TB Testing Requirements

Please read this entire page and see the PPD algorithm below.

In order to shadow in the Emergency Department at Barnes-Jewish Hospital, all students are required to complete a test to rule out the presence of latent tuberculosis infection. There are two types of tests that are offered:

The first test is an intradermal skin test know 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 to see if there has been a strong 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 and 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.

The MedPrep course director recommends 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 health care 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 after one's blood is drawn and the test doesn't need to be repeated after a week. Just like the PPD tests, however, the QuantiFERON-TB Gold test must be completed within 12 months of shadowing.

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. 

Student's who have had one PPD test within the past 12 months that was negative may opt to simply have one more PPD test performed. BOTH PPD tests, however, must have been completed within 12 months of shadowing to be accepted. If a student has had a T-spot test performed in the past 12 months, that will be accepted in lieu of a QuantiFERON-TB Gold test and no further testing is required. 

Where can I have the test performed?

Both the PPD series and the QuantiFERON-TB Gold test are available at Washington University Student Health Services located on the South 40. A single QuantiFERON-TB Gold test costs approximately $25 while two PPD tests costs a total of $20 (i.e. $10 for each PPD). Again, the course director recommends the QuantiFERON-TB Gold test.

Once a student has registered for MedPrep II, their name will appear on the class roster and the SHS service will know that the student may be coming in to have the test performed. There is no need for the student to make an appointment and the student will not be charged if they do not have the test done at SHS. Once a student is on their list, they will receive a secure message from SHS which can read by logging on to the student portal on the SHS website. In the message the student will be reminded to come into the clinic and go straight to the lab, to bring their insurance card, and the hours the clinic/lab will be open. Again, an appointment is not necessary. It will take 1-2 weeks to get the results back and these must be received by Ms. Gerrity (the student will send to Ms. Gerrity) before the first day of class. 

If a student is unable to have the testing performed at Student Health Services, then it can be performed by the student's primary care physician or at a Walgreens Take Care Clinic. If a student will be having these tests done within 50 miles of the campus, they will need to have a referal letter from Student Health Services if they want the cost of the tests covered by their student health insurance. Students can go to the Walgreens Take Care Clinic, enter their zip code and find a location close to them. Student Health Services is the preferred location, however, to have either of these tests done. 

If you have ever had a positive test...

Students who have had a positive PPD, QuantiFERON-TB Gold, or T-spot test must complete the Tuberculin Positive History Review Form noting the absence of any symptoms of active TB. This form must then be turned in to Erin Gerrity in the Plant Growth Building, Room 105. A chest x-ray will then need to be performed within 12 months of shadowing to rule out the presence of active TB. This can also be scheduled through Student Health Services

Any student with a positive test result should discuss the results with a physician at Student Health Services or with their primary care physician. A positive test does NOT preclude a student from shadowing in MedPrep II. But a student must be free of symptoms of active TB as indicated on the Tuberculin Positive History Review Form and must have a chest x-ray that shows no evidence of active TB. 

All tests results, chest x-ray results, and/or Tuberculin Positive History Review forms must received by Erin Gerrity in the Plant Growth Building, Room 105 within 30 days of registration or students will forfeit their spot in the course. If the student is opting for the 2 PPD tests, the results of BOTH tests must be received within 30 days. Note: The 30 day time limit only applies to the fall and spring semesters. For the summer semester, these items must be received by the first class day. 

Still have questions? The PPD algorithm below may help clarify the process. Again, the QuantiFERON®-TB Gold test is preferred over the PPD test.