Clinical evaluation of a bioluminescent enzyme immunoassay for detecting norovirus in fecal specimens from patients with acute gastroenteritis

Noroviruses (NoVs), which belong to the family Caliciviridae, are major causative agents of acute gastroenteritis worldwide. Thus, rapid and highly sensitive assays for detecting NoVs are required. Recently, a bioluminescent enzyme immunoassay (BLEIA) for detecting NoVs in fecal specimens was developed. This new assay was evaluated using fecal specimens obtained from acute gastroenteritis patients. Of the 107 specimens that were found to be NoV-positive by RT-PCR or RT-LAMP, 104 specimens produced positive results in the BLEIA (sensitivity: 96.3%). On the other hand, no false-positive results were observed during the testing of 176 NoV-negative specimens containing group A or C rotaviruses, astroviruses, sapoviruses, adenovirus type 41, bocaviruses, or parechoviruses. Furthermore, the BLEIA was able to detect many NoV genotypes in the tested specimens, including three genotypes from genogroup I (genotypes 1, 4, and 8) and ten genotypes belonging to genogroup II (genotypes 1, 2, 3, 4, 5, 6, 12, 13, 16, and 19). By quantifying the number of NoV genome copies in the clinical specimens tested with the BLEIA, its detection limit was estimated to be 10(6) genome copies per gram of stool and below. Furthermore, as the BLEIA can be performed with an automated device and does not involve complicated procedures it can be used to rapidly test many samples. Therefore, the BLEIA is a rapid and highly sensitive method and could be used as a diagnostic tool at hospitals and clinical laboratories that deal with large numbers of clinical specimens from acute gastroenteritis patients or food handlers. J. Med. Virol. 86:1219-1225, 2014.