Tuberculosis Skin Testing & Interferon Gamma Release Assay Testing

Updated: January 2020

Both the Tuberculosis Skin Test (TST) and Interferon Gamma Release Assay (IGRA) are acceptable tests for Latent Tuberculosis Infection (LTBI) diagnosis.

TST

The TST determines if someone has developed a cell-mediated immune response to the Tuberculosis (TB) bacterium – it does not detect the presence of TB bacteria directly. This immune response occurs if someone has been exposed to TB in the past.

More information

Latent TB Infection – Diagnosis, Treatment and Reporting

Billing: Ontario Health Insurance Program (OHIP) insured

If a Public Health Department requests a TB skin test, then both the test and completion of the form/report cannot be billed to the patient. Medically necessary TB skin tests and documentation are covered under OHIP. Only the appropriate OHIP fees can be claimed. (e.g., A001 for the visit/assessment and G372 for the injection).

 These include testing for:

  • people who are identified by a public health department as contacts of infectious active TB disease
  • people who have recently immigrated from countries where TB is more common

TB skin tests and documentation are also covered under OHIP for:

  • people who require evidence of a completed TB skin test for admission or continuation in a daycare or pre-school program or a school, community college, university or other educational institution or program (including a work placement that the program may require)
  • people who are 65 years of age or younger who need to be admitted to a Long Term Care Facility

Billing: Non-insured

TB skin testing solely for employment/volunteer purposes are not OHIP-insured and can be billed to the patient or third party.

Government provided tubersol (TST solution) for uninsured TB testing

Please note that tubersol provided by the government is not to be used for uninsured TB testing. When uninsured testing is performed, the tubersol should be either:

  • acquired by the physician and sold to the patient at a direct cost (with reasonable mark-up to account for any indirect costs (e.g., storage, administrative, etc.), or
  • acquired by the patient from the pharmacy, via prescription provided by the physician

Resources

The IGRA blood test screens for exposure to Tuberculosis (TB) by indirectly measuring the body’s immune response to antigens derived from the TB bacteria. The IGRA test can differentiate a Bacille Calmette-Guerin (BCG) response from a TB exposure-response.