Commercial Nucleic-Acid Amplification Tests for Diagnosis of Pulmonary Tuberculosis in Respiratory Specimens: Meta-Analysis and Meta-Regression

BACKGROUND: Hundreds of studies have evaluated the diagnostic accuracy of nucleic-acid amplification tests (NAATs) for tuberculosis (TB). Commercial tests have been shown to give more consistent results than in-house assays. Previous meta-analyses have found high specificity but low and highly variable estimates of sensitivity. However, reasons for variability in study results have not been adequately explored. We performed a meta-analysis on the accuracy of commercial NAATs to diagnose pulmonary TB and meta-regression to identify factors that are associated with higher accuracy. METHODOLOGY/PRINCIPAL FINDINGS: We identified 2948 citations from searching the literature. We found 402 articles that met our eligibility criteria. In the final analysis, 125 separate studies from 105 articles that reported NAAT results from respiratory specimens were included. The pooled sensitivity was 0.85 (range 0.36-1.00) and the pooled specificity was 0.97 (range 0.54-1.00). However, both measures were significantly heterogeneous (p<.001). We performed subgroup and meta-regression analyses to identify sources of heterogeneity. Even after stratifying by type of commercial test, we could not account for the variability. In the meta-regression, the threshold effect was significant (p = .01) and the use of other respiratory specimens besides sputum was associated with higher accuracy. CONCLUSIONS/SIGNIFICANCE: The sensitivity and specificity estimates for commercial NAATs in respiratory specimens were highly variable, with sensitivity lower and more inconsistent than specificity. Thus, summary measures of diagnostic accuracy are not clinically meaningful. The use of different cut-off values and the use of specimens other than sputum could explain some of the observed heterogeneity. Based on these observations, commercial NAATs alone cannot be recommended to replace conventional tests for diagnosing pulmonary TB. Improvements in diagnostic accuracy, particularly sensitivity, need to be made in order for this expensive technology to be worthwhile and beneficial in low-resource countries

Screening to select patients carrying extended-spectrum β-lactamase-producing Enterobacteriaceae for isolation in Flemish intensive care units: a Swiss cheese strategy?,Screening to select patients carrying extended-spectrum beta-lactamase-producing Enterobacteriaceae for isolation in Flemish intensive care units : a Swiss cheese strategy?

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False-Positive Results by the Platelia Aspergillus Galactomannan Antigen Test for Patients Treated with Amoxicillin-Clavulanate▿

The Aspergillus galactomannan test is a valuable tool in the diagnosis of invasive aspergillosis. We hereby report a high rate of false-positive results by the Platelia Aspergillus galactomannan antigen test (Bio-Rad Laboratories) for patients treated with amoxicillin-clavulanate

The Clinical Impact of Rapid Molecular Microbiological Diagnostics for Pathogen and Resistance Gene Identification in Patients With Sepsis: A Systematic Review

Contains fulltext : 229512.pdf (publisher's version ) (Open Access)Fast microbiological diagnostics (MDx) are needed to ensure early targeted antimicrobial treatment in sepsis. This systematic review focuses on the impact on antimicrobial management and patient outcomes of MDx for pathogen and resistance gene identification compared with blood cultures. PubMed was searched for clinical studies using either whole blood directly or after short-term incubation. Twenty-five articles were retrieved describing the outcomes of 8 different MDx. Three interventional studies showed a significant increase in appropriateness of antimicrobial therapy and a nonsignificant change in time to appropriate therapy. Impact on mortality was conflicting. Length of stay was significantly lower in 2 studies. A significant decrease in antimicrobial cost was demonstrated in 6 studies. The limitations of this systematic review include the low number and observed heterogeneity of clinical studies. In conclusion, potential benefits of MDx regarding antimicrobial management and some patient outcomes were reported. More rigorous intervention studies are needed focusing on the direct benefits for patients

Comparison and Evaluation of Osiris and Sirscan 2000 Antimicrobial Susceptibility Systems in the Clinical Microbiology Laboratory

The Osiris and Sirscan 2000 systems are two semiautomated systems that can be used to read and interpret the results on disk diffusion agar plates. They are both used for determination of susceptibility to antimicrobial agents. The present study compared both systems versus the NCCLS standard method of visual reading with a ruler. Both inpatient and outpatient samples with a total of 315 nonfastidious gram-negative strains were obtained. In total, 3,724 organism-antimicrobial agent combinations that fulfilled the NCCLS guidelines for disk diffusion susceptibility testing were evaluated prospectively. The results obtained with both systems in comparison with those obtained by the classical nonautomated means of interpretation were excellent, with correlation coefficients of 0.96 for both systems. The overall agreements for susceptibility interpretation were 96.56 and 96.24% with the Osiris and Sirscan systems, respectively. Very major errors were obtained for 8 (1.07%) and 10 (1.34%) organism-antimicrobial agent combinations with the Osiris and Sirscan systems, respectively. In addition, major errors were obtained for 2 (0.07%) and 6 (0.21%) combinations with the Osiris and Sirscan systems, respectively. Minor errors were obtained for 118 and 124 organism-antimicrobial agent combinations with the Osiris and Sirscan systems, respectively. Overall, both the Osiris system and the Sirscan system are comparable and reliable systems for determination of interpretative categories from the zone diameters of standard disk diffusion test plates

Invasive fungal infection in an elderly patient with defective inflammatory macrophage function

Macrophages are known to be involved in pathogen recognition and mediate host immune responses, but, in the clinical setting, their purported central role in opportunistic fungal infections has not been demonstrated to date. Herein, we describe a patient with invasive testicular aspergillosis in whom we found, for the first time, a defect in macrophage function

Antibiotic prophylaxis in TURP: a prospective analysis concerning antibiotic stewardship and a potential reduction of antibiotic use in TURP

PURPOSE: Antibiotic prophylaxis is standard procedure in transurethral resection of the prostate (TURP). We evaluated the necessity of antibiotic (AB) prophylaxis in TURP due to increasing microbial antibiotic resistance. METHODS: This is a prospective cohort study of 506 patients. Only patients with a pre-operative catheter/pyuria received AB-prophylaxis. Urine analysis (pre-operative, at discharge, and 3 week post-operative) was performed next to an analysis of the blood culture/irrigation fluid and of the resected prostatic tissue. Statistical analysis was performed using Fisher's exact test. RESULTS: 67/506 (13.2%) patients received prophylactic antibiotics. 56/67 (83.5%) patients had a pre-operative catheter and 11/67 (16.4%) had pre-operative pyuria in which a fluoroquinolone-resistance (FQ-R) rate of 69.2% in Escherichia coli (EC) was observed. Clinical infectious symptoms were present in 13/439 (2.9%) patients without antibiotic prophylaxis; 12/439 (2.7%) patients had uncomplicated fever ( 38.5°) observed. Uncomplicated fever developed in 7/67 (10.4%) patients who did receive AB-prophylaxis. FQ-R was observed in 60% of the positive urine cultures at discharge and in 53.8% 3 week post-operatively. CONCLUSIONS: Our data show a low infectious complication rate (2.9%) in patients without a pre-operative catheter or pyuria,undergoing TURP without AB-prophylaxis. These findings might question the current use of AB prophylaxis in TURP in patients without a pre-operative catheter or pyuria, in times of antibiotic stewardship due to the high rate of microbial-resistance in our population.status: publishe