Investigation of Tuberculosis in a High School - San Antonio, Texas, 2012

On February 21, 2012, the San Antonio Metropolitan Health District (SAMHD) Tuberculosis Clinic was notified that two students at Madison High School had laboratory-confirmed pulmonary tuberculosis (TB). During March-September 2012, public health officials from SAMHD collaborated with the school district to conduct an outbreak investigation that included performing tuberculin skin tests (TSTs) on high-risk contacts of active TB patients. To ensure compliance, all TSTs were performed at the school. Initial screening was conducted as soon as a contact was identified and was followed by a second TST ≥8 weeks after the patients with active TB were removed from the school. All positive TSTs were confirmed with an interferon gamma release assay (IGRA) (T-Spot.TB, Oxford Immunotec, Inc.) performed by SAMHD laboratory services. IGRA tests can provide additional evidence of infection to encourage acceptance and adherence of foreign-born patients who believe their positive TST is attributable to Bacille Calmette-Guerin vaccination and might also prompt greater acceptance of treatment for latent TB infection compared with a positive TST alone.