Spatiotemporal Trends in Discarded Needle Reports in San Francisco Over a 10-year Period, 2010-2019.

BACKGROUND: To describe the geographic and spatiotemporal distribution of needle reports in San Francisco, and examine spatial relationships between needle reports and needle disposal boxes, needle disposal kiosks, and homeless shelters.
METHODS: We conducted multiple geospatial analyses of a crowdsourced database of non-emergency service requests. We describe changes in discarded needle and bulky item reports across San Francisco between 2010 and 2019, and compared changes in the reporting patterns of these items, while 200-meter Euclidean buffers captured needle reports in close proximity to needle deposit boxes, needle deposit kiosks, and homeless shelters in 2019.
RESULTS: 34,912 needle reports were included. Yearly needle reports increased by 3827.1%, with a markedly different geospatial distribution from bulky item reports. 45.6% of needle reports originated in the five downtown neighborhoods with the highest needle report density, and 33.8% were identified within 200 meters of boxes, kiosks, or homeless shelters.
CONCLUSIONS: Reports of discarded needles in San Francisco increased dramatically over the last decade, and more than one third of 2019 reports were adjacent to harm reduction and homeless shelter locations. Needle reports provide an opportunity to understand changes in public injection drug use and target harm reduction services.