Evaluation of the RIDAQuick norovirus immunochromatographic test kit

Background: Norovirus infections occur frequently and are widespread throughout the US population causing greater than half of all foodborne gastroenteritis cases. A rapid norovirus assay would be a useful clinical tool for identification of this common virus in gastroenteritis patient samples, thereby identifying outbreaks and facilitating rapid implementation of control measures.

Objectives: To determine the suitability of the RIDAQuick norovirus kit as a clinical tool by determining the specificity and sensitivity of the assay, and its cross-reactivity with other enteric viruses.

Study design: Archived stool specimens containing norovirus genogroup I or II or other viruses were tested using the RIDAQuick norovirus assay and results compared to those obtained with real-time RT-PCR.

Results: We tested 62 samples: 19 norovirus genogroup I, 25 genogroup II samples, and 18 norovirus negative samples. Compared to PCR results, RIDAQuick assay sensitivity was 61.4%, and specificity was 100%. The low sensitivity was mainly due to poor results with genogroup I specimens; only 11 of 19 were detected. Additionally, samples of four other common enteric viruses all tested negative with the RIDAQuick assay.

Conclusions: The RIDAQuick kit effectively detects norovirus genogroup II strains, but not genogroup I strains. We found no cross-reactivity with several common enteric viruses. As most norovirus cases are currently genogroup II strains, positive results with RIDAQuick can be used for rapid detection of norovirus in a large percentage of cases, thus also aiding in identification of outbreaks. However, final confirmation and negative results require further testing with more sensitive methods.