Correlation between wastewater-based substance use prevalence and syringe distribution in a harm reduction program in...

A comprehensive, near-real-time assessment of substance use can offer critical insights to -improve the effectiveness of current harm reduction strategies aimed at preventing overdose fatalities. This study employed wastewater-based epidemiology to monitor psychostimulants, opioids, medications for opioid use disorder, antipsychotics, antidepressants, and cannabis over 12 months in a community operating a syringe services program -. On average, an estimated 44,000 monthly doses of methamphetamine (2660 ± 547 mg/d/1000 people), 41,600 doses of oxycodone (159 ± 109 mg/d/1000 people), 9600 doses of cocaine (688 ± 240 mg/d/1000 people), and 19,000 doses of venlafaxine (242 ± 47.8 mg/d/1000 people) were consumed in an SSP community of approximately 10,000 residents. While monthly syringe distribution showed no correlation with individual drug usage, there was a significant correlation with wastewater-based epidemiology -derived monthly doses of drug classes - such as prescription opioids (R² = 0.737; p = 0.001) and combined doses of psychostimulants and opioids (R² = 0.783; p < 0.001)-indicating that syringes were primarily used for injecting opioids and psychostimulants. This study demonstrates that wastewater-based epidemiology can serve as a potential complementary tool for community-based harm reduction programs by providing accurate data on substance use, evaluating the impact of public health initiatives among people who use drugs, and underscoring the need for new harm reduction initiatives-ultimately aiding in the reduction of overdose fatalities.