Verification of a Novel Multiplex PCR Respiratory Virus Panel in a US Biocontainment Unit

Abstract

Emerging infectious diseases carry unique logistical, financial, and clinical ramifications. Rapid diagnostic testing methods can alleviate some of these challenges by providing definitive diagnoses earlier in the clinical course, leading to appropriate targeted therapy, cost savings, and improved patient outcomes. The BioFire FilmArray Respiratory Panel 2 plus (RP2plus; bioMérieux, Marcy l’Etoile, France) is a multiplexed nucleic acid test for detection of Middle East respiratory syndrome coronavirus (MERS-CoV) and 14 common viral and 4 bacterial respiratory pathogens in nasopharyngeal swabs obtained from those meeting MERS-CoV epidemiological criteria. The aim of this study was to verify the FilmArray RP2plus for use in our biocontainment unit. Of note, the RP2plus is FDA approved but not currently available for sale in the United States. Eight patient samples were tested with known results (GenMark Respiratory Virus Panel [RVP] or Cepheid Xpert Flu/RSV). We had concordant results between the platforms for samples containing influenza A, respiratory syncytial virus (RSV), parainfluenza virus 2, rhinovirus, and a negative sample. We evaluated two influenza B samples from two different patients. The FilmArray RP2plus did not detect influenza B in one of the patient samples. The sample was exhausted and repeat testing could not be performed. A second rhinovirus sample was not detected by the RP2plus, but Coronavirus 229E was detected in this sample, a virus not detected by the RVP. The sample was repeated and again did not detect rhinovirus. Further investigation into this discrepancy revealed that rhinovirus was originally detected by RVP at a signal of 34.4 nA (repeat of 46.9 nA). The concordant rhinovirus sample had a signal of 226.7 nA by RVP, which was much higher than the discrepant sample. Because of the low signal by RVP in the discrepant sample, perhaps the viral load was below the limit of detection of the RP2plus. All other quality control sample pools passed verification testing, including day-to-day and operator variance. It is not uncommon for a person under investigation (PUI) for a highly communicable disease to be evaluated in our facility. The performance of the RP2plus test on clinical samples showed acceptable concordance with our current means of testing for respiratory pathogens. The RP2plus will eliminate challenges implicated in storing and transporting specimens to an off-site lab, facilitate quicker turnaround time, and streamline the often cumbersome, complex protocols and practices required to work up a serious communicable disease.