Sputum specimens examination in tuberculosis outpatient laboratory of Chaoyang district, Beijing from 2013 to 2021

Objective To analyze the performance of sputum examination in tuberculosis (TB) clinic in Chaoyang district of Beijing from 2013 to 2021, and provide evidence for the early detection and effective prevention and control of TB.

Methods Sputum examination data in TB cases diagnoses from 2013 to 2021 were collected for retrospective analysis. Meanwhile, the clinical data of outpatient management were used in statistical analysis.

Results From 2013 to 2021, a total of 8 826 suspected TB patients were admitted, in whom 2189 were clinically diagnosed with TB and registered for management. Sputum smear and culture were performed for all confirmed patients in case management, and the positive detection rates of both methods decreased year by year. Linear trend χ² test showed that the positive rates of sputum smear(χ ²=45.110, P < 0.001) and culture decreased with year ( χ²=8.820, P=0.003). In the analysis on the effectiveness of three methods for the confirmation of TB, the sensitivity and specificity rates of smear, culture and GeneXpertMTB/RIF were 37.46% and 91.53%, 46.23% and 79.73%, and 55.38% and 86.09%, respectively. The χ² test results showed that from 2013 to 2021, the etiological positive rate between the cases registered in Beijing and those registered in other areas had significant difference in 2016(χ²＝4.478, P =0.034) and 2017 ( χ²＝5.771, P=0.016). The comparison of annual etiological positive rate between men and women showed no significant difference , but the differences in annual etiological positive rate between sputum smear with different characteristics and culture were significant (P<0.001).

Conclusion From 2013 to 2021, the prevention and control of TB in Chaoyang was improved year by year, and the confirmation rate of TB increased year by year. The quality of sputum sample is important for the positive rate of TB detection,