Development of the quality of diagnostic test for rapid molecular biology of Mycobacterium

Abstract

Mycobacterium tuberculosis or TB is a leading cause of both morbidity and mortality in many countries worldwide. Thailand is one of the highest TB-burden countries and currently the estimate of the multi-drug resistant TB (MDR-TB) burden is increasing overtime. To response to fight against Mycobacterium tuberculosis epidemic in Thailand, it is a need to develop and support new technologies and strategies that would allow the expansion of prevention, diagnosis and treatment programs. Molecular technique for detecting Mycobacterium tuberculosis is an efficient tool for diagnosis and treatment of Mycobacterium tuberculosis. In Thailand, this technique has been increasingly used for diagnosis Mycobacterium tuberculosis. The high quality of laboratory results can have a positive impact on diagnosis.  The External Quality Assessment (EQA) is one of the major mechanisms of to ensure the quality of laboratory according to professional standards and other international standards.  However, no any agency in the country runs the EQA program for TB molecular technique.  Therefore, the national TB reference laboratory has developed the EQA sample for TB molecular diagnosis test for using in external quality assessment program for TB molecular test in Thailand. To prepare the EQA sample, Dry Tube Culture Spot (DCS) is selected. The concentration of TB bacilli is by comparing with Macfarland No.1 and equal 107cell/ml. Using 0.1 ml of this solution is put in the tube and dry. We use 5 difference stains of TB to prepare DCS. Each stain was prepared 100 tubes and then random for checking 12 tubes (12%). The just in total of 60 tubes; 30 tubes were performed by using LPA: Genotype (HAIN test) and other 30 tubes using Xpert MTB/RIF test for rechecking. The result showed that 100% and 97% in comparable with standard by using LPA genotype (HAIN test) and Xpert MTB/RIF test, respectively.