Large number of young Canadian injecting drug
users coinfected with HIV and HCV
A high proportion of injecting
drug users under the age of 29 in one of
Canada's largest cities are coinfected with HIV
and hepatitis C virus (HCV), according to a
study published in the June 1st edition of the
Acquired Immune Deficiency Syndromes.
The investigators also found that coinfected
young people had a median age of only 24 years,
had only been injecting drugs for a few years,
and that women and individuals of aboriginal
origin were at particular risk of coinfection.
The investigators warn that HIV/HCV coinfection
is likely to become ubiquitous amongst young
drug users in high drug use areas.
Investigators from the Vancouver Injection Drug
Users Study (VIDUS) wished to establish the
prevalence and incidence of HIV and HCV
coinfection amongst drug users under 29 years of
age in the city. They also wished to establish
the sociodemographic characteristics and risk
factors for coinfection.
Since May 1996 the investigators have been
gathering prospective data from a cohort of 1478
injecting drug users recruited in the Downtown
Eastside area of
Vancouver, an epicentre of injecting drug use in
the city. At recruitment and at six monthly
intervals, individuals completed a questionnaire
detailing their sociodemographic background and
drug taking and sexual behaviours. HIV and HCV
tests were also administered at baseline and at
the six monthly follow-up visits.
Of the 1478 individuals enrolled in the cohort,
479 were aged under 29 years and were included
in the investigators' current analyses. The
young cohort members had a median age of 24
years, and at baseline 78 (16%) were coinfected
with HIV and HCV. In addition, 211 were
monoinfected with HCV at baseline and 176 were
monoinfected with HIV.
The coinfected young people had a median age of
26 years, and had been injecting drugs for a
median duration of seven years. Monoinfected or
uninfected young people had a median age of 24
years and had been injecting drugs for a median
of three years.
Coinfected individuals at baseline were more
likely than moinfected or uninfected young
injecting drug users to be female (62% versus
42%, p=0.002), aboriginal (45% versus 22%,
p<0.001), have a history of sexual abuse (53%
versus 38%, p=0.014), reside in a drug use
epicentre (69% versus 46%, p<0.001), to have had
more than 100 lifetime sexual partners (59%
versus 31%, p<0.001), be involved in the sex
trade (63% versus 38%, p<0.001) and to inject
cocaine (63% versus 38%, p=0.012).
Follow-up data were available for 297 young
injecting drug users, and of these 45 (15%)
became coinfected with either HIV or HCV. The
incidence rate of coinfection was 5.2 per 100
person-years. The median age of seroconvertors
was 24 years, and they had been injecting for a
median of three years. The majority (55%) were
female, and 40% were of aboriginal origin.
Being female (risk ratio [RR] 1.12), aboriginal
(RR 1.99), living in an injecting drug use
epicentre (RR 1.98), injecting heroin more than
once daily (RR 3.46), injecting cocaine (RR
4.05), and sharing needles (RR 2.14) were all
associated with seroconversion with a second
infection. Accessing methadone replacement
therapy was, however, found to protect against
the risk of coinfection (RR 0.25).
"The number of youth HIV and HCV coinfected
identified by this study is concerning," state
the investigators. They were particularly
alarmed by the finding "that the median age of
youth being coinfected was 24 years and they had
been injecting for a median of only three years."
They add that coinfection was "concentrated
among young female and aboriginal youth engaged
in sex trade work and living in the [injecting
drug use] epicentre." The investigators are
fearful that these factors "do not bode well for
the future of coinfection without the immediate
implementation of a comprehensive evidence-based
prevention strategy for high-risk youth."
Particular attention is drawn by the
investigators to the finding that 63% of
coinfected young women were involved in sex
trade, which "begs the question why, given the
overwhelming vulnerability of young women
involved in the sex trade, there are not
resources available such as 24-hour services to
access clean needles, inject safely, and seek
Noting that access to methadone replacement
therapy in the previous six months was
protective against coinfection, the
investigators emphasise that more needs to be
done to make methadone more accessible to young
and that more efforts should be made to provide
harm reduction services such as needle
exchanges, safe injection programmes, health
care, and drug treatment.
The investigators conclude that their data are
alarming, and suggest that HIV/HCV coinfection
amongst young injecting drug users "is no small
problem and that coinfection may become
ubiquitous for young [injecting drug users]
living in endemic areas."
Miller CL et al.
The future face
of coinfection: prevalence and incidence of HIV
and hepatitis C virus coinfection among young
injection drug users. J Acquir Immune
Defic Syndr 36: 743-749, 2004.