The 5th International Symposium on Hepatitis Care in
Substance Users (INHSU 2016) got underway yesterday with an overview of the
epidemiology of hepatitis C virus (HCV) among people who inject drugs and a
look at public health and harm reduction approaches to preventing, treating and
managing hepatitis C in this often neglected population.
The conference, sponsored by
the International Network on Hepatitis in Substance Users, brought together more than 400 researchers, healthcare providers and advocates
for people who use drugs and people living with hepatitis C. The gathering
included several speakers from drug user organisations in Europe and
Australia.
Olav Dalgard of Akershus University Hospital opened the
meeting, noting that the conference is particularly important at this time due
to the advent of effective new interferon-free direct-acting antiviral
treatment that can cure almost all people with hepatitis C in a few months with
few side-effects.
With the medical research puzzle largely solved, the
focus now turns to broadening access to treatment for the people who need it
most, which prominently includes people who inject drugs. HCV is
efficiently transmitted via shared needles and other injection equipment, and a
large proportion of people who inject drugs contract the infection soon after they start to
inject.
"The science is
clear," said INHSU president Jason Grebely of the Kirby Institute at the
University of New South Wales. "We now need to focus on overcoming
barriers to access, and harness latest research to implement programs that
work."
Sharon Hutchinson of Glasgow Caledonian University
gave an overview of the burden of HCV infection among people who inject drugs. Current estimates
suggest that 12.2 million people worldwide currently inject drugs, but reliable
data is not available from all areas and the actual number could range from 8
to 22 million. Of these, an estimated 6.3 million have HCV and 1.6 million have
HIV. But it is critical not to overlook people who have ever injected drugs in
the past – a much larger population.
Viral hepatitis has
become a leading cause of death and disability worldwide, now exceeding HIV, malaria and
tuberculosis. While mortality among people with HIV dropped dramatically
following the introduction of effective antiretroviral therapy in the
mid-1990s, Hutchinson said it remains to be seen whether we will
see HCV-related deaths fall to the same extent after the introduction
of direct-acting antivirals.
People who inject drugs who have hepatitis C often have other
health risk behaviours including heavy alcohol use and poor diet, which raises
the risk of liver disease progression and death due to other cause. Deaths due
to overdose are also common.
"Attaining sustained virological response may be
an opportunity to focus on other health risks," Hutchinson suggested.
"To eliminate liver disease burden we will need a multi-pronged approach,
scaling up therapy but also tackling wider health risk behaviours."
Speakers also addressed primary HCV prevention among people who inject drugs who do not have the infection. A growing body of research supports the
effectiveness of harm reduction approaches, but these are not yet accessible to
all who need them, even in many high-income countries.
Holly Hagan of New York University reviewed research
showing that a high coverage of needle and syringe programmes plus widely
available opioid substitution therapy (OST) can reduce the risk of HCV
transmission by about 70%; inadequate coverage, however, is much less
effective.
Hagan also noted that sharing cookers, cotton filters
and rinse water for preparing drugs can transmit HCV, along with needles and
syringes. In fact, sharing cookers and cotton was an even higher risk than
needles in some studies because more people do it. Yet while needle and syringe
provision is now an accepted public health intervention, fewer programmes provide
an adequate supply of related equipment.
The public health field increasingly recognises the
benefits of OST, but it remains politically controversial
in some areas. Johan Franck of the Karolinska Institute gave an overview of the
history of and research supporting OST using methadone, buprenorphine and
prescription heroin. Unfortunately, stimulant substitution has so far not
proven very effective.
Matthew Hickman of the University of Bristol gave a
talk on HCV treatment-as-prevention. Controlled trials in the HIV field have
shown that antiretroviral treatment that reduces viral load to an undetectable
level makes it nearly impossible to transmit HIV. Hepatitis C treatment should
theoretically be even more effective in this regard, as it actually eliminates
HCV, while HIV treatment only suppresses viral replication while on therapy.
Although there is not yet empirical evidence that HCV
treatment will reduce transmission, modelling studies indicate that relatively
modest scale-ups of treatment could have a major impact on hepatitis C
epidemics, influenced by factors such as HCV prevalence in a given population.
As such, guidelines increasingly recommend prioritising treatment for people
who are likely to transmit HCV – such as active drug users who share equipment –
in addition to people with advanced liver disease.
Ultimately, harm reduction approaches and hepatitis C
treatment may not be enough to halt epidemics, and researchers are avidly
seeking an HCV vaccine. Andrea Cox of Johns Hopkins University reviewed this
research to date. John-Arne Røttingen of the Norwegian Institute of Public
Health followed with a discussion of how lessons from the Ebola epidemic can
inform the design of hepatitis C trials.
Developing an HCV vaccine is difficult because the
virus is highly variable. While we know that HCV does not confer full
protective immunity against reinfection, evidence indicates that some
protective immunity does develop, and it appears to get stronger with each
subsequent infection. A preventive vaccine candidate is now in clinical trials
with data due in early 2017.
"We have a unique opportunity, if we can combine
treatment and a vaccine, to accomplish what we can't do with other disease
using one or the other," Cox concluded.
Several speakers emphasised the importance of
involving people who inject drugs in the design of research and the development
of prevention and treatment programmes.
"We have been too long neglected and seen as a
group that can be ignored," said Ronny Bjørnestad from proLAR, a Norwegian
organisation for people on OST. "We will no longer tolerate treatments
with side effects. We have to increase prevention, start treating people fast,
and give treatment to people who are at risk of infecting others, as well as
for their own health."
Saga Rönnlund ended the day with a presentation of Liver Or Die, a peer education
initiative created by the Swedish Drug Users Union.
"Just as myths are spread we can spread the
opposite – correct information," she said.