Etiological identification and phylogenetic analysis of a clustered epidemic caused by norovirus on a patrol boat

ObjectiveTo determine the pathogen and phylogenetic characteristics of an uncommon outbreak of recombinant norovirus infection in Daishan County in February 2022.MethodsFluorescence quantitative PCR was used to detect the norovirus in the eight anal swabs collected in the outbreak. In the positive samples， reverse transcription PCR were used to amplify the norovirus. Norovirus sequences were characterized by MEGA7 and Simplot.ResultsNorovirus GⅠ was identified in all eight anal samples. It was further determined to be recombinant norovirus GⅠ.6 ［P11］， with the recombination site at the ORF1-ORF2 junction. The sequence had the highest nucleotide identity （98.75%） to a GⅠ.6［P11］ strain collected in 2018 （GenBank accession number MT357995）.ConclusionAccording to the etiological identification and phylogenetic analysis， this outbreak is confirmed to be caused by the uncommon recombinant norovirus GⅠ.6 ［P11］ in China.