Prior to shadowing in Barnes-Jewish Hospital, students are required to demonstrate that they have been screened to rule out the presence of active or latent TB infection.
The test that is currently recommended is the QuantiFERON®-TB Gold test. This test is a blood test that can be obtained at Student Health Services (SHS) on the South 40.
Students who secure a spot in MedPrep II should hold on any TB testing until notified by the course coordinator. Please check your email daily for this email.
Why a QuantiFERON®-TB Gold test instead of a PPD test?
There are two types of tests that are available to rule out the presence of TB infection.
The first test is an intradermal skin test known as the PPD (Purified Protein Derivative). This test is also known as the Mantoux Test or the Tuberculin Sensitivity Test (TST).
In this test, a small injection is made underneath the skin on the forearm. 48-72 hours later the patient must return to their provider’s office to have the injection site checked for the extent of skin reaction to the injection.
If an individual prefers to have this test performed, Barnes-Jewish Hospital requires two PPDs to be performed at least one week apart from each other with BOTH tests to be performed within 12 months of shadowing.
The second test is a blood test known as an Interferon-Gamma Release Assay (IGRA). There are two main types of IGRA tests available – the QuantiFERON®-TB Gold test and the T-spot test. In contrast to the PPD tests, only one QuantiFERON®-TB Gold test or T-spot test is required.
We recommend that students have an IGRA (i.e. a QuantiFERON®-TB Gold test) performed. The reason is that to have two PPD tests completed, the student must make an appointment with their provider a total of 4 times over a period of 10-14 days (i.e. having the 1st PPD “placed,” returning 48-72 hours later to have it “read,” and then returning a week after the first PPD placement to have the 2nd PPD placed and then again returning 48-72 hours later to have it read).
With the QuantiFERON®-TB Gold test, there is no need to return to the provider’s office for a second test.
Just like the PPD tests, however, the QuantiFERON®-TB Gold test must be completed within 12 months of the start of this course.
The other benefit of having the QuantiFERON®-TB Gold test performed instead of a PPD is the lower rate of false positive test results for those students who have had a BCG vaccination when they were a child. In fact, if a student has had a BCG vaccination in the past, the QuantiFERON-TB Gold test is required.
What if I had a BCG vaccination in the past?
It the past it was believed that if you had a BCG vaccination, you would always have a positive PPD test. This is no longer believed to be the case.
If you had a BCG vaccination you will need to have a QuantiFERON®-TB Gold test) performed.
What if I've had a positive test in the past?
If you have had a positive test in the past, you will not need to have further testing performed. Instead, you will need to have a chest x-ray performed within one year of the start of this course to demonstrate no evidence of active TB and will need to complete the Tuberculin History Review Form.
The results of the chest x-ray and the review form should be submitted to Ms. Gerrity by the first day of class.
What if my QuantiFERON®-TB Gold test is positive?
If your QuantiFERON®-TB Gold test is positive, you will still be permitted to shadow but must demonstrate that you do not have active TB.
This requires the need to have a chest x-ray performed to demonstrate no radiographic evidence of active TB and completion of the the Tuberculin History Review Form to confirm that you have no clinical symptoms of active TB.
You should then discuss your positive test result with your physician to determine your next step.
The QuantiFERON®-TB Gold test results, the chest x-ray results, and the Tuberculin History Review Form should be submitted to Ms. Gerrity by the first day of class.