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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 Journal of 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 care."

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 people
, 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.