Two-Step Tuberculin Skin Tests

Policy

Category: Control of Infectious Diseases
Subject: Two-Step Tuberculin Skin Tests
Division: Health Protection
Policy Number: CA.82.01.204
Effective Date: February 26, 2016

POLICY STATEMENT

Sub-headings, if neededWellington-Dufferin-Guelph Public Health (WDGPH) will offer two-step tuberculin skin testing (TST) to establish an accurate baseline for individuals with a history of exposure to tuberculosis (TB), contact tracing or anyone requiring testing where it is important to differentiate between a booster effect and conversion.

SCOPE

This policy applies to all WDGPH Public Health Nurses (PHNs) and nursing students who are required to administer a two-step TST within the scope of this program.

DEFINITIONS

Two-step TB Test – The administration of two tuberculin skin tests is ideally done with one to four weeks between steps. The second step may be planted at any time from one week to one year later as long as there has been no risk of exposure to active disease between the first and second steps. When the second step is planted more than four weeks after the first step the validity of the second step as a booster versus a conversion must be assessed on a case by case basis (ruling out exposure to active disease).

REFERENCES AND RELATED FORMS, POLICIES AND PROCEDURES

Corresponding Procedure:  CA.82.02.204 Two-Step Tuberculin Skin Tests
Health Protection and Promotion Act, 1990
Ontario Public Health Standards, 2008
Infectious Diseases Protocol, 2009
Tuberculosis Prevention and Control Protocol, 2008 or as is current
Canadian Tuberculosis Standards (online as current)
Product Monograph: Tubersol ®; Tuberculin Purified Protein Derivative (Mantoux)

CONTACT FOR INQUIRIES

Manager, Control of Infectious Diseases

APPROVED BY

Director, Health Protection 


Procedure

Category: Control of Infectious Diseases
Subject: Two-Step Tuberculin Skin Tests
Division: Health Protection
Procedure Number: CA.82.02.204
Effective Date: February 26, 2016

PROCEDURE

1. Two-step skin testing is indicated to establish an accurate baseline for anyone with a past history of exposure to tuberculosis (TB).  Those individuals who fall into a high-risk group are as follows:

  • Immigrants from endemic countries;
  • Anyone with a history of BCG but negative on first TST; and
  • People commencing serial testing programs such as in hospitals, long-term care facilities, correctional facilities, homeless shelters, and drop-in centres.

2. The two-step skin test requires the administration of two tuberculin tests. Refer to Medical Directive CA.40.01.111 Tuberculin Skin Testing TST and procedure CA.40.02.112 Tuberculin Purified Protein Derivative Mantoux (Tubersol).  The Public Health Nurse (PHN) will complete the TB Skin Test Consent Form (HPDTB(F)20), the TB Skin Test Consent form for the Workplace (HPDTB(F)28), or the TB Skin Test Consent Form for Stonehenge (HPDTB(F)29).  To obtain informed consent, the PHN may provide the client with the fact sheet 2-step Tuberculosis (TB) Skin Test (HPDTB(FS)3) or the fact sheet Tuberculosis or TB Skin Test (HPDTB(FS)4).

3. The client will be advised to have Wellington-Dufferin-Guelph Public Health (WDGPH) read the TST within 48 to 72 hours. The PHN will measure the transverse diameter (to the long axis of the forearm) of any indurations (not redness) and record in mm. Any blistering or more severe reaction should be documented.

4. If the reaction to the first test is positive, the test is complete. Record results in mm and follow-up according to CA.82.01/02.205 Follow-Up Positive Tuberculin Skin Test.

5. If the reaction to the first test is 0-9 mm, a second skin test is given in the opposite forearm one to four weeks later.  A negative reaction to the second test indicates the person is most likely not infected, while a positive reaction to the second test represents a boosted reaction.

6. If the reaction to the second test is positive, the PHN will notify the family physician by telephone and/or fax of positive results. The PHN will advise the physician that this is the second step of a two-step test and recommend that the physician complete a chest x-ray on the client. The PHN will complete and fax the Positive Tuberculin (TB) Skin Test reporting form (CHDPTB(F)5) to the family physician.  If the client does not have a family physician, refer to Step 3 as outlined in the procedure CA.82.02.205 Follow-up of Positive Tuberculin Skin Test.

7. The PHN will complete a Tuberculosis Test Certificate (HPDTB(F)21) and provide this to the client as a record of test.

8. The PHN will submit required information via iPHIS to the Ministry of Health and Long-Term Care.

RESPONSIBILITIES

Management will:
  • Ensure employees adhere to this policy and procedure;
  • Ensure new employees are trained to plant and interpret TSTs; and
  • Monitor policy compliance on a regular basis.
Employees will:
  • Adhere to this policy and procedure;
  • Obtain informed consent from the client;
  • Read and interpret results of TST within 48 to 72 hours after administration;
  • Record results as outlined in procedure;
  • Report any positive results as outlined in procedure CA.82.02.205 Follow-up of Positive Tuberculin Skin Test; and
  • Ensure all individuals with positive TST results are referred for further medical follow-up.

REFERENCES AND RELATED FORMS, POLICIES AND PROCEDURES

Corresponding Policy CA.82.01.204 Two-Step Tuberculin Skin Tests
CA.82.01.205 and CA.82.02.205  Follow-up Positive Tuberculin Skin Test.
CA. 86.01.105 and CA.82.02.105 Documentation Policy
CA.40.01.111 Tuberculin Skin Testing TST
CA.40.02.112 Tuberculin Purified Protein Derivative Mantoux (Tubersol)
Product Monograph: Tubersol®; Tuberculin Purified Protein Derivative (Mantoux)

HPDTB(F)20 TB Skin Test Consent Form
HPDTB(F)21 Tuberculosis Test Certificate
HPDTB(F)28 TB Skin Test Consent form for the Workplace
HPDTB(F)29 TB Skin Test Consent Form for Stonehenge
HPDTB(FS)3 2-step Tuberculosis (TB) Skin Test
HPDTB(FS)4 fact sheet Tuberculosis or TB Skin Test
CHDPTB(F)5 Positive Tuberculin (TB) Skin Test form

CONTACT FOR INQUIRIES

Manager, Control of Infectious Diseases

APPROVED BY

Director, Health Protection