NCT04574765

Brief Summary

Recent studies have shown that some individuals may be asymptomatic but continue to shed the COVID-19 virus. These individuals may represent a population that can unknowingly transmit the virus. Healthcare workers (HCW) may acquire COVID-19 from the community or from possibly infected patients. It is important to gather data with respect to this to further understand the prevalence of asymptomatic carriage in individuals who work in research facilities, offices and clinical areas of hospitals and research facilities/institutes since this has important implications for infection control, as well as staff and patient safety. The purpose of this study is to test whether a proportion of these individuals may be asymptomatic shedders of the COVID-19 virus.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
7,373

participants targeted

Target at P75+ for all trials

Timeline
Completed

Started Apr 2020

Shorter than P25 for all trials

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

April 16, 2020

Completed
6 months until next milestone

First Submitted

Initial submission to the registry

September 28, 2020

Completed
7 days until next milestone

First Posted

Study publicly available on registry

October 5, 2020

Completed
4 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 3, 2021

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

February 3, 2021

Completed
Last Updated

July 10, 2025

Status Verified

July 1, 2025

Enrollment Period

10 months

First QC Date

September 28, 2020

Last Update Submit

July 9, 2025

Conditions

Outcome Measures

Primary Outcomes (1)

  • Percentage of healthcare workers who are asymptomatic while COVID-19 positive

    To determine whether asymptomatic individuals who work within a food production, healthcare, research or clinical organizationmay shed CoV during the pandemic. We hypothesize that a small proportion (\~1-10%) of these asymptomatic individuals may be CoV+ either because they are in the incubation period prior to symptoms or remain asymptomatic for the duration of infection.

    2 years

Secondary Outcomes (2)

  • Prevalence of any COVID-19 variants of concern in asymptomatic workers

    2 years

  • Spread of any COVID-19 variants of concern in asymptomatic workers

    2 years

Study Arms (3)

Cohort 1 (A and B)

Cohort 1A included health care workers. Cohort 1B includes individuals that work within a healthcare, research or clinical organization.

Diagnostic Test: Nasopharyngeal swabOther: Questionnaire collection (CITF)Other: Optional blood collectionOther: Optional questionnaire completion (mental health)Diagnostic Test: Optional saliva sample (for validation)Diagnostic Test: Nasal Swab (rapid antigen test)

Cohort 2

Cohort 2 includes Individuals that work within a food production organization.

Diagnostic Test: Nasopharyngeal swabOther: Questionnaire collection (CITF)Other: Optional blood collectionOther: Optional questionnaire completion (mental health)Diagnostic Test: Optional saliva sample (for validation)

Cohort 3

Cohort 3 includes individuals that work within a healthcare, research or clinical organization that will be tested via nasal swab only, with increased frequency of testing.

Diagnostic Test: Nasopharyngeal swabOther: Optional blood collectionOther: Optional questionnaire completion (mental health)Diagnostic Test: Optional saliva sample (for validation)Diagnostic Test: Nasal Swab (rapid antigen test)

Interventions

Nasopharyngeal swabDIAGNOSTIC_TEST

Nasopharyngeal swab for COVID-19

Cohort 1 (A and B)Cohort 2Cohort 3

Fill out questionnaires regarding exposures and travel history, occupation category, any symptoms in the past 21 days, any face-to-face care of a known COVID-19 positive patients in past 14 days or any children at home who are less than 12 years of age.

Also known as: COVID-19 Immunity Task Force (CITF)
Cohort 1 (A and B)Cohort 2

Provide blood samples to look for COVID-19 specific antibodies and/or proteins at the time of enrollment and after 8 weeks.

Cohort 1 (A and B)Cohort 2Cohort 3

Fill out an optional mental health questionnaire.

Cohort 1 (A and B)Cohort 2Cohort 3

Provide saliva sample anonymously.

Cohort 1 (A and B)Cohort 2Cohort 3

Panbio nasal swab rapid antigen test

Cohort 1 (A and B)Cohort 3

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Individuals who work within a food production, healthcare, research or clinical organization.

You may qualify if:

  • Individuals who work within a food production, healthcare, research or clinical organization.
  • Asymptomatic as per daily screening.
  • No contraindication to performing a NP swab.

You may not qualify if:

  • Any individual with fever, respiratory or flu-like symptoms will not be eligible. Symptom positive individuals who were not picked up at entry screening will be referred to their Occupational Health. Specific symptoms include:
  • Fever, chills or headache
  • New or worsening cough
  • Shortness of breath, difficulty breathing, sore throat or difficulty swallowing
  • Runny nose or stuffy nose without another cause (e.g. allergies)
  • Nausea/vomiting, diarrhea, stomach pain
  • Decrease/loss of taste or smell
  • Unexplained fatigue, malaise, muscle aches
  • Eye pain or pink eye In addition to those symptoms listed above, individuals should also be screened for symptoms as per their institutional requirements.
  • Enrolled in a COVID-related interventional study (eg. Behavioural or drug study).

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University Health Network

Toronto, Ontario, M5G 2N2, Canada

Location

Related Links

Biospecimen

Retention: SAMPLES WITHOUT DNA

Nasopharyngeal swabs Optional blood samples

MeSH Terms

Conditions

COVID-19

Interventions

Mental Health

Condition Hierarchy (Ancestors)

Pneumonia, ViralPneumoniaRespiratory Tract InfectionsInfectionsVirus DiseasesCoronavirus InfectionsCoronaviridae InfectionsNidovirales InfectionsRNA Virus InfectionsLung DiseasesRespiratory Tract Diseases

Intervention Hierarchy (Ancestors)

HealthPopulation Characteristics

Study Officials

  • Amit M Oza, MD

    University Health Network, Toronto

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

September 28, 2020

First Posted

October 5, 2020

Study Start

April 16, 2020

Primary Completion

February 3, 2021

Study Completion

February 3, 2021

Last Updated

July 10, 2025

Record last verified: 2025-07

Data Sharing

IPD Sharing
Will not share

Locations