Detection of drugs and hepatitis C virus in used syringes from a needle exchange in Gothenburg, Sweden.

People who inject drugs (PWID) are exposed to serious health risks such as lethal overdoses, addiction and infections. The patterns of drug use and the prevalence of hepatitis C virus (HCV) infection vary greatly between and even within countries. Data on drugs used for injection are important to inform PWID of risks and adapt healthcare. This study aimed to determine which substances are injected in Gothenburg, Sweden, and estimate the risk of HCV transmission. A total of 150 syringes handed in at the needle and syringe exchange program (NEP) in Gothenburg over a week in November 2021 were analysed for drug content using liquid chromatography coupled with high-resolution mass spectrometry. Using a dose-adjusted comparison, the main drug(s) injected was distinguished from the impurities in the syringes containing several drugs. HCV RNA was quantified by real-time PCR in an additional set of 150 syringes. Drugs were detected in >99% of analysed syringes, and the most common drugs were amphetamine (81%), followed by buprenorphine (8.0%), heroin (6.7%) and alprazolam (4.6%). Less common findings were testosterone (2.7%), methylphenidate (2.0%), MDMA (0.7%), trenbolone (0.7%) and zopiclone (0.7%). Eleven syringes (7.3%) contained more than one drug. HCV RNA was detected in 13% of the syringes, and one in 10 contained enough to potentially transmit an infection. This study underlines the importance of access to NEPs for PWID to reduce the risks associated with drug injection.