Japanese journal of infectious diseases
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Jpn. J. Infect. Dis. · Mar 2021
Real-World Performance Assessment of Xpert MTB/RIF Assay for Detecting Pulmonary Tuberculosis and Rifampin Resistance in a Single Tertiary Care Hospital in Korea.
This study aimed at evaluating performance of Xpert MTB/RIF (Xpert) regarding detection of pulmonary tuberculosis compared to acid-fast bacilli (AFB) smear and culture, and concordance of rifampin resistance with drug susceptibility test. Specimens simultaneously referred for AFB smear, culture, and Xpert during April 2015 to March 2018 were retrospectively reviewed. Sensitivity, specificity, and mean cycle-threshold (Ct) values of Xpert and rifampin resistance results were analyzed. ⋯ Rifampin resistance tested by Xpert and culture was 98.3% concordant. Region covered by probe E was the most frequently mutated (50.0%). Xpert showed reliable performance in detecting pulmonary tuberculosis in smear-positive/culture-positive specimens and further improvements are needed for smear negative/culture positive specimens.
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Jpn. J. Infect. Dis. · Mar 2021
Observational StudyWhen Clinicians Should Repeat RT-PCR for SARS-CoV-2: Repeat PCR Testing in Patients with Pulmonary CT Findings Suggestive of COVID-19.
Real-time reverse transcription polymerase chain reaction (RT-PCR) tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are occasionally repeated when clinicians suspect false-negative results, but the conditions under which repeated RT-PCR testing is warranted remain unclear. We evaluated the practice of repeat RT-PCR testing for SARS-CoV-2 in 45 patients who were retested after an initial negative PCR test. Of these, the diagnosis of coronavirus disease (COVID-19) was confirmed in four patients with typical chest computed tomography (CT) findings and in one patient without typical CT findings in whom the test result was strongly suspected to be false-positive. We recommend repeat RT-PCR testing only for patients with typical CT findings of COVID-19.