Performance Evaluation of a Novel Fully Automated Real-Time Reverse Transcriptase-Polymerase Chain Reaction Kit for the Detection of Norovirus.

Objective: Rapid and accurate detection of norovirus is essential for the prevention and control of the out- breaks. The aim of this study is to compare the fully automated real-time reverse transcriptase-polymerase chain reaction method (EV-kit) with the conventional immunochromatography method (IC) for diagnosis of norovirus, using one-tube reverse transcriptase-polymerase chain reaction (RT-PCR) analysis as the gold standard.

Methods: Between November 2013 and March 2014, clinical data and fecal specimens (53 bulk stools, 41 rectal swabs) were collected from 94 patients who visited the Department of General Medicine, Juntendo University Hospital for acute diarrhea. The sensitivity and specificity of each study test was determined by comparing with RT-PCR, and reproducibility was analyzed by determining Cohen's kappa coefficients.

Results: Of 94 specimens, 35(37%, 26 bulk stools, 9 rectal swabs) were positive for norovirus antigen by RT-PCR. The sensitivity, specificity, and Cohen's kappa coefficient of the EV-kit were 91% (32/35), 88% (52/59), and 0.778, respectively; those of the IC were 54% (19/35), 90% (53/59), and 0.468, respectively. For rectal swab testing, the sensitivity was 89% (8/9) for the EV-kit and 33% (3/9) for IC, ana that for bulk stool testing was 92% (24/26) for the EV-kit and 62% (16/26) for IC.

Conclusions: Use of the EV-kit was significantly more sensitive than was IC testing, taking RT-PCR analy- sis as the gold standard. Rectal swab or bulk stool specimens may be adequate for the detection of norovirus antigen when the EV-kit is used. [Original].