Evaluation of 4 immunochromatographic tests for rapid detection of norovirus in faecal samples

BackgroundThe rapid detection of noroviruses is essential to implement measures to reduce the rapid spread of gastroenteritis infections they cause, notably in institutions.ObjectivesTo evaluate 4 rapid immunochromatographic tests: RIDA®QUICK Norovirus, ImmunoCardSTAT!® Norovirus, NOROTOP® and SD BIOLINE NOROVIRUS by determining their sensitivity and specificity on a large panel of samples representing 11 genotypes of norovirus genogroup I and 14 of genogroup II, and their cross-reactivity with other enteric viruses.Study designThawed stool samples containing norovirus genogroup I or II or other enteric viruses, and negative samples, were tested by the 4 assays and compared to the reference standard RT-PCR. Fresh stool samples were also tested by RIDA®QUICK.ResultsThe sensitivity of RIDA®QUICK, ImmunoCardSTAT!®, NOROTOP® and SD BIOLINE for the detection of norovirus genogroup I on thawed samples was 17%, 26%, 52% and 23%, respectively. For genogroup II, the sensitivity was 64%, 39%, 50% and 54%, respectively. For GII.4, the main circulating genotype, the sensitivity was 78%, 59%, 61% and 67%, respectively. For all tests, the specificity was 100% and no cross-reactivity with other enteric viruses was observed. The sensitivity of RIDA®QUICK on fresh stool samples positive for GII.4 was 71%.ConclusionsKnowing that most gastroenteritis cases are due to GII.4, the immunochromatographic tests may be useful for preliminary screening, notably in outbreaks. However, negative samples need to be tested using RT-PCR methods.