Abstract:

Objective To analyze the drug resistance of Mycobacterium tuberculosis isolates from pulmonary tuberculosis patients in Gansu Province. Methods A total of 30 county-level designated tuberculosis medical institutions in Gansu Province were selected as surveillance sites by means of cluster stratified equal proportion random sampling method. Between Sep 2014 and Aug 2017, 1931 isolates from sputum culture positive pulmonary tuberculosis patients older than 15 years were detected by the proportional phenotypic drug sensitivity test which reported results for ten anti-tuberculosis drugs (isoniazid (INH), rifampicin (RFP), ethambutol (EMB), streptomycin (Sm), kanamycin (Km), amikacin (Am), ofloxacin (Ofx), capreomycin (Cm), isoniazid (Pto), and sodium p-aminosalicylate (PAS)). Results For the tested 1931 isolates, the overall resistance rate, multidrug-resistance rate, monoresistance rate, polydrug resistance rate, and widespread resistance rate was 26.26% (507/1931; 95%CI: 24.30%-28.22%), 8.44% (163/1931; 95%CI: 7.20%-9.68%),11.39% (220/1931; 95%CI: 9.98%-12.81%), 6.42% (124/1931; 95%CI: 5.33%-7.51%), and 0.41% (8/1931; 95%CI: 0.13%-0.70%), respectively. Among them, there were significant differences in the overall resistance rates (25.45% (462/1815; 95%CI: 23.45%-27.46%) and 38.79% (45/116; 95%CI: 30.10%-47.84%), respectively) and multidrug-resistance rates (7.82% (142/1815; 95%CI: 6.59%-9.06%) and 18.10% (21/116; 95%CI: 11.10%-25.11%), respectively) between isolates from initial-treatment and retreatment patients (χ ²=5.357,P=0.021;χ²=11.623,P=0.001); And the overall resistance rates of isolates from initial-treatment patients in males and central areas (26.22% (284/1083) and 24.96% (158/633), respectively) were significantly lower than those of isolates from retreatment patients (41.49% (39/94) and 51.43% (18/35), respectively), and the differences were statistically significant (χ²=5.241,P=0.022;χ²=5.888,P=0.015). The top three drug resistance rates to 10 anti-tuberculosis drugs were found to be INH (16.78%,324/1931), EMB (15.38%,297/1931), RFP (10.10%,195/1931). It is estimated that the number of new drug-resistant, multidrug-resistant and extensively drug-resistant patients in Gansu Province per year is 2341-2764, 665-940 and 5-70 respectively. Conclusion Drug resistance of tuberculosis is serious in Gansu Province, and the resistance to first-line anti-tuberculosis drugs is common. Furthermore, the drug resistance of newly treated patients should be paid more attention.

Key words: Tuberculosis,pulmonary, Tuberculosis,multi-drug resistant, Medicine sensitiveness test, Drug resistance monitoring, Data interpretation,statistical