Abstract
The Luminex xTAG Respiratory Virus Panel (RVP) assay has been shown to offer improved diagnostic sensitivity over traditional viral culture methods and to have a sensitivity comparable to those of individual real-time nucleic acid tests for respiratory viruses. The objective of this retrospective study was to test a new, streamlined version of this assay, the RVP Fast assay, which requires considerably less run time and operator involvement. The study compared the performance of the RVP Fast assay with those of viral culture, a direct fluorescent assay (DFA), and a panel of single and multiplex real-time PCRs in the testing of 286 respiratory specimens submitted to the Edinburgh Specialist Virology Centre for routine diagnosis of viral infection between December 2007 and February 2009. At least one respiratory viral infection was detected in 13.6% of specimens by culture and DFA combined, in 49.7% by real-time PCR, and in 46.2% by the RVP Fast assay. The sensitivity and specificity of the RVP Fast assay compared to the results of real-time PCR as the gold standard were 78.8% and 99.6%, respectively. Real-time PCR-positive specimens missed by the RVP Fast assay generally had low viral loads or were positive for adenovirus. Additionally, a small number of specimens were positive by the RVP Fast assay but were not detected by real-time PCR. For some viral targets, only a small number of positive results were found in our sample set using either method; therefore, the sensitivity of detection of the RVP Fast assay for individual targets could be investigated further with a greater number of virus-positive specimens.