Abstract: Objective To analyze the tuberculin test results in the middle school freshmen in Shanxian County of Heze City in 2020 so as to understand the infection status of Mycobacterium tuberculosis in the students. Methods Freshmen were included from 3 boarding senior high schools and 37 boarding junior high schools under the administration of Shanxian County, and underwent tuberculin test (PPD test) from October 2020 to January 2021. The difference in positive and strong positive rates in students of different grades, genders and regions. Results Of the 15 994 students, positive rate and strong positive rate was 5.11% and 0.43%, respectively. No active tuberculosis infection was found. Positive rate and strong positive rate were 7.58%(547/7 219) and 0.82%(59/7 219), 3.08%(270/8 775) and 0.10%(9/8 775), respectively for high school freshmen and junior school freshmen, with statistical difference among students of different grades(χ２=165.484, 47.791, respectively; both P<0.05). The positive and strong positive rates were 7.47%(315/4 215) and 0.66%(28/4 215) for male high school students, 7.72%(232/3 004) and 1.03%(31/3 004) for high school females; 3.39%(61/4 754) and 0.08%(4/4 754) for male junior school students, 2.71%(109/4 021) and 0.12%(5/4 021) for junior school females, respectively. The difference was insignificant among genders (χ２=0.156, 2.925; χ２=3.337, 0.344, respectively, all P>0.05).  Students from urban areas had higher positive and strong positive rates than those from townships[4.95%(161/3 253) and 0.28%(9/3 253) vs. 1.97%(109/5 522) and 0]. The difference was significant(χ２=60.767, 15.293; both P<0.05). Conclusion PPD test is an important approach to tuberculosis screening in newly enrolled students, and of great significance in prevention and control of tuberculosis transmission among students in boarding schools, especially in high school students. 

Key words: Tuberculosis, Tuberculin test, Freshmen, Middle school