LAUSR

BACKGROUND AND AIMS Opioids biosurveillance is a new approach to public health surveillance of non-fatal overdoses that relies on laboratory analysis of residual biospecimens from hospitals treating opioids overdoses. In Rhode Island, USA, hospitals report suspected opioid overdoses to the Department of Health. Residual specimens associated with these overdoses are submitted to the State Health Laboratories for further characterization. This surveillance project aimed to characterize non-fatal overdoses through toxicological testing of urine specimens associated with non-fatal overdoses during the initial 2 year period of biosurveillance implementation in Rhode Island to assess the feasibility and public health utility of this approach. METHODS This study included individuals who presented for treatment for a suspected opioid overdose in 10 Rhode Island hospitals between July 2019 and June 2021. Urine samples were received for 1354 unique overdose encounters corresponding to reported overdoses. Some individuals experienced multiple overdoses during this time. Urine samples were extracted and then analyzed by liquid chromatography tandem mass spectrometry with a panel consisting of 40 opiates, synthetic opioids, fentanyl analogs, and select metabolites. Temporal and spatial trends were evaluated for the studied population. RESULTS 1,354 samples were tested for the presence of opioids in urine collected from individuals who experienced a suspected overdose. Fentanyl (and/or norfentanyl) was present in 79% of all samples in which opioids were found (n = 1,033). Fentanyl analogs varied in their contribution to these totals; with observations ranging as high as 35% of all opioid-containing samples in August 2019 and May 2021. CONCLUSIONS Laboratory identification of opioids involved in suspected overdoses shows that fentanyl and its analogs are the main drivers of the opioids overdose epidemic in Rhode Island, USA. The biosurveillance approach is unique in its ability to quantify contributions of novel fentanyl analogs to the burden of overdoses.