Background: Rigorous assessment of occupational COVID-19 risk and personal protective equipment (PPE) use are not well-described. We evaluated 9-1-1 emergency medical services (EMS) encounters for patients with COVID-19 to assess occupational exposure, programmatic strategies to reduce exposure, and PPE use.
Methods: We conducted a retrospective cohort investigation of lab-confirmed COVID-19 patients in King County, WA who received 9-1-1 EMS responses from February 14, 2020 to March 26, 2020. We reviewed dispatch, EMS, and public health surveillance records to evaluate the temporal relationship between exposure and programmatic changes to EMS operations designed to identify high-risk patients, protect the workforce, and conserve PPE.
Results: There were 274 EMS encounters for 220 unique COVID-19 patients involving 700 unique EMS providers with 988 EMS person-encounters. Use of full PPE including mask, eye protection, gown and gloves (MEGG) was 67%. There were 151 person-exposures among 129 individuals, who required 981 quarantine days. Of the 700 EMS providers, 3 (0.4%) tested positive within 14 days of encounter. Programmatic changes were associated with a temporal reduction in exposures. When stratified at the study encounters midpoint, 94% (142/151) of exposures occurred during the first 137 EMS encounters compared to 6% (9/151) during the second 137 EMS encounters (p<0.01). By the final week of the study period, EMS deployed MEGG PPE in 34% (3579/10,468) of all EMS person-encounters.
Conclusion: Less than 0.5% of EMS providers experienced COVID-19 illness within 14 days of occupational encounter. Programmatic strategies were associated with a reduction in exposures, while achieving a measured use of PPE.