INHSU 2015 highlights hepatitis C prevention and treatment for people who inject drugs

An international group of researchers, healthcare providers, advocates, people who use drugs and people living with hepatitis C are gathering this week in Sydney for the 4^th International Symposium on Health Care in Substance Users, focusing on hepatitis C prevention, care and treatment for injection drug users. The full program, with links to many of the presentations, is available online.

The conference began with an overview of the epidemiology of hepatitis C virus (HCV) infection among people who inject drugs (PWID). HCV is efficiently transmitted via shared needles and other injection equipment – more so than HIV – and a large proportion of people who inject drugs become infected with HCV soon after starting to inject.

As Sarah Larney of the University of New South Wales (UNSW) explained, it is important to have good estimates of the number of drug injectors, as well as local HCV incidence (new infections), prevalence (total infections), duration of current and past injecting and how many share equipment. Understanding prison populations is also key as incarcerated people have high rates of hepatitis C.

One study found that in settings with long injecting durations (that is, a low cessation rate) HCV treatment may have more impact on the epidemic, while in settings with short injecting durations needle exchange programmes and opiate substitution therapy (OST) may play a greater role.

Harm reduction interventions are key to controlling hepatitis C. As Eliot Albers of the International Network of People Who Use Drugs emphasised, people are not infected through injection drug use itself – they're infected through shared injection equipment. Yet according to Lisa Maher of UNSW, about half of all countries still do not have needle and syringe exchange programs, and the overall global rate of distribution works out to just 22 needles per user per year.

Lucy Platt of the London School of Hygiene and Tropical Medicine presented findings from a meta-analysis of the effects on HCV incidence of needle exchange programs and OST using methadone or buprenorphine on HCV incidence.

Looking at 15 studies with more than 4,000 total person-years of follow-up, they found that OST reduced the risk of HCV infection by 39% overall. OST appeared to have somewhat less effect for women. In an evaluation of seven studies of needle and syringe exchange with more than 1,000 total person-years of follow-up, programmes in Europe were associated with a 58% reduction in HCV acquisition. However, looking at a smaller subset of programmes in the United States, exchanges were actually associated with higher HCV risk.

Platt's team concluded that there is strong evidence that OST reduces HCV transmission. The evidence for needle exchange programmes is weaker, underlining the importance of combining opioid substitution and needle exchange, and the need for exchanges to reach a large proportion of local injectors.

Julie Bruneau of the University of Montreal and others described changes over time in injection drug use and populations who inject drugs. These findings emphasise how harm reduction interventions have to change to meet evolving needs. One area of unmet need is effective addiction management for other types of drugs, as OST is only for heroin and other opiates. About a third of drug injectors are dependent on non-opioids, according to Philip Bruggmann of the Arud Centres for Addiction Medicine in Switzerland.

A number of presentations at the conference focused on hepatitis C treatment for people who inject drugs, with an emphasis on new interferon-free direct-acting antiviral therapies. (Treatment studies from the meeting will be described in more detail in a forthcoming report.)

Jordan Feld of the University of Toronto gave an overview of the current state of treatment, concluding that while current therapies produce high cure rates – generally 90% or better – we do not yet have a 'perfectovir'. Research is still needed on how well the new treatments work for people who are current active drug injectors, as most PWID studies have looked at those on OST. Simpler treatment regimens could help increase the pool of hepatitis C treaters beyond hepatologists and infectious disease specialists.

Expanded hepatitis C treatment is expected to prevent liver disease progression among people who inject drugs. Over years or decades chronic HCV infection can lead to advanced disease including liver cirrhosis, decompensation (when the liver can no longer perform its vital functions), hepatocellular carcinoma (HCC) and end-stage liver disease requiring a transplant.

Reem Waziry of the UNSW Kirby Institute presented findings from a study of trends in end-stage liver disease among injection drug users with HCV who either were or were not receiving OST. Rates of decompensated cirrhosis and HCC rose overall between 2001 and 2013, but people who had never received OST had both a higher rate and a steeper rise in both conditions compared to those who had ever been on OST.

In addition to benefitting the health of people with hepatitis C, effective treatment also means that cured patients will not transmit HCV – a concept dubbed 'treatment as prevention'. Modelling studies indicate that widespread treatment of populations including prisoners and drug injectors could dramatically reduce HCV incidence.

But Magdalena Harris of the London School of Hygiene and Tropical Medicine cautioned against over-emphasising the prevention benefits of HCV treatment, stressing that people who inject drugs can find it alienating as they do not want to be viewed as disease transmitters and are concerned about the prospect of coerced treatment. "Treatment as prevention will fail without prevention as prevention," Harris said.

Jude Byrne of the Australian Injecting and Illicit Drug Users League, Carla Treloar of UNSW and others discussed some of the barriers to hepatitis C diagnosis, care and treatment – among them stigma and discrimination against people who use drugs. Too often researchers "ignore the intelligence and agency of PWID," Byrne said.

"People may be unable or unwilling to jump through hoops to prove they deserve treatment," Treloar added. "We need to provide care where people are, not where we want them to be."

Finally, as with all recent meetings addressing hepatitis C, the cost and cost-effectiveness of new HCV therapies was a major topic. To date, high drug prices have led many government payers and private insurers to restrict treatment to the sickest patients – and in some cases to exclude people who have recently used drugs or alcohol.

Treatment that averts long-term consequences such as liver cancer and transplantation may be cost-effective in the long run, but the immediate cost of treating everyone with HCV is more than most payers can bear.

Yet treating hepatitis C in people who inject drugs is the most cost effective way to address the sharp increase in liver disease and death resulting from hepatitis C infection, according to experts.

"Without greatly enhanced treatment access, high level hepatitis C transmission will continue, and the rising burden of liver disease will lead to substantial costs to healthcare systems," Jason Grebely of the Kirby Institute said in a UNSW press release. "Treatment of people who use drugs with hepatitis C saves lives and is cost-effective. We need to step up treatment access for this group as a major public health priority…Treating hepatitis C in people who use drugs will not only reduce the future potential disease burden and reduce costs to our healthcare system. It is also an important first step towards elimination of HCV."

"Deaths and advanced liver disease associated with long term hepatitis C infection are dramatically increasing in Australia. We have not just effective but highly cost-effective therapies available to redress this situation," added Annie Madden of the Australian Injecting and Illicit Drug Users League. "At the end of the day, however, it is the negative impact of stigma, discrimination, and criminalization that is preventing people who need it most from accessing any kind of care in relation to their hepatitis C. This needs to change and it needs to change now."

Coinciding with the conference the International Journal of Drug Policy launched its October 2015 special issue addressing hepatitis C among people who inject drugs, including recommendations for care and treatment. The guidelines encourage providers to offer treatment regardless of liver disease severity along with a comprehensive package of social support and harm reduction services. Other articles in the issue – which are free online – look at expanding access to prevention and treatment, liver disease progression, hepatitis C treatment as prevention and successful treatment models.