Diagnosis and antibiotic treatment of group a streptococcal pharyngitis in children in a primary care setting: impact of point-of-care polymerase chain reaction.

BACKGROUND: To compare the sensitivity and specificity of the recommended 2-step rapid antigen detection test (RADT) with confirmatory culture vs the point-of-care (POC) polymerase chain reaction (PCR) Roche cobas® Liat® Strep A test for detection of group A Streptococcus (GAS) in pediatric patients with pharyngitis, and to investigate the impact of these tests on antibiotic use in a large pediatric clinic. METHODS: This prospective, open-label study was conducted at a single site during fall/winter 2016-2017. A total of 275 patients aged 3 to 18 years with symptoms of pharyngitis had a throat-swab specimen analyzed using RADT, POC PCR, and culture. The sensitivity, specificity, and percentage agreement (95% CI) between assays and a laboratory-based nucleic acid amplification test were calculated. DNA sequencing was used to adjudicate discrepancies. The RADT or POC PCR result was provided to clinicians on alternating weeks to compare the impact on antibiotic use. RESULTS: A total of 255 samples were evaluated; 110 (43.1%) were GAS positive. Sensitivities (95% CI) for POC PCR, RADT, and culture were 95.5% (89.7-98.5%), 85.5% (77.5-1.5%), and 71.8% (62.4-80.0%), respectively. Specificities (95% CI) for POC PCR, RADT, and culture were 99.3% (96.2-99.98%), 93.7% (88.5-97.1%), and 100% (97.5-100%), respectively. Compared with RADT, POC PCR resulted in significantly greater appropriate antibiotic use (97.1% vs 87.5%; P = .0065). CONCLUSION: Under real-world conditions, RADT results were less specific and culture results were less sensitive than found in established literature and led to increased rates of inappropriate antibiotic use. POC PCR had high sensitivity and specificity and rapid turnaround times, and led to more appropriate antibiotic use. TRIAL REGISTRATION: ID number ISRCTN84562679 . Registered October 162,018, retrospectively registered.

HCV RNA detection in HCV antibody-positive patients with the COBAS AmpliPrep/COBAS TaqMan HCV test, v2.0 in comparison with FDA-approved nucleic acid tests.

BACKGROUND: Analysis of hepatitis C virus (HCV) RNA levels is critical for assessing the efficacy of antiviral therapy and the achievement of a sustained virologic response. OBJECTIVE AND STUDY DESIGN: This study evaluated the clinical performance of the COBAS AmpliPrep/COBAS TaqMan HCV quantitative test, version 2.0 (TAQMAN v2.0) with the COBAS AmpliPrep/COBAS TaqMan HCV quantitative test, version 1.0 (TAQMAN v1.0), the VERSANT HCV qualitative assay (VERSANT), and the COBAS AMPLICOR HCV test, v2.0 (AMPLICOR) qualitative test for the detection of HCV RNA in serum or EDTA plasma from patients who are or have been infected with HCV and carry HCV antibodies. RESULTS: A total of 277 participants were evaluable for the percent agreement analysis of the TAQMAN v2.0 with the VERSANT and with the AMPLICOR. The overall percent agreement between the TAQMAN v2.0 and the VERSANT or the AMPLICOR was 99.3% (95% CI: 97.4%, 99.8%) or 98.9% (95% CI: 96.9%, 99.6%), respectively. The overall percent agreement between the TAQMAN v2.0 and the TAQMAN v1.0 when 267 of the original samples were assessed was 98.9% (95% CI=96.7%, 99.6%). CONCLUSION: The TAQMAN v2.0 demonstrated high correlation with the previously approved HCV RNA quantitative and qualitative tests.