Norovirus GII.P16/GII.2-Associated Gastroenteritis, China, 2016

Abstract

During October-December 2016, the number of norovirus outbreaks in China increased sharply from the same period during the previous 4 years. We identified a recombinant norovirus strain, GII.P16-GII.2, as the cause of 44 (79%) of the 56 outbreaks, signaling that this strain could replace the predominant GII.4 viruses.

Keywords: China; GII.P16/GII.2; enteric infections; gastroenteritis; norovirus; recombinant; viruses.

Figure 1

Norovirus outbreaks, China. A) Outbreaks reported to the China Centers for Disease Control and Prevention during 2012–2016. B) Genotype (capsid) distribution of norovirus outbreaks during April 2014—December 2016.

Figure 2

Phylogenetic analyses of the newly identified GII.2 noroviruses in China, reconstructed based on RNA-dependent RNA polymerase (A) and open reading frame 2 (B) with a representative norovirus using the neighbor-joining method with datasets of 1,000 replicates in MEGA 6.0 software (http://www.megasoftware.net). Triangles indicates the positions of the GII.2 norovirus newly identified in 8 cities from 7 provinces. Scale bars indicate nucleotide substitutions per site.