome 1993 9% 0%

Vancouver 1997 29% 5%

Seattle 1999 27% 0.2% US multi-site 1999 10% 1% S. China 2003 38% 7% New York 2003 21% 0.4%

HCV incidence in young or new injectors

Place, year SampleAnti-HCV incidence

China, 2004 159 young IDUs

38%

New York, 2003 141 young IDUs

21%

London, 2002 151young IDUs 42%

San Francisco, 2002 195 young IDUs

25%

Vancouver, 2002 76 young IDUs 42%

Chicago, 2002 353 young/new 10%

Seattle, 2001 121 new injectors

21%

Time to HCV seroconversion in a cohort

of Seattle IDUsHagan H, Thiede H, & Des Jarlais DC.

Epidemiology, 2004.

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

0%

20%

40%

60%

80%

100%

0 8 16 24 32 40 48

Time since study enrollment (months)

%

rem

ain

ing

HC

V-n

egat

ive

new injectorsothers

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)

New injectors

HCV- HCV+

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)

Evaluates risk of disease related to– Risk factor – Participation in a prevention program

Cooker/cotton sharing

RR=4.0 IDUs who share cooker/cotton are 4 times more likely to get HCV than those who do not

Age > 40 RR=0.4 IDUs older than 40 are only 40% as likely as younger injectors to get HCV

Example: Studies of HCV incidence in IDUs

Methadone and HCV prevention

Citation Sample Results

Rezza et al, 1996

Italian IDUs MMTP somewhat protective against HCV

Crofts et al, 1997

Melbourne IDUs

No effect on HCV incidence

Hagan et al, 2001

Seattle IDUs No effect on HCV incidence

Thiede et al, 2000

Seattle IDUs Remaining in MMTP somewhat protective against HCV

Needle exchange & HCV prevention

Citation Sample Results

Hagan et al, 1995

Tacoma IDUs Needle exchange users 6 times LESS likely to get HCV

Hagan et al, 1999

187 Seattle IDUs,

No difference in HCV incidence

Mansson et al, 2000

698 Swedish IDUs

HCV incidence 26% in exchange users – no comparison group

Des Jarlais et al, 2003

150 NYC Young IDUs

No difference in HCV incidence

Disinfectant bleach & HCVCitation Sample Results

Hagan et al, 2002

Seattle IDUs

HCV seroconversion 27% in bleach users vs. 31% in others

Kapadia et al 2002

IDUs in 6 US cities

Those who used bleach all the time only 40% as likely to seroconvert to HCV+

Hagan et al, 2003

Seattle IDUs

Those who used bleach all the time 40% more likely to seroconvert to HCV+

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

0

10

20

30

40

50

60

% HIV+

Source: DC Des Jarlais et al

Recent HIV Incidence StudiesNew York City IDUs

• 13 separate studies• Range from 0 to 3/100 person-

years• Weighted average > 1/100 person

years

HCV SeroprevalenceNYC IDUs

1990-91 2000-01

90% 66%

Source: DC Des Jarlais et al

HIV Seroprevalence NYC IDUs, 2002

Whites HispanicsAfrican-

Americans

5% 8% 25%

Source: DC Des Jarlais et al

HCV Seroprevalence NYC IDUs 2000-01

Whites HispanicsAfrican-

Americans

66% 66% 67%

Source: DC Des Jarlais et al

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

1990-91 2000-01

71% 39%

Source: DC Des Jarlais et al

Trends in Hepatitis C PrevalenceIn 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 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 • 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• 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

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