Infection with HIV and hepatitis C virus among injecting drug users in a prevention setting: retrospective cohort study.
OBJECTIVE
To estimate the incidence of HIV and hepatitis C virus and risk factors for seroconversion among a cohort of injecting drug users.


METHODS
Retrospective cohort study.


METHODS
Primary healthcare facility in central Sydney.


METHODS
Injecting drug users tested for HIV-1 antibody (n=1179) and antibodies to hepatitis C virus (n=1078) from February 1992 to October 1995.


METHODS
Incidence of HIV-1 and hepatitis C virus among seronegative subjects who injected drugs and underwent repeat testing. Demographic and behavioural risk factors for hepatitis seroconversion.


RESULTS
Incidence of HIV-1 among 426 initially seronegative injecting drug users was 0.17/100 person years (two seroconversions) compared with an incidence of hepatitis C virus of 20.9/100 person years (31 seroconversions) among 152 injecting drug users initially negative for hepatitis C virus. Incidence of hepatitis C virus among injecting drug users aged less than 20 years was 75.6/100 person years. Independent risk factors for hepatitis C virus seroconversion were age less than 20 years and a history of imprisonment.


CONCLUSIONS
In a setting where prevention measures have contributed to the maintenance of low prevalence and incidence of HIV-1, transmission of hepatitis C virus continues at extremely high levels, particularly among young injecting drug users.
van Beek
I
I
Kirketon Road Centre, PO Box 22, Kings Cross, New South Wales 1340, Australia. ivanbeek@ozemail.com.au
Dwyer
R
R
Dore
G J
GJ
Luo
K
K
Kaldor
J M
JM
D000328:Adult; D017677:Age Distribution; D000368:Aged; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control; D006526:Hepatitis C / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control; D018937:Hepatitis C Antibodies / Q000032:analysis; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009517:New South Wales / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000453:epidemiology*
D018937:Hepatitis C Antibodies