Dead space in over-the-counter syringes: The implications for HIV and HCV transmission

Abstract

BACKGROUND: High dead space syringes (HDSS), compared to low dead space syringes (LDSS), are linked to injection-related HIV and hepatitis C transmission among people who inject drugs (PWID). Syringes are sold over-the-counter to PWID; however, little is known regarding syringe dead space in community pharmacies. This study measured the volume of syringe dead space, quantified available HDSS, and compared the average cost of LDSS vs. HDSS. METHODS: Pharmacies in three cities were selected. Two of each available syringe product were purchased from each of the three pharmacies and were categorized as insulin, tuberculin, or 'other.' The International Standard 8537 method was used to quantify dead space and HDSS vs. LDSS determination was based on syringe design. RESULTS: 43% of the 40 syringe products were HDSS. Among HDSS, dead space capacity ranged from 4.00% to 5.90% in insulin syringes, 5.60% to 6.60% in tuberculin syringes, and 0.82% to 6.40% in 'other' syringes. Among LDSS, dead space capacity ranged from 0.00% to 1.33% in insulin syringes and 0.13% to 4.90% in 'other' syringes. Mean (+/-S.D.) syringe cost was $0.34 (+/-$0.03) for HDSS and $0.35 (+/-$0.06) for LDSS. CONCLUSIONS: Given the high proportion of HDSS, efforts are needed to promote LDSS in pharmacies to help reduce disease transmission among PWID who share syringes