Objective: To determine the pattern of resistance to second-line drugs (SLDs) in patients with tuberculosis (TB) in Shanghai, China.
Methods: All sputum culture positive patients detected at each district/county TB hospital/clinic in Shanghai during January to December 2009 were enrolled. First-line drug susceptibility testing was routinely performed for each clinical isolate. All clinical isolates with any resistance to first-line anti-TB drug were tested for second-line drug susceptibility.
Results: Of the 431 TB patients with any resistance to first-line anti-TB drugs included in this study, 27.8% (120/431) were resistant to any SLDs tested. The rank of drug resistance was as follows: ofloxacin (68/431, 15.8%) > kanamycin (37/431, 8.6%) > para-aminosalicylic acid (35/431, 8.1%) > capreomycin (28/431, 6.5%) > amikacin (23/431, 5.3%) > prothionamide (8/431, 1.9%). Mono-resistance to SLD was the most predominant pattern. Among patients with resistance to SLD, the percentages of mono-resistance were 2/2, 20/36, 22/24 and 43/58 for rifampin-resistant group, isoniazid-resistant group, other-resistant group, and MDR group, respectively.
Conclusion: The high prevalence of resistance to SLDs in TB patients suggests the necessity to strengthen the TB control program for drug-resistant TB in Shanghai.