The novel norovirus genotype GII.17 is the predominant strain in diarrheal patients in Shanghai, China

In the winter of 2014–2015, a novel norovirus (NoV) strain (GII.17) was reported to be the major cause of gastroenteritis outbreaks in East Asia. To determine the time course of gastroenteritis infections associated with the GII.17 strain and whether GII.17 was the main epidemic strain in diarrheal patients in Shanghai, 2169 stool samples were collected and tested. The detection rate of NoV GI and GII NoV strains was 0.83 and 24.02%, respectively. Phylogenetic analysis confirmed that there were seven NoV genotypes, among which GII.4 and GII.17 were the main genotypes. The GII.17 strain was first detected in a sample collected on August 14th, 2014, and beginning in January 2015, the novel GII.17 strain replaced the GII.4 strain as the dominant NoV genotype causing acute gastroenteritis in patients in Shanghai.