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COVID-19: Contact Tracing

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This document is intended to provide employers and workers with information on how contact tracing is used as a Public Health strategy to reduce COVID-19 transmission.

For general COVID-19 prevention practices for both employers and workers, refer to Protect Yourself and Others from COVID-19.

Control Measures

The most effective way to reduce the risk of COVID-19 transmission is to follow the hierarchy of controls and to use a layered approach. Physical distancing, proper ventilation, good hand hygiene, the wearing of masks, active screening, and contact tracing are some of the preventative measures that can help prevent the spread.

Contact Tracing

Your local Public Health Authority will contact anyone who tests positive for COVID-19 (known as a case) and will work with that person to identify and notify their close contacts as needed. Contact tracing is intended to prevent contacts from getting sick (if possible), help with access to health care if needed, and to reduce the spread of COVID-19 to others.

Contact Tracing Teams

Contact tracing requires time and resources. The teams usually consist of multi-disciplinary health care professional members that assist with tracing and case management especially in communities with high COVID-19 transmission rates.

Steps Involved in Contact Tracing and Case Management

Contact tracing is most effective when done promptly and involves both tracing and case management:

  • Determine when the case was infectious: This period is typically 10 to 14 days from the day a sample was taken for a COVID-19 test or up to 14 days following the onset of symptoms. Check with your local public health authority for guidance on when a person becomes infectious.
  • Identify and list contacts: The team will work with the infected person to identify all the people who had contact with the infected person starting 48 hours before the infected person showed symptoms or had their sample taken for a COVID-19 test. A close contact of a person infected with COVID-19 is someone who:
    • provides care or has close physical contact without appropriate use of personal protective equipment
    • comes into direct contact with infectious body fluids
    • comes within 2 metres of them for a period of 15 cumulative minutes over 24 hours
  • Notify contacts: The contact tracing team will identify individuals that need to be notified based on the duration, proximity, and intensity of the interaction. More rigorous contact tracing is likely to occur in situations where:
    • Exposed individuals (contacts) are at greater risk of disease or outcomes (e.g., older adults, people who are immunocompromised, or those living in a long-term care home)
    • Where it is possible to identify contacts (e.g., employees in a workplace) rather than those who attended a mass gathering that did not use a contact sign-in method (e.g., a concert).
  • Generally, a contact will be notified by telephone to conduct an interview, but the team may email, mail or text depending the situation.
  • Take steps to intervene: The contact tracing team will assess each contact and help as needed, including:
    • Encouraging self-monitoring for symptoms and the use of personal preventive practices to reduce further transmission;
    • Providing support for isolation and quarantine requirements. In some jurisdictions, temporary accommodation is provided;
    • Assisting with access to testing, treatment, and care;
    • Reducing the chance of contacts becoming cases using post-exposure interventions (e.g., medication, vaccination).
  • Gather data: Contact tracing provides information to help make recommendations to existing health and safety measures to reduce the risk of COVID-19 transmission by identifying:
    • Where transmission is happening in the community;
    • The transmission source (e.g., household members, community);
    • What risk factors increase the likelihood of a person getting COVID-19.

How Employers Can Support Contact Tracing Efforts

  • Encourage workers to stay home if they are sick or might be sick.
  • Ask workers to self monitor for symptoms throughout their shift and to report any signs or symptoms immediately. Follow self-assessment steps from the Public Health Agency of Canada or your local public health authority.
  • Encourage the use of the Canada’s COVID-19 Alert App which can alert a person to possible exposures and react appropriately (i.e., isolate at home).
  • Screen your employees, contractors, essential visitors, and customers before they enter your workplace. Use a checklist or questionnaire provided by your local public health authority.
  • Some organizations are using rapid antigen detection tests (RADT) as part of their active screening process. These rapid tests can be useful in detecting people infected with COVID-19, including those who are asymptomatic. Results can be available within 15 minutes to one hour.
  • Determine how you will respond to positive cases and failed screening results, including positive RADT if using. Your local Public Health Authority should be contacted and provide guidance on next steps. They will also contact you if a person was at work and might have been contagious.
  • Employers do not need to close the workplace if an employee tests positive for COVID-19 but should continue to monitor other employees for symptoms.
  • Public Health may not contact the employer if the risk of transmission to other employees was low. Unless otherwise directed, workers can continue to come to work.
  • Workers should continue to work from home whenever possible. Consider flexible or alternate work arrangements.
  • Consider how to support workers who need to self-isolate. A medical note should not be required if the worker has been told to isolate by public health.
  • Employers and workers must work together to identify any accommodation for a safe return to work.
  • Follow the guidance for return to work provided by the worker’s health care provider, local public health authority, and workers compensation board, if applicable.
  • Review and update your return to work policy and procedures to ensure that they comply with Human Rights and relevant Workers Compensation Board legislation.
  • Consider the barriers to contact tracing (e.g., language, stigma) and how they may impact your organization and workers.
  • Provide information in accessible formats and in a language that your workers understand.
  • Individuals may have concerns about the impact on their employment and relationship with their coworkers (e.g., being judged, ignored). Continue to provide resources to all your workers to reduce stigma, and provide mental health support, including your employee assistance plan (EAP) if available.
  • Having recovered from a COVID-19 infection does not guarantee immunity. Workers who have previously tested positive and recovered can still become re-infected. They must adhere to the health and safety measures as required by the local public health authorities and their employer.

Record Keeping

  • Establish a procedure for recording, storing, access, and destruction of screening records. Determine whether documentation will be on paper, by email or combination of both. Records may be required as proof that worker screening is occurring.
  • Information will also be required to support contract tracing. At a minimum ensure that worker, contractor, and essential visitor names and contact information is collected, updated, accurate, and available. Be prepared to identify the location where individuals were working, if possible.
  • COVID-19 test results are sensitive information and must remain confidential. If using RADTs, identify who will have access to the results and how results will be stored.
  • In all cases, ensure your documentation management follows your privacy laws and consult with your local public health authority on requirements for retaining documentation (e.g., up to 30 days) and the method for which documentation should be destroyed.

Continue with your Risk Assessments and Evaluation of Controls

Contact tracing does not replace public or occupational health and safety requirements. Employers must continue to conduct risk assessments to determine how and when COVID-19 can be transmitted in their workplaces. Use the hierarchy of controls to implement solutions using a layered approach to reduce the risk.

Continue with physical distancing, engineering controls, administrative controls, ventilation, cleaning and disinfecting, use of personal protective equipment (PPE) and mask initiatives as part of your health and safety plan. Regularly review your plan and work with your health and safety committee or representative to make changes as needed.

It is important that mental health resources and support are provided to all workers, including access to an employee assistance program, if available.

For further information on COVID-19, refer to the Public Health Agency of Canada.

Note that this guidance is just some of the adjustments organizations can make during a pandemic. Adapt this list by adding your own good practices and policies to meet your organization’s specific needs.
For further information on respiratory infectious diseases, including COVID-19, refer to the Public Health Agency of Canada.

Disclaimer: As public and occupational health and safety information may continue to change, local public health authorities should be consulted for specific, regional guidance. This information is not intended to replace medical advice or legislated health and safety obligations. Although every effort is made to ensure the accuracy, currency, and completeness of the information, CCOHS does not guarantee, warrant, represent or undertake that the information provided is correct, accurate or current. CCOHS is not liable for any loss, claim, or demand arising directly or indirectly from any use or reliance upon the information.

Document last updated March 26, 2021