Abstract:

Objective To understand the surveillance results at the tuberculosis drug resistance surveillance sites in Chongqing area for a reference for following prevention and control of drug-resistant tuberculosis. Methods The surveillance data were collected from 2013 to 2024 from the two national-level tuberculosis drug resistance surveillance sites in Fengdu County and Fengjie County of Chongqing, and analyzed regarding the drug resistance patterns, categories and spectrums of six common anti-tuberculosis drugs: isoniazid (INH), rifampicin (RFP), streptomycin (Sm), ethambutol (EMB), ofloxacin (Ofx) and kanamycin (Km) among the patients with etiologically confirmed positive tuberculosis. The Joinpoint regression model was used to analyze the trends in drug resistance. Results A total of 2 144 tuberculosis patients were included in the study. The overall drug resistance rate was 19.96% (428/2 144), and the multidrug resistance rate accounted for 4.34% (93/2 144). The rate of drug resistance and multidrug resistance were significantly higher in retreated patients than in primary treated patients (34.88% vs. 17.92%, 14.73% vs. 2.92%; χ²= 40.869, 76.316, respectively; both P<0.05). Patients with a history of dust exposure or pneumoconiosis exhibited a higher drug resistance rate than those without such history (30.00% vs. 19.15%, χ²=10.903, P<0.05). The resistance rate for the six drugs ranking from high to low was Sm (9.98%, 214/2 144), INH (9.75%, 209/2 144), Ofx (6.11%, 131/2 144), RFP (5.64%, 121/2 144), EMB (2.75%, 59/2 144), and Km (2.10%, 45/2 144). In terms of drug resistance spectrum, the most prevalent drug resistance profile was mono-resistance to Ofx (3.78%, 81/2 144). From 2013 to 2024, the multidrug resistance rate exhibited a decreasing trend (AAPC=-6.581, P<0.05), yet the resistance rates of Km and Ofx showed an upward trend (AAPC=13.934 and 11.862, respectively; both P<0.05). The overall drug resistance, multidrug resistance rates, pre-extensively drug resistance rates and the resistance rates to INH, RFP, EMB and Ofx at the surveillance site in Fengjie County were all significantly higher than those at the site of Fengdu County (χ²=9.822, 13.035, 12.191, 6.811, 7.349, 12.650 and 23.102, respectively; all P<0.05). Conclusion The drug resistance situation of tuberculosis in Chongqing remains severe. Among them, single resistance to Ofx is the most common, and the drug resistance rate of second-line anti-tuberculosis drugs shows an upward trend. The risk of drug resistance is higher in retreated patients as well as those exposed to dust or with a history of pneumoconiosis. In the future, it is necessary to strengthen the screening of drug resistance to second-line anti-tuberculosis drugs, and enhance the monitoring and standardized diagnosis and treatment management of drug resistance in the key populations.

Key words: Mycobacterium tuberculosis, Drug resistance, Surveillance, Chongqing Municipality