Exclusive use of low dead-space syringes is associated with
a lower prevalence of hepatitis C virus (HCV) in people who inject drugs, especially in people who
began injecting drugs recently, a study in the United Kingdom has found. The
study is published in the journal Drug
and Alcohol Dependence.
Low dead-space syringes (LDSS) are syringes with needles attached. They retain far less blood after injecting than syringes
with detachable needles. By retaining less blood, LDSS may
reduce the risk of hepatitis C transmission by sharing of injecting equipment.
LDSS are distributed by needle and
syringe programmes and are recommended by the World Health Organization as a
means of reducing the transmission of blood-borne infections. However, evidence
is still lacking on the extent to which LDSS reduce the
transmission of hepatitis C.
Researchers at the University of Bristol and Public Health
England examined data from the United Kingdom Unlinked Anonymous Monitoring
Survey on people who inject drugs to determine if use of LDSS was associated with a lower prevalence of hepatitis C.
The survey recruited people who inject drugs at needle and
syringe programmes and drug treatment services. Participants were asked
questions about their drug-using behaviour and demographics and provided a
dried blood spot sample for HCV antibody testing. All data were anonymised.
The study recruited people who had injected in the previous
month and had an HCV antibody test result.
The survey asked participants to record how many needles
they had used in the past month and how many of these needles were attached to
syringes.
The survey recruited 2174 eligible participants, of whom
55% always used LDSS, 17% used both LDSS
and high dead-space syringes and 27% used only high dead-space syringes.
Exclusive LDSS use varied from 68% of participants in the West Midlands and 66%
in London to 45% in the East Midlands. Exclusive LDSS use was more common in
people who had begun injecting more recently.
Participants had injected on a median of 17 days in the
previous month and 90% had injected heroin. Participants had been injecting for
a median of 15 years and 55% tested positive for HCV antibodies.
People were more likely to report exclusive LDSS use if they
injected heroin compared to other drugs (adjusted odds ratio 1.47, 95% CI
1.04-2.08) and were less likely to report exclusive LDSS use if they injected
into the groin (aOR 0.14, 95% CI 0.11-0.17). The investigators say that the
lower use of LDSS for groin injection is probably related to the need for
larger needles to inject in the groin.
Drug users in the East of England, the East Midlands, the
North-West and Northern Ireland were less likely to report exclusive LDSS use.
The odds of being HCV antibody positive were significantly
lower in exclusive LDSS users (aor 0.77, 95% CI 0.64-0.93) whereas polydrug use
was associated with increased odds of being HCV antibody positive (aOR 1.38,
95% CI 1.25-1.55).
Exclusive LDSS use was especially associated with reduced
odds of being HCV antibody positive in people who had started injecting less
than three years previously (aOR 0.53, 95% CI 0.30-0.95).
The investigators say that although they found an association
between LDSS use and a lower prevalence of HCV, further evidence is needed to
encourage the uptake of LDSS.
They also emphasise the importance of making low dead-space
syringes available that meet the needs of people who are injecting drugs into
the groin, and of developing syringes with detachable needles that have minimal
dead space.