Setting: The Supranational Tuberculosis Reference Laboratory (NTRL), Bangkok, and Chiangrai Prachanukroh Hospital, Chiangrai, Thailand
Objective: To evaluate the diagnostic performance of newly developed line-probe assay (LiPA) kits in tuberculosis (TB) endemic settings.
Design: LiPA kits were used to evaluate 404 clinical isolates of Mycobacterium species and 163 sputum samples in Thailand.
Results: LiPA kits were able to identify M. tuberculosis, M. avium, M. intracellulare and M. kansasii with 100% sensitivity and specificity when compared with the commercially available AccuProbe assay. Testing of the LiPA kits for their ability to detect mutations in clinical isolates resistant to anti-tuberculosis drugs such as rifampicin, isoniazid, pyrazinamide and fluoroquinolones showed that the assay had very high sensitivity (65.9-100%) and specificity (98.2-100%) compared with drug susceptibility testing and DNA sequencing. LiPA had a sensitivity of 75.0-85.7% and a specificity of 96.4-100% in testing clinical sputum samples.
Conclusion: The novel LiPA kits have high sensitivity and specificity, and may enhance the rapid detection of first- and second-line anti-tuberculosis drug resistance, improving the selection of suitable chemotherapy agents to treat multidrug-resistant and extensively drug-resistant TB.