The Norovirus ELISA is used for direct detection of Norovirus specific antigens in stool specimens.
One kit is designed for 1x 96 determinations. The expiry date of each component is reported on its respective label, that of the complete kit on the outer box label.
Upon receipt, all test components have to be kept at 2°C - 8°C , preferably in the original kit box. After opening all kit components are stable for at least 2 months, provided proper storage.
The ready to use wash solution can be used for at least one month when stored at 2°C - 8°C .
Intra-assay Precision: 2.00%-5.92%
Inter-assay Precision: 2.76%-7.59%
The lower detection limit of the Norovirus ELISA was determined < 10 ng/mL capsid protein for genogroup I and II.
Noroviruses belong to the family Caliciviridae, single stranded RNA viruses of 30 - 40 nm in size characterized by a typical cup-shaped capsid. Within the genus Norovirus the two human pathogenic genogroups GGI and GGII have been identified. GGI and GGII strains can be further sub-classified into at least 15 and 18 genotypes resp. The genetic heterogeneity of Noroviruses causes distinct capsid protein divergences between different genogroups (about 60%) as well as between different genotypes within one genogroup (about 20 - 30%). Since 1994 genotype GGII.4 is predominantly circulating. Noroviruses are very resistant to environmental conditions and highly contagious.
The infection is transmitted by direct contact to already infected people either by faecal-oral transmission or by ingestion of aerosols from vomit or by contaminated food, drinking water or objects. After a short, 10 - 50 hours lasting incubation time fulminant diarrhoea and often vomiting develop as the characteristic symptoms. The infection is usually self-limiting and symptoms disappear after 2 - 3 days. Norovirus infections are characterized by seasonal fluctuations with a climax during the winter months. They are considered as the most common cause of non-bacterial gastroenteritis outbreaks worldwide, but may also be responsible for single cases of viral gastroenteritis. The high sequence variability of the capsid proteins circumvents the production of protective antibodies and hampers diagnostic detection. Methods like PCR (usually as "Real time Reverse Transcriptase PCR–Rt RT-PCR) and enzyme immunoassay are commonly used for laboratory diagnosis.