Risk Factors Associated With SARS-CoV-2 Seropositivity Among US Health Care Personnel | Infectious Diseases | JAMA Network Open | JAMA Network
[Skip to Navigation]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
Steensels  D, Oris  E, Coninx  L,  et al.  Hospital-wide SARS-CoV-2 antibody screening in 3056 staff in a tertiary center in Belgium.   JAMA. 2020;324(2):195-197. doi:10.1001/jama.2020.11160PubMedGoogle ScholarCrossref
Iversen  K, Bundgaard  H, Hasselbalch  RB,  et al.  Risk of COVID-19 in health-care workers in Denmark: an observational cohort study.   Lancet Infect Dis. 2020;20(12):1401-1408. doi:10.1016/S1473-3099(20)30589-2PubMedGoogle ScholarCrossref
Jespersen  S, Mikkelsen  S, Greve  T,  et al.  SARS-CoV-2 seroprevalence survey among 17,971 healthcare and administrative personnel at hospitals, pre-hospital services, and specialist practitioners in the Central Denmark Region.   Clin Infect Dis. 2020;ciaa1471. doi:10.1093/cid/ciaa1471PubMedGoogle Scholar
Self  WH, Tenforde  MW, Stubblefield  WB,  et al; CDC COVID-19 Response Team; IVY Network.  Seroprevalence of SARS-CoV-2 among frontline health care personnel in a multistate hospital network—13 academic medical centers, April-June 2020.   MMWR Morb Mortal Wkly Rep. 2020;69(35):1221-1226. doi:10.15585/mmwr.mm6935e2PubMedGoogle ScholarCrossref
Hunter  BR, Dbeibo  L, Weaver  CS,  et al.  Seroprevalence of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) antibodies among healthcare workers with differing levels of coronavirus disease 2019 (COVID-19) patient exposure.   Infect Control Hosp Epidemiol. 2020;41(12):1441-1442. doi:10.1017/ice.2020.390PubMedGoogle ScholarCrossref
Moscola  J, Sembajwe  G, Jarrett  M,  et al; Northwell Health COVID-19 Research Consortium.  Prevalence of SARS-CoV-2 antibodies in health care personnel in the New York City area.   JAMA. 2020;324(9):893-895. doi:10.1001/jama.2020.14765PubMedGoogle ScholarCrossref
Baker  JM, Nelson  KN, Overton  E,  et al.  Quantification of occupational and community risk factors for SARS-CoV-2 seropositivity among healthcare workers in a large U.S. healthcare system.   Ann Intern Med. 2021. doi:10.7326/M20-7145PubMedGoogle Scholar
Muñoz-Price  LS, Nattinger  AB, Rivera  F,  et al.  Racial disparities in incidence and outcomes among patients with COVID-19.   JAMA Netw Open. 2020;3(9):e2021892. doi:10.1001/jamanetworkopen.2020.21892PubMedGoogle Scholar
Scannell Bryan  M, Sun  J, Jagai  J,  et al.  Coronavirus disease 2019 (COVID-19) mortality and neighborhood characteristics in Chicago.   Ann Epidemiol. 2020;S1047-2797(20)30409-9. doi:10.1016/j.annepidem.2020.10.011PubMedGoogle Scholar
US Food and Drug Administration. EUA authorized serology test performance. Published October 14, 2020. Accessed November 10, 2020. https://www.fda.gov/medical-devices/coronavirus-disease-2019-covid-19-emergency-use-authorizations-medical-devices/eua-authorized-serology-test-performance
Suthar  MS, Zimmerman  MG, Kauffman  RC,  et al.  Rapid generation of neutralizing antibody responses in COVID-19 patients.   Cell Rep Med. 2020;1(3):100040. doi:10.1016/j.xcrm.2020.100040PubMedGoogle Scholar
Caturegli  G, Materi  J, Howard  BM, Caturegli  P.  Clinical validity of serum antibodies to SARS-CoV-2 : a case-control study.   Ann Intern Med. 2020;173(8):614-622. doi:10.7326/M20-2889PubMedGoogle ScholarCrossref
Lopman lab. Accessed February 3, 2021. https://github.com/lopmanlab
Bajema  KL, Dahlgren  FS, Lim  TW,  et al.  Comparison of estimated SARS-CoV-2 seroprevalence through commercial laboratory residual sera testing and a community survey.   Clin Infect Dis. 2020;ciaa1804. doi:10.1093/cid/ciaa1804PubMedGoogle Scholar
Hughes  MM, Groenewold  MR, Lessem  SE,  et al.  Update: characteristics of health care personnel with COVID-19—United States, February 12-July 16, 2020.   MMWR Morb Mortal Wkly Rep. 2020;69(38):1364-1368. doi:10.15585/mmwr.mm6938a3PubMedGoogle ScholarCrossref
Kambhampati  AK, O’Halloran  AC, Whitaker  M,  et al; COVID-NET Surveillance Team.  COVID-19-associated hospitalizations among health care personnel—COVID-NET, 13 states, March 1-May 31, 2020.   MMWR Morb Mortal Wkly Rep. 2020;69(43):1576-1583. doi:10.15585/mmwr.mm6943e3PubMedGoogle ScholarCrossref
Boehmer  TK, DeVies  J, Caruso  E,  et al.  Changing age distribution of the COVID-19 pandemic—United States, May-August 2020.   MMWR Morb Mortal Wkly Rep. 2020;69(39):1404-1409. doi:10.15585/mmwr.mm6939e1PubMedGoogle ScholarCrossref
Limit 200 characters
Limit 25 characters
Conflicts of Interest Disclosure

Identify all potential conflicts of interest that might be relevant to your comment.

Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.

Err on the side of full disclosure.

If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.

Not all submitted comments are published. Please see our commenting policy for details.

Limit 140 characters
Limit 3600 characters or approximately 600 words
    1 Comment for this article
    It is Time to Recognize and Address Work-Related Transmission for Health Care Personnel
    Lisa Brosseau, ScD | University of Minnesota
    A cross-sectional study of risk factors for healthcare worker SARS-CoV-2 seropositivity concluded that community rather than workplace exposures are the primary source of COVID-19 infection (1). This conclusion is not supported by a careful examination of the methods and data.

    Identifying the source of an infection requires thorough tracing and interviews of all healthcare and community contacts. This was not done. The authors assumed that workplace infection could only occur for certain job categories or where self-reported. This ignores high rates of pre-and asymptomatic transmission likely for all personnel during regular work activities (2). Conclusions should be made with
    caution about the relationship between exposure and outcome (seropositivity) without a comparison or control group, which this study lacks. Studies of workplace exposure to COVID-19 patients with a comparison group have found higher risk of infection among healthcare personnel (3).

    The investigators fail to note that healthcare personnel had an overall infection incidence rate of 440/10,000 (4.4%), 6 times higher than the average community infection rate of 72.4/10,000 (0.7%) (Table 1). Environmental services personnel had the highest infection incidence rate (7.4%), driven primarily by rates in the Emory and UMD systems. High incidence rates also occurred in patient care technicians, nursing assistants, nurse technicians, nurses, pharmacists and respiratory therapists in one or more of the participating healthcare systems. Differences in incidence by job are unlikely if community transmission plays a larger role than workplace exposure. A study of seroconversion in a UK health system found the highest incidence in housekeepers and those working in general and internal medicine, with risk ratios greater than 2 when compared to intensive care personnel, concluding that differences in seroprevalence rates were more likely due to occupational rather than community factors (4).

    Contrary to the authors’ conclusions, the data indicate that current infection control practices are inadequate at preventing COVID-19 infection at work. All healthcare personnel, including those without direct patient care responsibilities, are at risk of infection. A recent study found SARS-CoV-2 transmission between asymptomatic patients and health care personnel despite the use of medical masks and eye protection (5). It is time to stop pointing fingers at community transmission and recognize and address the importance of work-related exposure.


    1. Jacob JT, Baker JM, Fridkin SK, et al. Risk Factors Associated With SARS-CoV-2 Seropositivity Among US Health Care Personnel. JAMA Netw Open. 2021;4(3):e211283-e211283. doi:10.1001/jamanetworkopen.2021.1283
    2. Oran DP, Topol EJ. The Proportion of SARS-CoV-2 Infections That Are Asymptomatic. Ann Intern Med. Published online January 22, 2021. doi:10.7326/M20-6976
    3. Jespersen S, Mikkelsen S, Greve T, et al. Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence Survey Among 17 971 Healthcare and Administrative Personnel at Hospitals, Prehospital Services, and Specialist Practitioners in the Central Denmark Region. Clin Infect Dis. 2020;(ciaa1471). doi:10.1093/cid/ciaa1471
    4. Shields A, Faustini SE, Perez-Toledo M, et al. SARS-CoV-2 seroprevalence and asymptomatic viral carriage in healthcare workers: a cross-sectional study. Thorax. 2020;75(12):1089. doi:10.1136/thoraxjnl-2020-215414
    5. Klompas M, Baker MA, Griesbach D, et al. Transmission of SARS-CoV-2 from asymptomatic and presymptomatic individuals in healthcare settings despite m
    Original Investigation
    Infectious Diseases
    March 10, 2021

    Risk Factors Associated With SARS-CoV-2 Seropositivity Among US Health Care Personnel

    Author Affiliations
    • 1School of Medicine, Emory University, Atlanta, Georgia
    • 2Rollins School of Public Health, Emory University, Atlanta, Georgia
    • 3University of Maryland School of Medicine, Baltimore
    • 4Rush University Medical Center, Chicago, Illinois
    • 5Johns Hopkins University School of Medicine, Baltimore, Maryland
    • 6US Centers for Disease Control and Prevention, Atlanta, Georgia
    JAMA Netw Open. 2021;4(3):e211283. doi:10.1001/jamanetworkopen.2021.1283
    Key Points

    Question  What risk factors are associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seropositivity among health care personnel (HCP) inside and outside the workplace?

    Findings  In this cross-sectional study of 24 749 HCP in 3 US states, contact with an individual with known coronavirus disease 2019 (COVID-19) exposure outside the workplace was the strongest risk factor associated with SARS-CoV-2 seropositivity, along with living in a zip code with higher COVID-19 incidence. None of the assessed workplace factors were associated with seropositivity.

    Meaning  In this study, most risk factors associated with SARS-CoV-2 infection among HCP were outside the workplace, suggesting that current infection prevention strategies in health care are effective in preventing patient-to-HCP transmission in the workplace.


    Importance  Risks for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among health care personnel (HCP) are unclear.

    Objective  To evaluate the risk factors associated with SARS-CoV-2 seropositivity among HCP with the a priori hypothesis that community exposure but not health care exposure was associated with seropositivity.

    Design, Setting, and Participants  This cross-sectional study was conducted among volunteer HCP at 4 large health care systems in 3 US states. Sites shared deidentified data sets, including previously collected serology results, questionnaire results on community and workplace exposures at the time of serology, and 3-digit residential zip code prefix of HCP. Site-specific responses were mapped to a common metadata set. Residential weekly coronavirus disease 2019 (COVID-19) cumulative incidence was calculated from state-based COVID-19 case and census data.

    Exposures  Model variables included demographic (age, race, sex, ethnicity), community (known COVID-19 contact, COVID-19 cumulative incidence by 3-digit zip code prefix), and health care (workplace, job role, COVID-19 patient contact) factors.

    Main Outcome and Measures  The main outcome was SARS-CoV-2 seropositivity. Risk factors for seropositivity were estimated using a mixed-effects logistic regression model with a random intercept to account for clustering by site.

    Results  Among 24 749 HCP, most were younger than 50 years (17 233 [69.6%]), were women (19 361 [78.2%]), were White individuals (15 157 [61.2%]), and reported workplace contact with patients with COVID-19 (12 413 [50.2%]). Many HCP worked in the inpatient setting (8893 [35.9%]) and were nurses (7830 [31.6%]). Cumulative incidence of COVID-19 per 10 000 in the community up to 1 week prior to serology testing ranged from 8.2 to 275.6; 20 072 HCP (81.1%) reported no COVID-19 contact in the community. Seropositivity was 4.4% (95% CI, 4.1%-4.6%; 1080 HCP) overall. In multivariable analysis, community COVID-19 contact and community COVID-19 cumulative incidence were associated with seropositivity (community contact: adjusted odds ratio [aOR], 3.5; 95% CI, 2.9-4.1; community cumulative incidence: aOR, 1.8; 95% CI, 1.3-2.6). No assessed workplace factors were associated with seropositivity, including nurse job role (aOR, 1.1; 95% CI, 0.9-1.3), working in the emergency department (aOR, 1.0; 95% CI, 0.8-1.3), or workplace contact with patients with COVID-19 (aOR, 1.1; 95% CI, 0.9-1.3).

    Conclusions and Relevance  In this cross-sectional study of US HCP in 3 states, community exposures were associated with seropositivity to SARS-CoV-2, but workplace factors, including workplace role, environment, or contact with patients with known COVID-19, were not. These findings provide reassurance that current infection prevention practices in diverse health care settings are effective in preventing transmission of SARS-CoV-2 from patients to HCP.