Hepatitis C Virus Acquisition among Injecting Drug Users: A Cohort Analysis of a National Repeated Cross-sectional Survey of Needle and Syringe Program Attendees in Australia, 1995–2004

Abstract

High hepatitis C virus (HCV) prevalence has been documented among many injecting drug user (IDU) populations worldwide; however, there is limited published data on trends in incidence of infection in these epidemics over time. To address this, we used a novel method of analyzing data collected via repeat, cross-sectional sero-surveys by injection initiation cohorts to investigate trends in HCV seropositivity among a population of needle and syringe program (NSP) attendees in Australia between 1995 and 2004, and thereby infer annual incidence trends. Injection initiation cohorts were defined by their time of entry into the IDU population. We also investigated the associations between HCV antibody seroprevalence and risk factor data, and trends in risk factor data over the decade. Approximately 20,000 NSP attendees participated in the study over the 10-year period. Within each injection initiation cohort, we found an increase in HCV prevalence over time, with prevalence appearing to reach saturation around 90%. There was little indication that the slopes of increase had changed with more recent initiation cohorts. While duration of injecting was most strongly associated with HCV seropositivity in this study, we also found that self-reported history of needle and syringe sharing and imprisonment were independently associated with higher HCV prevalence regardless of duration of injecting, with the exception of IDUs who have 15 or more years injecting experience. In this group, recent risk behavior had no relationship to prevalence. In summary, our findings suggest a persistent HCV epidemic despite significant harm reduction efforts in Australia since the mid-1980s, with HIV incidence effectively constant in successive initiation cohorts.

The role of social networks and geography on risky injection behaviors of young persons who inject drugs

“…Studies frequently report associations between HCV infection and injection duration, injection frequency, cocaine injection, and sharing of syringes and other injection paraphernalia among persons who inject drugs (PWID; Boodram et al, 2010; Falster et al, 2009; Garfein et al, 1996; Hagan et al, 2001; Pouget et al, 2012; Thorpe et al, 2000). Recent trends show that although both HIV (Broz et al, 2014; Centers for Disease Control and Prevention, 2009) and HCV (Amon et al, 2008) prevalence have steadily declined among older PWID, high-incidence of HCV infection (Page et al, 2009; Zibbell et al, 2015) and HCV outbreaks among younger PWID (Centers for Disease Control and Prevention, 2011; Leuchner et al, 2008) are occurring.…”

Status of hepatitis C virus infection in lung cancer patients

“…HCV prevalence can reach 30% to 60% within a few years of its first appearance in a population of injection drug users and achieve greater than 90% in a mature epidemic (24)(25)(26)(27)(28). In this study, there was no history of injection drug users in patients with anti-HCV (+) and anti-HCV (-).…”

Higher HCV antibody prevalence among Indigenous clients of needle and syringe programs

“…14,16,18 Prison NSPs operating in six European jurisdictions have had favourable results, with stable or decreased drug use and decreased reports of drug initiation, decreased equipment sharing and no reported cases of HCV, hepatitis B or HIV transmission. 19 Whereas HCV seroprevalence was higher among Indigenous participants, HIV seroprevalence rates were around 1% for both groups. Given this study has demonstrated higher risk behaviour associated with HCV seroprevalence, there is an urgent need for a heightened awareness among Indigenous PWID highlighting the risks of HIV transmission.…”