P17
Evaluation of sensitivity and specificity of molecular tests for detecting the resistance of M. tuberculosis from the raw sputum and isolates strains
N Ciobanu(1) A Codreanu(1) N Turcanu(1) E Noroc(1) V Crudu(1)
1:Phthisiopneumology Institute, Chisinau, Moldova
Background. Late diagnosis and delays in susceptibility testing led to increased morbidity, mortality and ongoing transmission of the disease. Among the challenges in controlling TB, the rapid and accurate diagnostic tests for the detection of M. tuberculosis and its drug resistance is crucial.
The objective of this study was to evaluate the sensitivity and specificity of molecular methods for drug susceptibility testing of M. tuberculosis from the raw sputum and isolates strains.
Methods: For evaluate the sensitivity and specificity of molecular tests MTBDRplus and MTBDRsl for DST of M. tuberculosis, 1706 results directly from sputum was compare with their results from culture isolates. All results were compared with phenotypic DST of these culture strains.
Results: The discordances of molecular results from the raw sputa and M. tuberculosis strains: for INH – false susceptibility – 1,6 and false resistance – 2.9; for RIF - false susceptibility – 1,6 and false resistance – 2.6; for FQ- false susceptibility – 3,0 and false resistance – 3.9.
Conclusion: The MTBDRplus test have shown good specificity and sensitivity for INH and RIF from sputum compared with the genotipic and phenotypic results from culture strains. Routinely implementation of molecular DST from raw sputum can improve the capacity for early detection of MDRTB cases.