SARS-CoV-2 is associated with high viral loads in asymptomatic and recently symptomatic healthcare workers.

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  • Additional Information
    • Source:
      Publisher: Public Library of Science Country of Publication: United States NLM ID: 101285081 Publication Model: eCollection Cited Medium: Internet ISSN: 1932-6203 (Electronic) Linking ISSN: 19326203 NLM ISO Abbreviation: PLoS One Subsets: MEDLINE
    • Publication Information:
      Original Publication: San Francisco, CA : Public Library of Science
    • Subject Terms:
      Health Personnel* ; Viral Load*; COVID-19/*diagnosis ; SARS-CoV-2/*isolation & purification; Adult ; Aged ; COVID-19/epidemiology ; COVID-19/transmission ; COVID-19 Nucleic Acid Testing ; Humans ; Infectious Disease Transmission, Patient-to-Professional ; Inpatients ; Middle Aged ; Outpatients
    • Abstract:
      Background: Healthcare workers (HCW) are at increased risk of SARS-CoV-2 infection from both patients and other HCW with coronavirus disease 2019 (COVID-19). RT-PCR cycle threshold (Ct) values of SARS-CoV-2 ≤ 34 and the first 7-9 days of symptoms are associated with enhanced infectivity. We determined Ct values and duration of symptoms of HCW with a positive SARS-CoV-2 test. As HCW often assume their greatest risk of acquiring SARS-CoV-2 is working on a COVID-19 unit, we also determined Ct values and symptom duration of inpatients with a positive SARS-CoV-2 test.
      Methods: From 6/24/2020-8/23/2020, Ct values and duration of symptoms from 13 HCW, 12 outpatients, and 28 inpatients who had a positive nasopharyngeal swab for SARS-CoV-2 were analyzed.
      Results: Among HCW with a positive SARS-CoV-2 test, 46.2% (6/13) were asymptomatic and requested testing due to an exposure to someone with COVID-19; 83.3% (5/6) of those exposures occurred in the community rather than in the hospital. The median Ct value of HCW was 23.2, and 84.6% (11/13) had a Ct value ≤ 34. The median Ct value of 29.0 among outpatients with COVID-19 did not significantly differ from HCW. In contrast, inpatients with a positive SARS-CoV-2 test had a median Ct value of 34.0 (p = 0.003), which translated into a median ~1,000-fold lower viral load than observed in HCW. Among those with symptoms related to COVID-19, no (0/6) HCW compared to 50% (6/12) of inpatients had symptoms for at least one week (p = 0.04).
      Conclusions: At our institution, asymptomatic COVID-19 accounted for nearly half of the cases among HCW. Symptomatic HCW had high viral loads and short duration of symptoms, both of which are associated with peak infectivity. Infection prevention programs should educate HCW on these findings in an effort to increase adherence to the requirement to maintain six feet separation in workspaces and breakrooms, in addition to consistently wearing personal protection equipment.
      Competing Interests: Dr. Clancy has been awarded investigator-initiated research grants from Astellas, Merck, Melinta, and Cidara for studies unrelated to this project, served on advisory boards or consulted for Astellas, Merck, the Medicines Company, Cidara, Scynexis, Shionogi, Qpex and Needham & Company, and spoken at symposia sponsored by Merck and T2Biosystems. The other authors report no conflicts. This does not alter our adherence to PLOS ONE policies on sharing data and materials.
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    • Publication Date:
      Date Created: 20210318 Date Completed: 20210405 Latest Revision: 20210405
    • Publication Date:
      20240105
    • Accession Number:
      PMC7971491
    • Accession Number:
      10.1371/journal.pone.0248347
    • Accession Number:
      33735264