Investigation and Analysis on Tuberculosis Outbreak Aggregated in a Vocational Middle School of Yixing City

Objective To identify the occurrence and interrelation of two tuberculosis outbreaks in a school by analyzing the circumstance of the school.

Method A retrospective investigation on the first case and the whole epidemic situation of the tuberculosis outbreak was carried out, the related factors were further explored by on-site epidemiological investigation.

Results There were 24 patients with active pulmonary tuberculosis, including 6 smear-positive patients, 15 smear-negative patients and 3 tuberculous pleurisy patients, and 83.33% of them were from the same class of the first case. In which, 8 cases were in the first outbreak and 16 cases were in the second outbreak. Typical initial symptoms of the first case were cough, sputum and other signal symptoms. However, the patient had not been diagnosed and suspended from the class until the end of the semester.

Conclusion Delayed diagnosis of the first smear-positive case and the close contacting classmates had refused to the PPD test and preventive medication, along with the follow-up survey was not in time led to further spread of outbreaks.