Elimination of hepatitis C among people who inject drugs in Europe
will require simultaneous scale-up of direct-acting antiviral treatment,
needle and syringe programmes (NSP) and opioid substitution treatment
(OST), and a re-think of attitudes to drug policy and harm reduction in
Central Europe, according to a modelling study led by researchers from
the University of Bristol.
The study findings, published in advance online by the Journal of Hepatology,
show that although increasing the number of people treated for
hepatitis C may result in large reductions in prevalence in countries
with low hepatitis C virus (HCV) prevalence, it will have little impact
on new infections in most settings.
Elimination of hepatitis C – which the World Health Organization
defines as a 65% reduction in HCV-related deaths and a 90% reduction in
new infections by 2030 – will depend on both treatment of existing
chronic infections and the prevention of new infections.
Some experts see the potential to eliminate hepatitis C transmission
in some populations by diagnosing and treating everyone with hepatitis C
but this would depend on treatment being affordable and accessible for
all. Rapid elimination through treatment alone also depends on the
screening of the population to identify people with hepatitis C and good
engagement in health care.
In the European Union, 3.6 million people were estimated to have
chronic HCV infection in 2016. Estimates of the number of people with
hepatitis C who inject drugs are difficult to arrive at, due to lack of
surveillance systems, lack of information about possible sources of
exposure and uncertainty about the size of the current injecting
population in European countries.
The European Monitoring Centre for Drugs and Drug Addiction estimates
that the United Kingdom has the largest number of current injectors in
the European Union – over 120,000 – compared with 9900 current injectors
Researchers at the University of Bristol and colleagues at other
European Union universities developed a model to assess the impact of
varying levels of treatment coverage, OST and clean needle and syringe
provision on HCV prevalence and incidence up to 2026. They wanted to
understand the relative contributions of treatment and prevention to HCV
incidence and to determine what levels of treatment and prevention
coverage might be necessary in different settings in order to deliver
substantial reductions in HCV incidence.
The model used prevalence and population data for eleven cities or
countries, reported between 2009 and 2014. The prevalence of HCV among
people who inject drugs ranged from 27% in Slovenia to 66% in France,
67% in Scotland and 76% in Finland. The size of the drug-injecting
population also varied, from around 6000 people in Slovenia to 80,000 in
France. The model did not include all European countries because the
object was to compare settings, with different characteristics, rather
than arrive at a single estimate for the European Union.
The model compared enhanced rates of treatment and prevention
coverage compared to the status quo. It showed that in eight of the
eleven sites included in the model HCV prevalence would fall by less
than 5% over a decade among people who inject drugs at current rates of
treatment uptake. Only in Amsterdam, the Czech Republic and Slovenia
would current rates of treatment lead to greater decreases in HCV
Even if treatment coverage doubled, this would not be sufficient to
reduce prevalence in countries with the highest prevalence, such as
Sweden and Finland. In countries with moderate HCV prevalence, such as
Scotland, doubling treatment coverage would result in reductions in
prevalence of between 11.6% and 23.5%. To achieve substantial reductions
in prevalence it would be necessary to treat at least 5% of the
drug-injecting population each year. This scale of treatment would
achieve a 99% reduction in prevalence in the Czech Republic and
Slovenia, but a large reduction in prevalence would only come about in
other countries if the coverage of OST and NSP reached 80%.
Achieving HCV incidence below 2% would require treatment coverage to
be increased 17 times in Sweden and 200 times in Finland above current
levels without scaling up OST and NSP. Even with the scale-up of OST and
NSP, treatment coverage would need to expand tenfold in Sweden and 159
times above current levels to force HCV incidence below 2%.
“Reducing HCV incidence to <2% by 2026 requires little action in
Amsterdam, Czech Republic and Slovenia, whereas in Belgium, Denmark,
Hamburg, Norway, and Scotland it will require at least a fivefold
increase in the current HCV treatment rates, or 1.8 to 4.7-fold if OST
and NSP are scaled up,” the authors conclude.
They also point out that better surveillance of prevalence and new
infections will be needed to achieve elimination, pointing out that the
costs of surveillance are trivial in comparison to drug costs but
necessary for HCV 'treatment as prevention' to be validated as
"Their findings reiterate the importance of high
prevention coverage as a primary method of reducing incidence and
prevalence," write Margaret Hellard and colleagues from Monash
University, Melbourne, in an accompanying editorial. They draw attention
to the need to engage people who inject drugs in harm reduction
services and health care, as well as the development of models of care
that are acceptable to people who inject drugs, as essential for high
uptake of treatment.