Abstract: Objective To explore the status of drug resistant pulmonary tuberculosis and analyze the risk factors contributing to drug resistance of retreatment patients in Guangxi. Methods A prospective survey was conducted by consecutively recruiting patients with smear-positive pulmonary tuberculosis (TB) in 30 TB control institutes from 2010 to 2011 in Guangxi. Forty-one new cases and 22 retreatment cases were assigned to be recruited in each institute. Information on patient’s socioeconomic status and previous clinical history was collected by questionnaire. Identification of Mycobacterium tuberculosis complex (MTBC) was based on para-nitrobenzoic acid culture test. Drug susceptibility tests (DST) were performed for isoniazid, rifampicin, ethambutol, streptomycin, kanamycin and ofloxacin. Univariate analysis was applied to each variable of patients’ socioeconomic and clinic information to assess the risk factors associated with drug resistance. Results One thousand five hundred and forty-five isolates collected in the survey were identified as MTBC. Among them, 17.22% (266/1545) cases were resistant to at least one anti-TB drugs, drug resistant rates of new smear positive cases and retreatment cases were 11.97% (142/1186) and 34.54% (124/359) respectively. The drug resistant rate of retreatment cases was higher than new cases (χ²=98.473, P=0.000). 6.28% (97/1545) cases were multidrug-resistant tuberculosis (MDR-TB), 2.45% (29/1186) for new cases and 68 (18.94%,68/359) for cases treated previously. MDR-TB rate was much higher in previous treated cases than new cases (χ²=127.450, P=0.000). 0.19% (3/1545) of cases was found to be extremely drug-resistant tuberculosis (XDR-TB), all of whom were retreatment cases (0.84%, 3/359). Univariate analysis of drug resistance of retreatment cases indicated that female (OR=2.009, 95%CI: 1.145-3.523, χ²=6.062, P=0.014), Zhuang nationality (OR=1.609, 95%CI: 1.024-2.529, χ²=4.289, P=0.038), selecting general hospital for first health care seeking (OR=1.967, 95%CI:1.210-3.198, χ²=7.565, P=0.006), more than once prior anti-TB treatment (OR=4.128, 95%CI:2.506-6.801, χ²=33.160, P=0.000), nonstandard treatment regimen (OR=3.419, 95%CI:1.952-5.988, χ²=19.775, P=0.000), and low family income (OR=4.777, 95%CI: 1.117-20.435, χ²=5.336, P=0.021) were found to contribute to higher trend of MDR-TB.  Conclusion Prevalence of drug resistant TB in Guangxi is lower than the national level. Results indicates that female, Zhuang nationality, low family income, seeking health care in non-designated institute and repeated treatment may be the risk factors of drug resistance.

Key words: Tuberculosis, pulmonary/prevention &, control, Mycobacterium tuberculosis, Drug resistance, bacterial, Guangxi