Prevalence of SARS-CoV-2 Antibodies in First Responders and Public Safety Personnel

New York City, New York, USA, May-July 2020

Samira Sami; Lara J. Akinbami; Lyle R. Petersen; Addie Crawley; Susan L. Lukacs; Don Weiss; Rebecca A. Henseler; Nga Vuong; Lisa Mackey; Anita Patel; Lisa A. Grohskopf; Beth Maldin Morgenthau; Demetre Daskalakis; Preeti Pathela


Emerging Infectious Diseases. 2021;27(3):796-804. 

In This Article


A total of 5,091 (22.5% [95% CI 21.9%–23.0%]) participants tested positive for SARS-CoV-2 IgG (Table); however, only 10.1% (95% CI 9.8%–10.5%]) of participants reported previous positive results for SARS-CoV-2 by reverse transcription PCR. Seroprevalence was higher among women than men, higher among non-Hispanic Black persons than other racial or ethnic groups, higher among persons 18–24 years of age compared with older age groups, and higher among persons who were severely obese compared with those with a lower weight status (Table). Seropositivity was highest among those with exposure to a household member who tested positive for SARS-CoV-2 (48.3% [95% CI 46.3%–50.3%]). In addition, seropositivity was highest among persons who resided in the Bronx (28.8% [95% CI 26.8%–30.9%]) and lowest among those residing outside of NYC (18.3% [95% CI 17.5%–19.2%]). Participants who lived in multiunit housing had higher seropositivity than those who lived in single-family housing, as did participants in very large households (≥8 persons) compared with households of ≤7 persons (Appendix Figure 2).

Figure 2.

Unadjusted percentage of respondents who were seropositive for severe acute respiratory syndrome coronavirus 2 IgG, by aerosol-generating procedure frequency (A) and use of personal protective equipment (B), in a study of first responders and public safety personnel, New York City, New York, USA, May 18–July 2, 2020. Numbers within bars indicate percentage of seropositive respondents. Error bars indicate 95% CIs. First responders and public safety personnel include police, medicolegal death investigators, firefighters, correctional staff, security guards, traffic officers, police dispatchers, firefighters or medical first responders, paramedics, emergency medical technicians, dispatchers (emergency medical service or fire), and other direct patient-care providers. COVID-19, coronavirus disease.

Seroprevalence was higher among those who worked in correctional facilities (36.2% [95% CI 33.6%–39.0%]) and EMS agencies (35.2% [95% CI 33.3%–37.2%]) compared with those who worked in other workplaces (range 11.7%–21.3%) (Table). Seroprevalence also varied by occupation (Figure 1). We also observed differences in seroprevalence by workplace borough; prevalence was highest in the Bronx (26.8%) and lowest in Staten Island (17.4%) (Table).

The remainder of the analysis focused on first responders and public safety personnel (n = 19,909).[3–6] Seropositivity increased with increasing frequency of aerosol-generating procedures performed per shift (p = 0.002), ranging from 20.7% among persons who did not conduct these procedures to 31.6% among those who conducted procedures >25 times on average per shift (Figure 2). Seropositivity also varied by frequency of PPE use when within 6 feet of a person with confirmed or suspected COVID-19, including stratification by occupation (Figure 2; Appendix Figure 3). Overall, for each PPE component, those who reported use all of the time had a significantly higher percent positivity than those who reported not all of the time (p<0.05).

Figure 3.

Adjusted odds ratios of seropositivity for severe acute respiratory syndrome coronavirus 2 IgG in a study of first responders and public safety personnel, New York City, New York, USA, May 18–July 2, 2020. Adjusted model includes all variables shown. Black boxes indicate statistically significant results; error bars indicate 95% CIs. Participants of other racial or ethnic groups or who declined to provide their race or ethnicity are included in the models but not shown as separate categories. Variables for exposure to person with COVID-19 are not mutually exclusive. AGP, aerosol-generating procedure; COVID-19, coronavirus disease; EMS, emergency medical service; ref, referent; PAPR, powered air-purifying respirator; PPE, personal protective equipment.

In adjusted analyses, women and those exposed to a patient with suspected or confirmed COVID-19 were less likely to be seropositive than their counterparts (Figure 3; Appendix Table 2). Characteristics associated with increased odds of seropositivity were self-reported exposure to a household member who tested positive for SARS-CoV-2, non-Hispanic Black versus non-Hispanic White race or ethnicity, severe obesity versus underweight or normal weight status, and residing or working in Brooklyn versus Staten Island. Correctional staff, EMTs, traffic officers, paramedics, security guards, dispatchers (EMS or fire and police), and firefighters were more likely than police to be seropositive; correctional staff had the highest likelihood of seropositivity (adjusted odds ratio [aOR] 2.55 [95% CI 2.18–2.99]). The aOR for seropositivity when using any PPE component all of the time was not significant. However, workers who reported using gloves all of the time were significantly more likely than those who used gloves not all of the time to be seropositive (aOR 1.19 [95% CI 1.06–1.33]).