Editorial Commentary: Hepatitis C Virus Testing and Drug Use in North America; Is There More Than Meets the Eye?

Abstract

(See the Major Article by Bruneau et al on pages 755–61.) The hepatitis C virus (HCV) epidemic is a major public health challenge in North America. An estimated 5–7 million persons are infected with HCV, which is causing an escalating amount of morbidity and mortality due to cirrhosis and hepatocellular carcinoma [1–3]. In 2007, it was estimated that the death rate from HCV infection exceeded that of human immunodeficiency virus (HIV) infection in the United States for the first time [4]. Drug users, particularly people who inject drugs (PWID), have been heavily impacted by HCV infection and continue to experience incident infections. Efforts to decrease HCV among PWID have included educational and behavioral interventions, needle and syringe exchange programs, legalized syringe purchase, supervised injection venues, and substance abuse treatment including opiate replacement therapy [5]; however, these strategies have not been uniformly delivered or accessible. In fact, there have been recent reports of HCV outbreaks among young drug users who are transitioning from use of prescription opiates to injecting heroin [6–8], revealing the urgent need to implement comprehensive prevention measures [9]. In this issue of Clinical Infectious Diseases, Bruneau et al present data from a longitudinal cohort of HCV- and HIV-negative PWID in Montreal [10]. One-third of study participants became HCV infected during the follow-up period, for an incidence rate of 14.4 per 100 person-years. The novel finding of this study is that drug-using behaviors, namely, injection of heroin and cocaine, decreased among persons who seroconverted and learned of their HCV infection through regularly scheduled HCV testing. No such change was observed among those who tested negative for HCV. Both groups showed significant reductions in syringe sharing over time, although this finding was more prominent among the HCV seroconverters. Importantly, the change in drug using behaviors among seroconverters was not transient but appeared to be sustained during the follow-up period of several years. Although we cannot assume causality in the findings, the study highlights the importance of HCV testing as a catalyst for behavior change. The Centers for Disease Control and Prevention (CDC) recently expanded their HCV testing recommendations with the hope of reducing the number of persons who are unknowingly infected. In addition to recommending HCV testing for PWID, the CDC now recommends at least 1-time HCV testing to all persons born between 1945 and 1965, as the majority of prevalent HCV cases are among this birth cohort [11]. While this is a significant expansion over previous testing recommendations, it does not adequately address the need for HCV testing among PWID, particularly those born after 1965. We know from previous experience that HCV testing based upon the identification of risk behaviors, as would be the case for an injector born after 1965, is not sufficient. We have been through this before—with the HIV epidemic. Testing that is based on the acknowledgement of risk by the patient or the assumption of risk by the healthcare provider is often ineffective. Routinely offering testing on a voluntary basis in appropriate settings is a more effective approach for infectious diseases that carry stigma and that are associated with drug and sexual risk behaviors [12]. Routine testing for HCV needs to be explored in settings and venues where PWIDs can be found, including correctional facilities, syringe exchange programs, methadone and buprenorphine treatment centers, and residential substance abuse treatment centers, and in emergency departments. PWID need regular and frequent HCV testing in an effort to identify newly acquired cases, link persons with a positive antibody test to confirmatory nucleic acid testing, provide linkage to medical care for infected persons, and provide education and risk reduction counseling to all persons undergoing testing with the goal of preventing future infections. The change in injection behaviors after testing positive for HCV that was observed in this study strongly supports the expansion of HCV testing. Changes in risk behaviors after testing positive for HIV infection have been observed in multiple studies over the course of the HIV epidemic [13, 14]. However, seeing a similar phenomenon with sustained effect after HCV testing is a new and important finding. The study did not measure other events that may have contributed to a reduction in injection of heroin and cocaine such as becoming newly engaged with a healthcare provider and/or drug abuse treatment. Further research is needed to elucidate which interventions or experiences promote safer or less injection drug use among persons testing positive for HCV. To maximize the prevention impact, initial antibody testing must also be coupled with mechanisms to ensure completion of confirmatory testing and linkage to HCV evaluation and treatment for those with confirmed infection. The emergence of new anti-HCV treatments that are more effective and more tolerable are an important and timely incentive to expand HCV testing efforts. The study highlights other important findings that are relevant for HCV prevention programs. Even without the fear and uncertainty that may accompany a new diagnosis of HCV, testing was also associated with a reduction in syringe sharing among those who remained HCV negative. Although changes in syringe sharing over time among cohort participants who did not have regular HCV testing was not assessed, it is plausible that regular HCV testing with accompanying risk reduction counseling was a significant contributor to this behavior change. The potential prevention benefit of regular HCV testing and counseling increases dramatically if there is a sustained decrease in injection practices that account for the majority of new HCV infections, regardless of HCV status. Unfortunately, despite learning of their HCV infection, there was no reduction in alcohol use among cohort participants who tested positive for HCV. Alcohol use dramatically accelerates liver disease in combination with HCV infection. The CDC now recommends that all persons testing positive for HCV undergo a brief alcohol intervention [11], yet we do not know which interventions are most effective in reducing the deleterious effects of alcohol consumption among HCV-infected PWID. This study supports HCV testing as a cornerstone of HCV prevention. Regular HCV testing was associated with healthy behavior change among persons testing positive and negative. These findings will help invigorate HCV testing implementation efforts and advance the research agenda, which must include understanding the barriers to expanded HCV testing among PWID, the motivating factors that underlie behavior change, and how to effectively integrate evidence-based alcohol interventions in HCV testing programs.