Risk factors associated with kanamycin-resistant tuberculosis in a Beijing tuberculosis referral hospital

The rapidly increasing number of multidrug-resistant tuberculosis (MDR-TB) cases worldwide underlines the necessity for the rational use of key second-line drugs such as kanamycin. In this study, we determined the prevalence of, and risk factors associated with, kanamycin-resistant tuberculosis (TB) in 309 Hospital, Beijing, China, with the aim of providing information for better case management in order to minimize further development of extensively drug-resistant TB (XDR-TB). Drug susceptibility testing results and clinical data were retrospectively analysed for hospitalized TB patients for whom such data were available in 309 Hospital for the period 1997-2009. Univariate and multivariate analyses were used to determine the risk factors associated with kanamycin-resistant TB. During 1997-2009, 553 (14.4 %) of 3843 tested Mycobacterium tuberculosis isolates from hospitalized TB patients were kanamycin-resistant. The increasing trend of resistance to kanamycin was reversed since 2000. The independent risk factors associated with kanamycin-resistant TB included living in urban areas [adjusted odds ratio (OR) = 1.89], being retreated for repeat cases (adjusted OR = 1.60), being smear-positive for acid-fast bacilli at admission to the hospital (adjusted OR = 1.39), having ofloxacin-resistant (adjusted OR = 1.61) or para-aminosalicylic acid-resistant TB (adjusted OR = 1.47), having MDR-TB (adjusted OR = 5.10), having MDR-TB plus ofloxacin resistance (adjusted OR = 4.27) and having poly-resistant TB (adjusted OR = 3.94). The remaining rate of kanamycin resistance is still high despite the reversal of the increasing trend during the past decade. Surveillance of kanamycin resistance, especially among high-risk populations, should be continued to closely monitor trends so that appropriate action can be taken.