Symptom Screening at Illness Onset of Health Care Personnel With SARS-CoV-2 Infection in King County, Washington

As the coronavirus disease 2019 (COVID-19) pandemic continues, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposures among US health care personnel (HCP) during health care delivery and from community contacts will increase. Results from real-time reverse transcriptase–polymerase chain reaction suggest that high viral loads may be detected soon after illness onset, including in minimally symptomatic persons.¹ Current COVID-19 HCP screening guidance² includes assessing fever and respiratory symptoms (cough, shortness of breath, or sore throat) with clinical discretion for evaluation for other symptoms (eg, myalgias). We assessed the spectrum of symptoms at onset of COVID-19 among HCP and evaluated current screening criteria for identifying COVID-19 cases early in illness course.

All laboratory-confirmed SARS-CoV-2 infections in HCP residing in King County, Washington, beginning February 28, 2020, the date the first confirmed case was recognized in a King County long-term care facility,³ through March 13, 2020, were included. HCP were tested after meeting their facilities’ signs and symptoms criteria for testing, which varied. We conducted telephone interviews soliciting the following: demographics, chronic medical conditions (eg, obesity, hypertension, diabetes, and hepatic, cardiac, and pulmonary disease), nature of patient care, occupation and work location, symptom history, days worked while symptomatic, and clinical outcome. Symptoms at illness onset included all those reported for the calendar day during which the HCP first felt unwell. Data collection was conducted as part of a public health response and was deemed by the Centers for Disease Control and Prevention to be exempt from review by an institutional review board.

Fifty of the HCP were identified through March 13, 2020; we interviewed 48. The median age was 43 years (range, 22-79 years); 37 (77.1%) were female. Most of the HCP (37 [77.1%]) performed direct patient care; the remainder included administrative assistants, environmental service workers, and maintenance workers. Twenty-three of the HCP (47.9%) had chronic medical conditions. The HCP worked in 22 health care settings including long-term care facilities (24 [50.0%]), outpatient clinics (13 [27.1%]), and acute care hospitals (6 [12.5%]). Three of the HCP concurrently worked at more than 1 health care facility.

The most common initial symptoms were cough (24 [50.0%]), fever (20 [41.7%]), and myalgias (17 [35.4%]) (Table). Eight of the HCP (16.7%) did not report fever, cough, shortness of breath, or sore throat at symptom onset; among this group, the most common symptoms were chills, myalgia, coryza, and malaise. One of the HCP did not have fever, cough, shortness of breath, or sore throat at any time during illness and only reported coryza and headache. For the other 7 HCP, the median time from illness onset to symptoms currently used to screen for COVID-19 was 2 days (range, 1-7 days). If myalgias and chills are included in screening criteria at illness onset, case detection among HCP increased from 40 (83.3%) to 43 cases (89.6%) (Figure). Among those interviewed, 31 (64.6%) reported working a median of 2 days (range, 1-10 days) while exhibiting any symptoms.

In this cohort, screening only for fever, cough, shortness of breath, or sore throat might have missed 17% of symptomatic HCP at the time of illness onset; expanding criteria for symptoms screening to include myalgias and chills may still have missed 10%. The data indicate that HCP worked for several days while symptomatic, when, according to a growing body of evidence, they may transmit SARS-CoV-2 to vulnerable patients and other HCP.¹ Interventions to prevent transmission from HCP include expanding symptoms-based screening criteria,² furloughing symptomatic HCP,² facilitating testing of symptomatic HCP,⁴ and creating sick leave policies that are nonpunitive, flexible, and consistent with public health guidance.⁵ Face mask use by all HCP for source control might prevent transmission from mildly symptomatic and asymptomatic HCP. This may be particularly important in long-term care facility settings and regions with widespread community transmission.^5,6

Limitations to this study included small sample size, short study time frame, variability in each facility’s testing criteria for HCP, and limited testing availability at the time of this investigation. Because this study was centered on testing based on symptoms, those with atypical and absent symptoms may be underestimated.

Corresponding Author: Eric J. Chow, MD, MS, MPH, Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, H24-7, Atlanta, GA 30329 (echow@cdc.gov).

Published Online: April 17, 2020. doi:10.1001/jama.2020.6637

Author Contributions: Dr Chow had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Chow, Schwartz, Zacks, Reddy, Rao.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Chow, Tobolowsky, Reddy, Rao.

Critical revision of the manuscript for important intellectual content: Chow, Schwartz, Zacks, Huntington-Frazier, Reddy, Rao.

Administrative, technical, or material support: Zacks, Huntington-Frazier, Reddy.

Supervision: Reddy, Rao.

Conflict of Interest Disclosures: None reported.

Funding/Support: The case investigations, analysis, and manuscript preparation were completed as part of official duties at the Centers for Disease Control and Prevention (CDC).

Role of the Funder/Sponsor: The CDC designed and conducted this study; received, managed, analyzed, and interpreted the data; prepared, reviewed, and approved the manuscript; and had a role in the decision to submit the manuscript for publication.

Disclaimer: The findings and conclusion in this report are those of the authors and do not necessarily represent the official position of the CDC.

Additional Contributions: We thank Temet M. McMichael, PhD, Claire Brostrom-Smith, MSN, Vance Kawakami, DVM, David Baure, RN, Eileen Benoliel, RN (Public Health–Seattle and King County), Hammad Ali, PhD, Dustin W. Currie, PhD, Jonathan Dyal, MD, Michael J. Hughes, MPH, and Lisa Oakley, PhD (CDC), for assisting with data collection and Meagan Kay, DVM, James Lewis, MD, Jeffrey S. Duchin, MD (Public Health–Seattle and King County), John Jernigan, MD, Margaret A. Honein, PhD, and Thomas A. Clark, MD (CDC), for providing critical feedback on the manuscript. None of these individuals received compensation for their contributions to this study.