Large-Scale Testing of Asymptomatic Healthcare Personnel for Severe Acute Respiratory Syndrome Coronavirus 2

Catherine A. Hogan; Saurabh Gombar; Hannah Wang; Katharina Röltgen; Run-Zhang Shi; Marisa Holubar; Sang-ick Chang; Grace M. Lee; Scott D. Boyd; James Zehnder; Benjamin A. Pinsky


Emerging Infectious Diseases. 2021;27(1):250-254. 

In This Article

Abstract and Introduction


Large-scale, 1-time testing of >12,000 asymptomatic healthcare personnel in California, USA, during April–June 2020 showed that prevalence of severe acute respiratory syndrome coronavirus 2 was low (<1%). Testing might identify asymptomatic and presymptomatic persons, including some with high viral burden, enabling prompt implementation of measures to limit nosocomial spread.


Healthcare personnel (HCP) represent a unique group of concern for transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19), because of their increased exposure risk from infected patients under their care and risk for onward transmission to patients and coworkers. The current evidence on the large-scale testing of HCP has focused on symptomatic persons.[1] However, the potential for asymptomatic transmission of SARS-CoV-2 is well-recognized,[2–4] and presymptomatic HCP might contribute to nosocomial outbreaks.[5]

Testing HCP before symptom onset represents an opportunity for early detection of infectious persons. In this study, we assessed the prevalence of SARS-CoV-2 infection through mass real-time reverse transcription PCR (rRT-PCR) and IgG testing of asymptomatic HCP and describe the clinical and laboratory characteristics of infected persons.