Emergence of Norovirus GII.17-associated Outbreak and Sporadic Cases in Korea from 2014 to 2015

Abstract

Human norovirus are major causative agent of nonbacterial acute gastroenteritis. In general, genogroup (G) II.4 is the most prominent major genotype that circulate in human population and the environment. However, a shift in genotypic trends was observed in Korea in December 2014. In this study, we investigated the trend of norovirus genotype in detail using the database of Acute Diarrhea Laboratory Surveillance (K-EnterNet) in Korea. GII.17 has since become a major contributor to outbreaks of norovirus-related infections and sporadic cases in Korea, although the reason for this shift remain unknown.

Epidemiology of Norovirus Outbreaks Reported to the Public Health Emergency Event Surveillance System, China, 2014–2017

“…From December 2016 to May 2017, the peak of reported norovirus outbreaks was very likely associated with the emerging genotype GII.P16-GII.2 [32]. These observations are consistent with data from other countries, particularly in Asia, where in the winter of 2014, GII.17 became the predominant genotype [33,34,35,36], and in the winter of 2016, GII.P16-GII.2 emerged in China and elsewhere [31,37,38,39,40].…”

Phylogenetic characterization of norovirus strains detected from sporadic gastroenteritis in Seoul during 2014–2016

“…In the GII.17 phylogenetic tree, the first occurrence was detected as GII.17|Kawasaki323 (AB983218) in July 2014, which was identical to the new GII.P17-GII.17 reported in March 2014 in Japan [ 19 ]. The new GII.17 was 96% homologous in the amino acid sequences with the GII.17 strain reported in Korea by KCDC [ 20 ]. Since first emergence of GII.17|Kawasaki323, GII.17|CUHK-NS-616 and GII.17|Kawasaki308 sharply increased during the winter in 2014–2015, and the GII.17 became the first dominant genotype in Seoul in January 2015 (Figs.…”

“…This epidemicity was well accordant with the global trend of the new GII.17 (GII.17|Kawasaki). According to the previous report by KCDC, the GII.17, previously considered as a minor type in Korea, is the predominant NoV since December 2014 [ 20 ]. During the winter in 2014–2015, the new GII.17 also emerged and became the predominant genotype in Japan [ 19 ], several major cities in mainland China [ 21 , 22 ], and HongKong [ 23 ].…”