Abstract: Objective: To understand the situation and trend of drug resistance of tuberculosis patients in Guangdong Province from 2016 to 2020, so as to provide scientific basis for the prevention and control of drug-resistant tuberculosis. Methods: A total of 92851 patients with active pulmonary tuberculosis from 32 drug resistance surveillance sites in Guangdong Province from January 1, 2016 to December 31, 2020 were collected. The clinical information of the subjects was collected, the sputum samples were smeared, isolated and cultured, and the positive strains in culture were identified. A total of 30362 isolates of Mycobacterium tuberculosis (MTB) were obtained. The drug sensitivity test of 9 anti-tuberculosis drugs (isoniazid (INH), rifampicin (RFP), ethambutol (EMB), streptomycin (Sm), kanamycin (Km), ofloxacin (Ofx), capreomycin (Cm), propylthionicotinamide (Pto) and sodium aminosalicylate (PAS) was carried out on MTB isolates by proportional method, and the drug resistance of the strains was analyzed. Results: The total drug resistance rate of 30362 strains was 26.75% (8121/30362), the multidrug resistance rate was 3.34% (1014/30362), the single drug resistance rate was 15.88% (4820/30362), and the multidrug resistance rate was 7.53% (2286/30362). The resistance rate of the strain to any one of the nine anti-tuberculosis drugs from high to low was Sm (14.59%, 4430/30362)>INH (9.25%, 2810/30362)>RFP (6.22%, 1887/30362)>EMB (5.72%, 1737/30362)>Ofx (3.03%, 920/30362)>Pto (3.00%, 912/30362)>PAS (2.25%, 684/30362)>Cm (2.00%, 606/30362)>Km (1.63%, 494/30362), the difference was statistically significant (χ²=8889.800, P<0.01). Of the strains, 27783 were isolated from primary patients and 2579 strains were isolated from retreated patients. The drug resistance rate and multidrug resistance rate of retreated patients were significantly higher than those of primary patients (35.32% (911/2579) vs. 25.95% (7210/27783), χ ²=105.800, P<0.01; 10.35% (267/2579) vs. 2.69% (747/27783), χ ²=265.700, P<0.01). During the five years, the multidrug resistance rate of newly treated patients showed an upward trend (2.76% (152/5502) in 2016 and 3.19% (166/5203) in 2020), and the drug resistance rate of retreated patients showed a downward trend (38.85% (169/435) in 2016 and 35.02% (173/494) in 2020), the difference was statistically significant (χ_trend²=6.584 and 6.334, P=0.010 and 0.012, respectively). The drug resistance rate and multidrug resistance rate of the strains from the Pearl River Delta region were significantly higher than those from the eastern and northwestern regions of Guangdong Province (27.35% (4540/16597) vs. 26.02% (3581/13765), χ ²=6.886, P=0.009; 3.59% (596/16597) vs. 3.04% (418/13765), χ ²=3.879, P=0.049). Conclusion: The epidemic situation of drug-resistant tuberculosis in Guangdong Province is still serious. Rifampicin resistance, drug resistance of newly treated patients and drug resistance of tuberculosis in floating population should be paid special attention.

Key words: Tuberculosis, Drug resistance, bacterial, Population surveillance