Abstract: Objective  To evaluate the quality control results of drug susceptibility testing (DST) of MTB in order to standardize and improve the external quality assurance (EQA)system of DST in Henan province.   Methods  In accordance with the TB diagnostic laboratory testing procedures, six laboratories intend to be evaluated performed the proportional method for DST proficiency testing. A total of 58 strains were issued by Henan provincial reference laboratory (PRL) to each testing laboratory, and the results were reported to PRL and made comparison with the standard results.  Results  The consistency of first line drug INH,RFP, S and EMB was 91.0%（151/166）,95.8%(159/166),89.2%(148/166) and 77.1%(128/168) respectively. The average consistency of second-line drugs reached 94.9%(683/720).  Conclusion  The DST for first line INH and RFP and four second line drugs in six laboratories evaluated met the WHO and national requirement. However, the EMB testing should be further improved.

Key words: Mycobacterium tuberculosis, Microbial sensitivity tests, Quality control, Henan province