An investigation of Pulmonary Tuberculosis in a High School, Yanyaow Sub-district, Sawankhalok District, Sukhothai Province, September 14th - December 22nd, 2011

Abstract

On 14^th September 2011, the SRRT Sawankhalok hospital had received a notification from Sukhothai Provincial Health Office about a new case of pulmonary tuberculosis with sputum positive AFB. The case was a student from a high school in Sawankhalok District. Investigation on close contacts was conducted during 14^th September – 22^nd December 2011, with the aims to confirm diagnosis, describe epidemiological characteristics of the case and latent TB infection, and implement control measures for the outbreak.
We found that the index case of pulmonary tuberculosis was currently under treatment with CAT 1 regimen in a public general hospital. We identified 4 close contacts in household of the index case by using guideline of close contact investigation and all of them revealed negative for pulmonary TB. Among 46 close contacts in classroom of the index case, 12 teachers and 34 students revealed normal chest films and sputum AFB negative. But 6 of them had clinical symptoms and were suspected of tuberculosis. Of all close contacts who received tuberculin skin test (TST), 23 of them revealed TST positive at the first time and 5 were additional positive at the second time. All positive contacts were students and got Isoniacid (INH) treatment for latent tuberculosis infection (LTBI).
Behavior risks of LTBI in this study were overcrowding and living in poor ventilated and closed space airconditioned room. Control measures were implemented, including isolation of the index case, and providing treatment, big cleaning for all classrooms and health education for all students and teachers. No new patient was identified until 6 months after the implementation.