The CDC fact sheet you cited regarding BCG vaccination conflicted with the answer you provided (Item 93-6). You stated that “BCG-vaccinated patients should be skin-tested, with results interpreted using the same criteria as for those who have never been BCG-vaccinated.” According to the fact sheet, while skin testing is not contraindicated for persons who have been vaccinated, the size of the skin testing reaction is not a factor in determining whether the reaction is caused by latent TB infection (LTBI) or the prior BCG vaccination. Your answer was correct in that there is no contraindication, but could you clarify how one would interpret the results based on what appears to be conflicting information? Otherwise, what would be the purpose of skin-testing a BCG-vaccinated person?
—Jodi Roberts, MN, APRN, FNP, Marietta, Ga.
Some practitioners falsely believe that a small reaction in a person with BCG can be ignored and only considered caused by LTBI if the reaction is >15 mm. The CDC disputes this (Table 1). Patients with a history of BCG should be screened for LTBI using the same guidelines as those without a history of BCG. The size of the reaction should be judged against current guidelines regardless of a history of BCG vaccine. If a patient has a positive tuberculin skin test but no signs of infectious TB, treat for LTBI regardless of a history of BCG vaccine.
—Claire B. O’Connell, MPH, PA-C (102-20)