Performance of the Abbott RealTime and Roche Cobas TaqMan hepatitis C virus (HCV) assays for quantification of HCV genotypes.

We evaluated the Abbott RealTime (ART) and Roche Cobas TaqMan Hepatitis C virus (HCV) viral load assays for quantification of HCV genotypes in patient specimens. The ART HCV assay was a more sensitive and precise tool for accurate HCV viral load quantification across the HCV genotypes tested, especially genotype 1b.

Detection of yeasts in blood cultures by the Luminex xTAG fungal assay.

A multiplex-PCR Luminex xMAP bead probe fluid array using xTAG analyte-specific reagents (multiplex xTAG fungal ASR assay) was employed for detection of clinically significant Candida species, Cryptococcus neoformans, Histoplasma capsulatum, and Blastomyces dermatitidis from blood cultures. We tested 132 blood cultures negative (n = 10) or positive (n = 97) for yeasts and/or bacteria (n = 25). The assay showed sensitivity and specificity of 100% and 99%, respectively. The xTAG fungal ASR assay is a rapid assay that allows simultaneous identification of multiple yeast species.

Evaluation of commercial ResPlex II v2.0, MultiCode-PLx, and xTAG respiratory viral panels for the diagnosis of respiratory viral infections in adults.

BACKGROUND: Commercial multiplex PCR panels for respiratory viruses (PRV) have been recently developed. ResPlex II Panel v2.0 (Qiagen), MultiCode-PLx (EraGen Biosciences), and xTAG (Luminex) PRV's were studied. All assays detect influenza A and B, adenovirus, parainfluenza 1-3, respiratory syncytial virus A and B, human metapneumovirus and human rhinovirus. The ResPlex II additionally detects coronavirus (229E, OC43, NL63, HKU1), coxsackie/echo virus, bocavirus and differentiates adenoviruses (B, E). The MultiCode-PLX assay detects 229E, OC43, and NL63, differentiates parainfluenza 4a, 4b and adenoviruses (B, C, E). The xTAG additionally subtypes influenza A as seasonal H1 and H3. STUDY DESIGN: 202 specimens collected from adult patients with signs of respiratory infection from November, 2008 to May, 2009 were used for evaluating the performance of the three commercial PRV assays. Viral culture and xTAG were used as the standards to assess sensitivity and specificity. RESULTS: The PRV assays detected more viruses than culture. When compared to culture, the xTAG PRV showed a sensitivity and specificity of 100% and 91%, compared to MultiCode-PLx with 89% and 87%, and ResPlex II with 89% and 94%, respectively. Co-infection was detected in a small subset of patient specimens. Each panel showed differences in sensitivities for individual viruses. CONCLUSIONS: While the ResPlex II and MultiCode-PLx offer a broader virus detection range and greater ease of use, the xTAG PRV showed increased sensitivity to common viral targets represented in the assays, and also had the ability to differentiate human from non-human influenza A H1.