SARS CoV-2 Seroprevalence among First Responders in the District of Columbia, May-July 2020

First responders are at increased risk of occupational exposure to SARS-CoV-2 while providing frontline support to communities during the COVID-19 pandemic. In the District of Columbia (DC), first responders were among the first people exposed to and infected with SARS-CoV-2, with over 200 first responders diagnosed with COVID-19 by May 15, 2020. From June - July 2020, DC Health conducted a serologic survey to estimate SARS-CoV-2 seroprevalence and assess risk factors and occupational exposures among a convenience sample of first responders in DC. Of the 310 first responders tested, 3.5% (n = 11) had anti-SARS-CoV-2 antibodies. Seropositivity varied by occupation, with 4.8% (3/62) of firefighters; 3.6% (8/220) of police officers; and no paramedics (0/10) or administration and support staff (0/18) testing positive. Type and consistency of personal protective equipment (PPE) use also varied: all paramedics (n=10) reported wearing a N95 respirator all or most of the time, compared to 83.3% of firefighters, 38.8% of police officers, and 23.5% of administration and support staff (p<0.001). All paramedics reported wearing gloves all or most of the time, compared to 80.0% of firefighters, 27.8% of administration and support staff, and 24.3% of police (p<0.001). The relatively low seroprevalence among first responders highlights the benefits of continuous training on and reinforcement of the proper use of PPE while performing job duties to mitigate potential transmission within and between first responders and the community. SummaryUnderstanding occupational exposure to and infection with SARS-CoV-2 among first responders is important for workforce planning and emergency preparedness and response. Seroprevalence among first responders (3.5%; 11/310) who participated in a survey conducted by the District of Columbia Department of Health (DC Health) from May 28 - July 15 was 48% lower than reported in the DC community (6.7%; 876/12990). The lower prevalence of SARS-CoV-2 among first responders highlights the importance of continuous training on and reinforcement of the proper use of personal protective equipment (PPE). Proper use of PPE is a critical mitigation strategy to reduce transmission among and between first responders and the community.