New tools for tuberculosis diagnosis

[摘要] Background: In recent decades, new tools have been developed to decrease the time of diagnosis of infections with Mycobacterium tuberculosis.Objective: To introduce the new tools for identification of M. tuberculosis and compare the results with culture in Löwenstein Jensen.Methods: 1 368 samples received at the National Tuberculosis Reference Laboratory of the IPK from August 2010 to August 2014. After samples processed were inoculated in parallel on Löwenstein Jensen and BacT ALERT. The results obtained are analyzed and compared with respect to the total isolates, time detection of growth and contamination rate, the performance indicators of BacT ALERT also calculated.Results: By Bact / ALERT were identified Mycobacterium tuberculosis in 126 (98.5 %) samples and 116 (88.5 %) by Löwenstein Jensen. The time detection of growth of Mycobacterium tuberculosis by BacT / ALERT was 16.6 days, two times lower than that obtained by the Löwenstein Jensen (35.5 days). The contamination rate by Bact / ALERT and Löwenstein Jensen was 11 % and 7.8 %, respectively. The sensitivity, specificity and Youden index was 99.1 %, 99.0 % and 0.98, respectively; and the validity index was 99 %.Conclusions: Bact / ALERT system proved a useful method because it significantly shortened the time of tuberculosis diagnosis and start allowing treatment in a timely manner, especially in smear-negative patients. The combined use of liquid medium and Löwenstein Jensen assured recovery of all strains of Mycobacterium tuberculosis.

[学科分类] 传染病学

[关键词] Mycobacterium tuberculosis;BacT ALERT 3D system;Löwenstein Jensen;nontuberculous mycobacteria