Detection of human norovirus GIV.1 in China: a case report

Noroviruses (NoVs) are a common cause of acute gastroenteritis (AGE) around the world; however, reports of genogroup IV (GIV) NoVs are rare. Here we report a human GIV genotype 1 (GIV.1) NoV strain (named CHNNGIV2011) identified by 454 high-throughput sequencing from stool samples of children with diarrhea. This is the first documented human GIV.1 NoVs infection in China. The complete genome of the virus is 7525 nucleotides in length. Sequencing and phylogenetic analyses showed that CHNNGIV2011 shared high sequence similarity to other GIV.1 NoVs from all over the world, especially to the recently reported NoV GIV.1 strain Lake Macquarie genome (99.0%). By seminested PCR and real-time PCR, a total of 2 out of 466 samples were positive for GIV.1 CHNNGIV2011 in Lulong County, Hebei Province, China, which supported a low prevalence of GIV.1 NoVs. The positive samples contained 7.2×10(7) and 2.6×10(8)copies/g in feces. In addition, one positive sample was found coinfection with strains NoV GII and salivirus. These findings suggest more study is needed to address the worldwide prevalence and role of GIV NoVs in AGE.