Low dead-space syringes associated with lower hepatitis C prevalence in people who inject drugs

Keith Alcorn
Published:
01 October 2018

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.

Reference

Trickey A et al. Usage of low dead space syringes and association with hepatitis C prevalence amongst people who inject drugs in the UK. Drug and Alcohol Dependence, advance online publication, September 2018.