Evaluation and Comparison of Molecular and Conventional Diagnostic Tests for Detecting Tuberculosis in Korea, 2013

Abstract

ObjectivesA fast and accurate diagnosis is necessary to control and eliminate tuberculosis (TB). In Korea, TB continues to be a serious public health problem. In this study, diagnostic tests on clinical samples from patients suspected to have TB were performed and the sensitivity and specificity of the various techniques were compared. The main objective of the study was to compare various diagnostic tests and evaluate their sensitivity and specificity for detecting tuberculosis.MethodsFrom January 2013 to December 2013, 170,240 clinical samples from patients suspected to have TB were tested with smear microscopy, acid-fast bacilli culture, and real-time polymerase chain reaction (PCR). The test results were compared and data were analyzed.ResultsA total of 8216 cultures tested positive for TB (positive detection rate, 4.8%). The contamination rate in the culture was 0.6% and the isolation rate of nontuberculous mycobacteria was 1.0%. The sensitivity and specificity of smear microscopy were 56.8% and 99.6%, respectively. The concordance rate between the solid and liquid cultures was 92.8%. Mycobacterium isolates were not detected in 0.4% of the cases in the liquid culture, whereas no Mycobacterium isolates were detected in 6.8% of the cases in the solid culture. The sensitivity and specificity of real-time PCR for the solid culture were 97.2% and 72.4%, respectively, whereas the corresponding data for the liquid culture were 93.5% and 97.2%.ConclusionThe study results can be used to improve existing TB diagnosis procedure as well as for comparing the effectiveness of the assay tests used for detecting Mycobacterium tuberculosis isolates.

Rapid Detection of Rifampicin- and Isoniazid-Resistant Mycobacterium tuberculosis using TaqMan Allelic Discrimination

“…Many studies used real-time PCR for detection of mutations in rpoB and katG genes 17 , 18 , 19 , 20 , 21 but, to our knowledge, this study is the first one that uses the TaqMan allelic discrimination without MGB. Our study suggests that drug-resistant M. tuberculosis can be detected by pattern's curve or Ct with TaqMan probes without MGB in real-time PCR.…”

Retropharyngeal SOL: An unusual presentation of a multifaceted entity

“…Park et al . [ 10 ] in a large-scale study reported the sensitivity and specificity of smear microscopy as 56.8% and 99.6%, respectively, while that of real-time PCR for solid culture was reported as 97.2% and 72.4%, respectively, and for liquid culture was 93.5% and 97.2%, respectively. Congruent results have been reported recently by Agarwal et al .…”

Vantagens e usos do teste rápido molecular para tuberculose: uma revisão integrativa

“…Outro grande problema na sua implantação é o custo elevado da tecnologia em comparação com baciloscopia e a necessidade de calibração anual, que é susceptível de ser difícil em ambientes remotos. 12,15,17 No entanto, a Foundation for Innovative New Diagnostics (FIND) negociou reduções substanciais nos custos para uso no setor público em 116 países de alta carga de tuberculose e de baixa e média renda. O custo de capital inicial para o instrumento GeneXpert nesses ambientes (cerca de US$ 17.500 por instrumento de 4 módulos) é consideravelmente maior do que para microscopia (cerca de US $ 1.500 por diodo emissor de luz [LED] microscópio), mas muito menor do que para a cultura convencional, especialmente tendo em vista que se pode dispensar a necessidade de caros equipamentos de biossegurança.…”

“…Estudo realizado na Coreia 22 relatou sensibilidade e especificidade da baciloscopia de 56,8% e 99,6%, respectivamente. Enquanto, a sensibilidade e especificidade do Xpert ® MTB/RIF para a cultura sólida foram 97,2% e 72,4%, respectivamente, enquanto que os dados correspondentes para a cultura líquida foi de 93,5% e 97,2%.…”