What is the evidence behind symptomatic/asymptomatic healthcare worker testing at remote sites? 

Posted on April 28, 2020 by Kristin Walters

Summary

The latest evidence supports routine testing of healthcare workers where possible in order to reduce workforce burden and the spread of COVID-19 in healthcare settings (7).   Current testing limitations do not yet allow for wide scale screening of healthcare workers, and below is a summary of the provincial and national guidelines for testing criteria in Canada. 

I.   HCW TESTING EVIDENCE

  •   Increasing evidence suggests that SARS-CoV-2 can be transmitted by persons who are asymptomatic, pre-symptomatic, or pauci-symptomatic (2.5 days prior to symptom onset). RT-PCR levels have been found to be high early in infection (8).
  •   The argument in support of testing asymptomatic HCW’s follows the evidence that there are 1) a number of workers unnecessarily self-isolating and depleting the workforce, and 2) asymptomatic (pre-symptomatic) HCW’s are an underappreciated potential source of infection worthy of testing (7).
  • An NHS hospital in London will commence testing expansion to include asymptomatic HCW’s (symptomatic are prioritized) with the intent of limiting nosocomial transmission, and to reduce anxiety for HCW’s (7)

II.   PROVINCIAL HCW TESTING CRITERIA

 

British Columbia (1) No symptoms

 

 

No test required
Mild respiratory symptoms – self assessment tool No test required

 

LTC workers – test required

Fever ≥ 38°C Test recommended
Fever ≥ 38°C or new onset/exacerbation of cough/shortness of breath Test recommended
Where to get a test Call 811 to find the nearest test centre
Alberta (2) No symptoms No test required
Symptoms Complete the online self-assessment tool to determine if a test is indicated.
Ottawa (3) No symptoms No test Required
Symptomatic HCW (typical/atypical) Test recommended
Saskatchewan (4) No symptoms No test required
Any symptoms Test recommended (preferably within < 48 hours of symptom onset)

 

HCW testing is prioritized

Ontario Ministry of Health (5) Symptomatic

·   Fever ≥ 38.8°C

·   New or worsening respiratory symptoms

·   Clinical/radiological evidence of pneumonia

Test recommended

III.   NATIONAL RECOMMENDATIONS

 

Health Canada List of HC approved lab-based and point of care testing diagnostic tests Can be found here

IV.   SPECIFIC TESTING ACCOMMODATION OF REMOTE HCW’S IN CANADA

  • At this time, there does not appear to be any evidence to specifically address rural testing of HCW’s with the exception of the rolling out of additional point of care testing devices.
  • PHAC and the NRC have issued a challenge for applicants to provide non-traditional point of care molecular diagnostic solutions to detect COVID-19 from sources other than a nasopharyngeal swab with a rapid single-use home testing kit (9).
  • There are currently 15 COVID-19 diagnostic tests approved by Health Canada and a further 21 tests are under expedited review (10).
  • Provinces are being prioritized to receive the new Spartan Cube COVID-19 nucleic acid technology to allow for remote and increased levels of testing at the point of care.

Questions? Comments? Does this need to be updated? Do you have valuable points to add ? Please email ask.reakt@ubc.ca.

References

  1. BC Centre for Disease Control.  Testing and case management for healthcare workers. 2020. [Online]  http://www.bccdc.ca/health-professionals/clinical-resources/covid-19-care
  2. Alberta Health Services. Novel Coronavirus (COVID-19) FAQ – Staff. April 28, 2020. [Online] https://www.albertahealthservices.ca/assets/info/ppih/if-ppih-ncov-2019-staff-faq.pdf
  3. Ottawa Public Health. Information on COVID-19 for Physicians and Healthcare Professionals. April 28, 2020. [Online] https://www.ottawapublichealth.ca/en/professionals-and-partners/hcp-ncov.aspx#Management-of-Health-Care-Workers–

Accessed On: April 30, 2020

  1. Saskatchewan Health Authority. Clinical Guidelines for Testing, Management, and Reporting. April 3, 2020. [Online] https://www.saskatchewan.ca/government/health-care-administration-and-provider-resources/treatment-procedures-and-guidelines/emerging-public-health-issues/2019-novel-coronavirus/information-for-health-care-providers/testing-screening-treatment-and-medical-directives/clinical-guidelines#testing-criteria

Accessed On: April 30, 2020

  1. Ontario Mistry of Health. COVID-19 Provincial Testing Guidance Update. April 8, 2020. [Online] https://www.corhealthontario.ca/COVID-19-Testing-Guidance-Update-(2020-04-08).pdf

Accessed On: April 30, 2020

  1. Chow, E.J., Schwartz, N.G., Tobolowsky, F.A., et al., Symptom Screening at Illness Onset in Care Personnel with SARS-CoV-2 Infection in King County, Washington. JAMA. April 1, 2020. [Online] https://jamanetwork.com/journals/jama/fullarticle/2764953

Accessed On: April 30, 2020

  1. Black, J.R.M., Przewrocka, J., Dijkstra, K.K., Swanton, C., COVID-19: The Case for Healthcare Worker Screening to Prevent Hospital Transmission. The Lancet. April 16, 2020. [Online] https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30917-X/fulltext

Accessed On: April 30, 2020

  1. AHS Scientific Advisory Group Rapid Response Report. What is the Evidence Supporting the Possibility of Asymptomatic Transmission of SARS-CoV-2? April 13, 2020. [Online] https://www.albertahealthservices.ca/assets/info/ppih/if-ppih-covid-19-rapid-response-asymptomatic-transmission.pdf

Accessed On: April 30, 2020

  1. Government of Canada. COVID-19 Challenge – Point of Care and Home Diagnostic Kit for COVID-19. April 5, 2020. [Online] https://www.ic.gc.ca/eic/site/101.nsf/eng/00100.html

Accessed On: April 30, 2020

  1. Health Canada. COVID-19 Diagnostic Device Applications Approved and Under Review. [Online] https://www.canada.ca/en/health-canada/services/drugs-health-products/medical-devices/covid-19/diagnostic-devices-authorized.html

Accessed On: April 30, 2020

Disclaimer

The above is intended to serve as a rapidly-created, accessible source of information curated by medical students and healthcare professionals. It is for educational purposes only and is not a complete reference resource. It is not professional medical advice, and is not a substitute for the discretion, judgment, and duties of healthcare professionals. You are solely responsible for evaluating the information above.