TB Screening Recommendations for Workplaces

• TB Screening for Workers in Non-Health Care Settings (child care, shelters, detention)
• Infection Prevention and Control Manual-Shelter/homeless 2022
• Shelter Design and Technical Guidelines, 2023

Employees working in non-health care settings, with the exception of child care centres, shelters and detention facilities, do not have to undergo routine TB screening. If TB screening is required for contact tracing purposes, public health will contact the workplace management and facilitate the screening. 

Employees with a positive TB skin test in contact with someone who has TB

Ensure that employee confidentiality is maintained. It is important to remember that only a person with TB disease can spread the TB germs to others. People who only have a positive skin test are not sick and cannot spread TB germs. Toronto Public Health will follow up with anyone who is a contact of someone with TB disease.

People with TB Infection in the Workplace

A person with TB infection should not be excluded from work. People who have TB infection are not sick and cannot spread TB germs to others.

People with TB Disease in the Workplace

People with TB disease in the lungs or throat can spread the TB germs to other people. Therefore, it may be necessary for them to take time off work until their treatment shows that the TB germ is no longer infectious. Support from the employer is important during this time. Toronto Public Health and the employee’s physician will work closely to determine if the individual can safely report to work.

Role of Toronto Public Health

• A Public Health Nurse (PHN) will help clarify if the employee has TB infection or TB disease by working with the employee’s physician.
• If the employee has infectious TB disease, a PHN will work with their physician to determine when the employee can safely return to work.
• To determine if anyone else may be at risk, a PHN will ask the employee about their job, such as work hours, working conditions and people who work closely with them.
• The PHN may also need to make a site visit to confirm information with management and/or the occupational health department.
• The PHN may also want to speak to people who regularly visit your workplace.
• The PHN will ensure that the person with TB disease receives proper treatment.
• An education session for staff at the workplace can be made available if necessary.
• The PHN will ensure employee confidentiality is maintained throughout the investigation.

Child Care Centres

Interferon Gamma Release Assay – Quantiferon‑ (IGRA QFT)

The Interferon Gamma Release Assay (IGRA), specifically the QuantiferonTB Gold (QFT) test, is a highly sensitive blood test used to determine whether a person has been infected with the tuberculosis (TB) germ, indicating‑ TB infection (latent). Unlike the TB skin test (TST), the IGRA does not cross react with the Bacille ‑CalmetteGuérin‑ (BCG) vaccine and requires only one visit. It is the preferred test for individuals who received one or more BCG vaccinations after the age of one.

In Ontario, the available IGRA test is the Quantiferon‑TB Gold (QFT), which is not currently covered by OHIP. Testing is available through:

• LifeLabs: 1‑877‑849‑3637
• Dynacare: 1‑800‑565‑5721

For full recommendations on IGRA use, refer to the Canadian TB Standards (2022).

Repeat or Annual TB Testing for Staff and Volunteers

Routine annual TB skin testing (TST) or IGRA (QFT) testing is not recommended. Individuals with a previously documented positive TST or IGRA do not require repeat chest X‑rays once TB disease has been ruled out. A new chest X‑ray is only needed if symptoms develop or if there has been a recent exposure to someone with infectious TB disease.

If an infectious TB exposure occurs in a workplace, staff with a previously negative TST or IGRA may require repeat testing. Toronto Public Health coordinates all follow-up for TB exposures. TB testing is provided at no cost for individuals identified as contacts of a person with TB disease.

Early Childhood Education (ECE) Students

Early Childhood Education (ECE) field placements: Confirm with the ECE program that students have complied with the Child Care Centre TB risk assessment prior to starting their placement.

TB Testing for Children

Routine TB testing in children is not recommended.

TB Testing for Individuals Vaccinated with BCG

All staff must undergo a TB risk assessment. If a health care professional determines that testing is needed, they will discuss different options with the staff (e.g., TST or IGRA QFT).

Because the TST may show a false positive result in individuals who received BCG after infancy, the IGRA is preferred for those who received one or more BCG vaccinations after age one. However, a positive TST may still indicate‑ true TB infection, particularly in individuals born in, or who have travelled to, countries with high TB rates.

Chest X‑Ray (CXR) Requirements

Routine repeat annual CXRs are not recommended. A new CXR is only necessary if the individual has symptoms suggestive of TB or has had a recent known exposure to someone with infectious TB disease. See the TB Screening for Workers in Non-Health‑ Care Settings guideline for more details.

Identifying Exposure to Infectious TB

Exposure may be identified in two ways:

• Public health nurses in Canada contact individuals who have been exposed to a person with infectious TB and arrange appropriate follow-up‑ testing (TST or IGRA) and assessment for TB preventive treatment.
• An individual may also learn of an exposure directly from the person diagnosed with TB disease.

Follow-up testing helps determine‑ whether infection has occurred and whether preventive treatment is recommended to reduce the risk of developing TB disease.