Performance assessment of the Capilia TB assay and the BD ProbeTec ET system for rapid culture confirmation of Mycobacterium tuberculosis.

Because of the increasing numbers of nontuberculous mycobacterial isolates from clinical specimens, rapid and accurate methods for culture confirmation of Mycobacterium tuberculosis are urgently needed. The study evaluated the performance of the Capilia TB immunochromatographic assay (TAUNS, Numazu, Japan) for culture confirmation of M. tuberculosis using 242 culture-positive liquid media in 2 mycobacterial laboratories from November 2005 to February 2006. Among the 242 samples, 183 were also tested with the BD ProbeTec ET (CTB) assay (Becton Dickinson, Sparks, MD). The results of both assays were compared to the culture results and to each other. The overall sensitivity and specificity of the Capilia TB assay were 98.6% and 97.9%, respectively, and for the CTB assay were 97.3% and 97.1%, respectively. The positive and negative predictive values for the Capilia TB assay were 98.6% and 97.9%, respectively, and for the CTB assay were 98.2% and 95.8%, respectively. Among the 183 samples tested with both assays, 8 had discrepant results, including Capilia-TB-false-positive in 2, CTB-false-positive in another 2, CTB-false-negative in 2, Capilia TB-false-negative in 1, and both assays with false-negative results in the remaining one. This study demonstrated that the Capilia TB assay has a similar diagnostic value with the CTB assay. In addition, with the immunochromatographic method, it is less time-consuming and does not require other laboratory equipment.

Assessment of Platelia Aspergillus enzyme immunoassay for the diagnosis of invasive aspergillosis.

BACKGROUND AND PURPOSE: This study investigated the diagnostic value of Platelia Aspergillus enzyme immunoassay (EIA) for galactomannan (GM) antigen in patients at risk of invasive aspergillosis (IA), and its association with clinical course and outcome. METHODS: A total of 304 blood samples were collected from 189 patients at risk of IA during a 1-year period at a tertiary referral center. Classification of IA was made on the basis of the European Organization for Research and Treatment of Cancer case definitions. RESULTS: Of the 189 patients, 5 had proven IA, 9 had probable IA, 26 had possible IA, and 149 had no IA. Diagnostic levels of GM were detected in 80% of proven and in 77% of probable IA cases. The overall sensitivity, specificity, and positive and negative predictive values for this assay, using a 1.5 index cut-off value, were 78.6%, 93.9%, 55.0%, and 97.9%, respectively. With the 0.5 index cut-off value, the sensitivity would increase to 100%. A close relationship was found between clinical course and the kinetics of GM indices in survivors. CONCLUSIONS: The Platelia Aspergillus EIA is a useful screening test for the detection of IA. Regular monitoring of the kinetics of GM-EIA indices is a useful predictor of clinical course and outcome.

Performance assessment of the DR. MTBC Screen assay and the BD ProbeTec ET system for direct detection of Mycobacterium tuberculosis in respiratory specimens.

The performance of the DR. MTBC PCR-based assay and the BD ProbeTec ET Mycobacterium tuberculosis Complex Direct Detection (DTB) assay for the direct detection of Mycobacterium tuberculosis was evaluated using 1,066 consecutive clinical respiratory samples collected from 494 patients who did not have old cases of pulmonary tuberculosis and were not receiving antituberculosis treatment at National Taiwan University Hospital from January to February 2005. The results of both assays were compared to the "gold standard" of combined culture results and clinical diagnosis. The overall sensitivity and specificity of the DR. MTBC Screen assay were 56.6% and 98.9%, respectively, and of the DTB assay were 63.2% and 98.4%, respectively. The positive and negative predictive values for the DR. MTBC Screen assay were 84.5% and 95.4%, respectively, and for the DTB assay were 81.7% and 96.0%, respectively. The DR. MTBC Screen assay produced 11 false-positive results for 11 patients, including three samples yielding non-M. tuberculosis mycobacteria (one each for M. abscessus, a mixture of M. abscessus and M. chelonae, and unidentified non-tuberculosis mycobacteria). The DTB assay produced 15 false-positive results for 13 patients, including five samples from four patients yielding non-tuberculosis mycobacteria (two for M. abscessus, one for a mixture of M. abscessus and M. chelonae, and two for unidentified non-tuberculosis mycobacteria). This study demonstrated that the DR. MTBC Screen assay has a similar diagnostic value but fewer false-positive results than the DTB assay for respiratory specimens.

Performance assessment of a nested-PCR assay (the RAPID BAP-MTB) and the BD ProbeTec ET system for detection of Mycobacterium tuberculosis in clinical specimens.

The performance of a nested PCR-based assay (the RAPID BAP-MTB; AsiaGen, Taichung, Taiwan) and the BD ProbeTec ET (DTB) system (Becton Dickinson, Sparks, Md.) for detection of Mycobacterium tuberculosis was evaluated with 600 consecutive clinical samples. These samples, including 552 respiratory specimens and 48 nonrespiratory specimens, were collected from 333 patients treated at National Taiwan University Hospital from September to October 2003. The results of both assays were compared to the gold standard of combined culture results and clinical diagnosis. The overall sensitivity and specificity of the RAPID BAP-MTB assay for respiratory specimens were 66.7% and 97.2%, respectively, and for the DTB assay they were 56.7% and 95.3%, respectively. The positive and negative predictive values for the RAPID BAP-MTB were 74.1% and 96.0%, respectively, and for the DTB assay they were 59.6% and 94.7%, respectively. For smear-negative samples, the sensitivity of the RAPID BAP-MTB and DTB assays was 57.1% and 40.5%, respectively. The RAPID BAP-MTB assay produced 14 false-positive results in 14 samples, including one of the six samples yielding Mycobacterium abscessus, one of the six samples yielding Mycobacterium avium intracellulare, one sample from a patient with a history of pulmonary tuberculosis with complete treatment, and three samples from three patients with a previous diagnosis of tuberculosis who were under treatment at the time of specimen collection. Among the 48 nonrespiratory specimens, the RAPID BAP-MTB assay was positive in one biopsy sample from a patient with lumbar tuberculous spondylitis and one pus sample from a patient with tuberculous cervical lymphadenopathy. Our results showed that the RAPID BAP-MTB assay is better than the DTB assay for both respiratory specimens and nonrespiratory specimens. The overall time for processing this assay is only 5 h. In addition, its diagnostic accuracy in smear-negative samples is as high as in smear-positive samples.

Implications of nursing care in the occurrence and consequences of unplanned extubation in adult intensive care units.

This 18-month study used a structured questionnaire to explore the roles of nursing care on the occurrence and consequences of unplanned endotracheal extubation (UEE) in intensive care units in Taiwan. Experiencing UEE were 225/1176 (22.5%) intubated patients: 91.7% were self-extubations and 8.3% were accidental. Self-extubations occurred most frequently during night shifts and in the care of nurses with less working experience. Accidental extubations occurred most frequently in patients undergoing routine nursing procedures, usually required immediate re-intubation and were associated with more complications. An appropriate nurse-to-patient ratio, better working procedures and continual nursing education programs might help reduce occurrence and complications of UEE.