Abstract:

Objective: To analyze the positive detection rates, positive detection contribution rates and their changes of three etiological testing methods on detecting pulmonary tuberculosis (PTB) from 2019 to 2023, in order to provide a basis for further improving etiologically positive rate of PTB patients and optimizing the configuration strategy of PTB testing methods. Methods: Data of active PTB patients registered and managed by the Tuberculosis Department of Beijing Center for Disease Prevention and Control from 2019/01/01 to 2023/12/31 was extracted from the Tuberculosis Information Management System, a subsystem of China Disease Prevention and Control Information System, and then combined with information of tuberculosis laboratory test results such as acid-fast staining of Mycobacterium tuberculosis smear (referred to as sputum smear), Mycobacterium tuberculosis isolation and culture (including solid acidic Lowenstein-Jensen culture method or BACTEC^TMMGIT 960 liquid culture method, referred to as sputum culture), and GeneXpert MTB/RIF test, to calculate detection rates, positive rates of these three etiological detection methods, and analyze their positive detection contribution rates. The positive rates and contribution rates of sputum culture and molecular biological methods on detecting PTB among smear-negative patients were also calculated and analyzed. Results: A total of 1043 patients were registered for management at the Tuberculosis Department of Beijing Center for Disease Prevention and Control from 2019 to 2023. Coverage rate of testing by sputum smear, culture or molecular testing was 99.1% (1034/1043). The overall etiologically positive rate was 56.0% (579/1034). The overall positive rates of sputum smear, sputum culture and molecular detection were 29.3% (302/1032), 41.9% (402/959) and 43.5% (428/985), respectively, with statistically significant difference (χ²=52.088, P<0.001). The positive rate of sputum smear showed a statistically significant downward trend from 2019 to 2022 ({\chi }_{\mathrm{t}\mathrm{r}\mathrm{e}\mathrm{n}\mathrm{d}}^2=12.802, P<0.001). In patients tested by all three methods, the positive rates of sputum smear, sputum culture and molecular detection were 29.2% (268/919), 42.5% (391/919) and 44.0% (404/919), respectively, which was statistically significantly different (χ²=51.740, P<0.001). The positive detection contribution rates of the three methods were 50.4% (268/532), 73.5% (391/532), 75.9% (404/532), respectively, the difference was statistically significant (χ²=95.195, P<0.001). Among them, the positive rate and positive contribution rate of sputum smear showed a downward trend from 2019 to 2022, and the differences were statistically significant ({\chi }_{\mathrm{t}\mathrm{r}\mathrm{e}\mathrm{n}\mathrm{d}}^2=14.426, P<0.001, {\chi }_{\mathrm{t}\mathrm{r}\mathrm{e}\mathrm{n}\mathrm{d}}^2=15.020, P<0.001). From 2019 to 2023, there was no significant difference in the total positive detection rates and positive detection contribution rates between sputum culture and molecular biological detection among smear negative patients (χ²=0.098,P=0.755,χ²=0.212, P=0.645). From 2019 to 2023, among all 532 etiologically positive patients who had undertaken all three detection methods, the rates of only being detected positive by sputum smear, culture and molecular biological test were 3.2% (17/532), 16.2% (86/532) and 17.1% (91/532), respectively, the difference was statistically significant (χ²=60.216, P<0.001). Conclusion: Compared with traditional detection methods, molecular biological detection technology has higher positive detection rate and positive contribution rate. It is suggested to further promote molecular biological detection technology to help improving the overall efficiency of tuberculosis diagnosis.

Key words: Mycobacterium tuberculosis, Tuberculosis, pulmonary, Molecular diagnostic techniques, Comparative study