Prevalence, Symptoms of Health Care Workers With COVID-19 in Early Phase

Quick Takes

  • Infection with coronavirus was relatively rare (1%) in health care workers prior to their intense involvement in care.
  • The data provide a baseline to assess the incident rate of those working at teaching hospitals over time.
  • The findings support the use of screening persons with exposure rather than limiting sampling to those with symptoms.

Study Questions:

What was the prevalence and clinical presentation of coronavirus disease 2019 (COVID-19) among health care workers (HCWs) with self-reported fever or respiratory symptoms in the very early phase of exposure?


A cross-sectional study was performed in two teaching hospitals in the southern part of the Netherlands in March 2020, during the early phase of the COVID-19 pandemic. HCWs employed in the participating hospitals who experienced fever or respiratory symptoms were asked to voluntarily participate in a screening for infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The prevalence of SARS-CoV-2 infection was determined by polymerase chain reaction on self-collected oropharyngeal samples. Structured interviews were conducted to document symptoms for all HCWs with confirmed COVID-19.


Of 9,705 HCWs employed (18% male), 1,353 (14%) reported fever or respiratory symptoms and were tested. Of those, 86 HCWs (6%) were infected with SARS-CoV-2 (median age, 49 years [range, 22-66 years]; 15 [17%] male), representing 1% of all HCWs employed. Most HCWs experienced mild disease, and only 46 (53%) reported fever. Eighty HCWs (93%) met a case definition of fever and/or coughing and/or shortness of breath. Only three (3%) of the HCWs identified through the screening had a history of travel to China or northern Italy, and three (3%) reported having been exposed to an inpatient with a known diagnosis of COVID-19 before the onset of symptoms.


Within 2 weeks after the first Dutch case was detected, a substantial proportion of HCWs with self-reported fever or respiratory symptoms were infected with SARS-CoV-2, likely as a result of acquisition of the virus in the community during the early phase of local spread. The high prevalence of mild clinical presentations, frequently not including fever, suggests that the currently recommended case definition for suspected COVID-19 should be used less stringently.


Incident COVID-19 was rare in this study of HCWs, at 1%. But samples were self-obtained oral rather than the more sensitive rigorous nasopharyngeal by trained persons. And a significant number of asymptomatic or minimally symptomatic carriers or infected were likely missed, particularly in HCWs who felt compelled to participate in the sudden tragic pandemic.

Clinical Topics: Prevention

Keywords: Cough, COVID-19, Coronavirus, Health Personnel, Fever, Hospitals, Teaching, Inpatients, Polymerase Chain Reaction, Primary Prevention, SARS Virus, Severe Acute Respiratory Syndrome, severe acute respiratory syndrome coronavirus 2, Signs and Symptoms, Respiratory

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