Evaluation of screening methods for the students who had close contact with pulmonary tuberculosis patients in Shanghai

Objective To evaluate the current screening methods for the students who were in close contact with tuberculosis patients， that could accurately identify the preventive treatment subjects， and to improve the tuberculosis prevention and control in Shanghai schools.

Methods The freshman/sophomore who were in close contact with active tuberculosis patients in the colleges in 2019 were recruited. All the subjects underwent both tuberculin skin test （TST） and QuantiFERON-TB gold in-tube （QFT） test at the enrollment. After signed the informed consent， all of the participants filled in a questionnaire and determined their baseline tuberculosis infection status. They were followed up for 2 years to monitor the conversion of infection status and the incidence of tuberculosis.

Results Four of 9 （44.4%） positive participants had conversion to negative results， and 5 of 300 （1.7%） negative participants had conversion to positive during the 2-year follow-up， one of which was diagnosed with active tuberculosis. We assessed diagnostic agreement between QFT and TST at different cut-off values. The highest coincidence rate was 94.0% when choosing 15 mm as the cut-off value， with Kappa coefficient of 0.45 （95%CI： 0.32‒0.59）.

Conclusion Although stricter than the national work requirements， the prevention and control of tuberculosis in Shanghai schools still need to be carried out meticulously. It's necessary to strengthen daily prevention and control measures， and improve the ability of management.