Providing hepatitis C virus (HCV)
therapy with direct-acting antivirals (DAAs) to people who inject drugs can
achieve rapid reductions in community prevalence of viraemia, according to
Australian research published in the Journal
of Hepatology. Uptake of HCV treatment increased from 10% to 41% after
unrestricted access to DAAs was rolled out in March 2016, and the proportion of
viraemic patients fell from 43% to 25%.
The authors
believe their findings have significance for the World Health Organization
(WHO) target of eliminating HCV as a public health threat by 2030.
“The elimination
of HCV as a global public health threat will require strategies that provide
DAA access to high-risk populations, often those who are highly marginalised in
society,” comment the investigators. “This study provides evidence that
relatively high rates of HCV treatment can be achieved among PWID [people who inject drugs] when DAA
therapy is made available without restriction.”
All-oral HCV
therapy using DAAs can achieve cure rates in excess of 95% with minimal
toxicity. The availability of DAAs was instrumental in the development of the
WHO target to eliminate HCV as a global public health threat by 2030. For
elimination to be achieved, 80% of people with chronic HCV will need to
receive DAA therapy, achieving a 65% reduction in HCV-related mortality and a
80% fall in HCV incidence.
Globally, people who inject drugs are
one of the communities most affected by HCV. Stigmatised, criminalised and
marginalised, people who inject drugs often face significant barriers accessing HCV therapy. But
the achievement of the WHO elimination target will only be possible with
widespread rollout of DAAs with corresponding reductions in the prevalence of
viraemia in the most affected communities.
Starting in March
2016, unrestricted, subsidised access to DAA therapy was provided to all
people with chronic HCV infection in Australia. Investigators analysed
surveillance data collected from people who inject drugs between 2015 and 2017 to assess the
impact of DAA rollout on treatment uptake and the proportion of people with
HCV viraemia.
People were
interviewed about their use of therapy and its outcome. Blood samples were also
obtained to determine the prevalence of HCV antibodies and viraemia.
The annual study
samples included ranged in size between 1995 and 2380 individuals. Approximately
a third of participants were women, between 1.4% to 2.1% were HIV positive and
0.5% to 1% had HIV and HCV co-infection.
HCV antibody
prevalence declined significantly from 57% in 2015 to 49% in 2017 (p <
0.001).
Spontaneous HCV
cure was observed in between a fifth and a quarter of people with evidence of
HCV infection.
Among people eligible for treatment (excluding individuals with spontaneous cure), treatment
initiation rates increased from 10% in 2015, to 17% in 2016, and to 31% in
2017.
In the overall
sample, prevalence of HCV viraemia declined from 43% in 2015, to 32% in 2016,
and to 25% in 2017.
Trends in
treatment initiation and viraemia were both highly significant (p < 0.001).
HCV re-infection
or relapse was observed in 18 people. “The clearly demonstrated potential for
PWID to be reinfected with HCV following successful DAA therapy is of concern,”
comment the authors. “We believe the best approach to reinfection is enhanced
harm reduction and rigorous monitoring for reinfection post-treatment with
access to DAA therapy for retreatment.”
Older age (above
44 years vs below 37 years) was strongly associated with DAA treatment, so too
history of opioid substitution therapy (aOR = 2.06; 95% CI, 1.30-3.26, p =
0.002).
“Australia is in
an enviable position, with unrestricted subsidised access to DAA therapy among
PWID and well established, high coverage harm reduction and prevention
programs,” conclude the authors. “Findings from this study, including rapid
uptake of DAA therapy and reduced viraemic prevalence of active HCV infection
among PWID are encouraging and provide proof of concept that eliminating HCV as
a public health threat through HCV treatment as prevention is feasible.”