[Assessment of viral gastroenteritis diagnosis using an immunochromatography-based method]

We evaluated the norovirus (NoV) detection reagent kit, which uses immunochromatography (IC), against outbreaks of food-borne acute viral gastroenteritis having occurred in Osaka Prefecture between November 2008 and March 2009. A total of 33 outbreaks, RT-PCR identified 27 NoV-positive cases, whereas the IC kit identified 26 cases. Out of 103 specimens positive for NoV using RT-PCR, the IC kit identified 68 positive cases, with a positive conformity ratio of 66%. The mean copy number of NoV was approximately 10(7.1) per 10 mg feces for IC kit positive samples, and approximately 105(5.8) per 10 mg for negative samples. Although the NoV genogroup (G) II/4 was associated with 18 outbreaks and a total of 8 different genotypes were identified in NoV positive samples, G I/7 was not detected using the IC kit. Our results suggest that the IC kit, which detected 96% of the outbreaks of food-borne acute viral gastroenteritis by NoV, facilitates the diagnosis of outbreaks.