Evaluation of Immunochromatographic Tests and a New Enzyme Immunoassay for Detection of a Novel GII.17 Norovirus in Stool Samples.

A novel GII.17 norovirus (NoV), Kawasaki 2014, has spread to several regions of the world. Rapid and reliable diagnostic tests are needed for the detection of this new NoV variant. In this study,analytical sensitivity of 7 different immunochromatographic (IC) test kits (6 are on the market in Japan and one in Europe) was evaluated by means of confirmed GII.17 NoV-positive stool samples. The stool samples were also tested by a bioluminescent enzyme immunoassay (BLEIA). Real-time RT-PCR served as a reference (gold standard) method. Among the 7 IC kits, RIDA QUICK was the most sensitive, with the limit of detection of 10 copies/ml, whereas the limits of detection of the other IC kits ranged from 10 to 10 copies/ml. It should be pointed out that the limit of detection of BLEIA was approximately 100- to 1,000-fold better (10-10 copies/ml) than that of RIDA QUICK. Nevertheless, the procedure of BLEIA took more time and required sophisticated equipment.