Emergence of Norovirus GII.17 Variants among Children with Acute Gastroenteritis in South Korea

Abstract

Of 1,050 fecal specimens collected from January 2013 to August 2015 from children with acute gastroenteritis, 149 (14.2%) were found to be positive for norovirus. Norovirus GII was the most predominant genogroup (98.65%; 147 of 149). The genotypes detected in this study were GI (2; 1.3%), GII.Pe-GII.4 (109; 73.1%), GII.P17-GII.17 (16; 10.7%), GII.P12-GII.3 (8; 5.4%), GII.P12-GII.12 (8; 5.4%), GII.P4-GII.4 (5; 3.4%), and the recombinant GII.Pe-GII.17 (1; 0.7%). Of these, the novel GII.17 strain was the second most predominant, and the number of affected children appeared to continuously increase over time (2013 [2; 4.4%], 2014 [4; 9.3%], and 2015 [10; 16.4%]). Phylogenetic analysis of the full genome and ORF1, ORF2, and ORF3 nucleotide sequences showed that GII.17 was grouped in cluster III with other strains isolated from 2013 to 2015 and had a different evolutionary history from strains collected in 1978 to 2002 and 2005 to 2009 formed clusters I and II. However, the phylogenetic trees also showed that cluster III was divided into subclusters IIIa (CAU-55 and CAU-85) and IIIb (Kawasaki 2014) (CAU-193, CAU-265, CAU-267, CAU-283, and CAU-289). Comparative analysis of the VP1 capsid protein using 15 complete amino acid sequences from noroviruses isolated from 1978 to 2015 showed 99 amino acid changes. These results could be helpful for epidemiological studies to understand circulating norovirus genotypes in population.

Genetic Diversity and Epidemiology of Genogroup II Noroviruses in Children with Acute Sporadic Gastroenteritis in Shanghai, China, 2012-2017

“…RdRp/capsid genotypes were determined and that 12 of them were distinct in RdRp genotypes and capsid genotypes. All of the discordant RdRp/capsid genotypes were suspected to be recombinant strains, and most of them have been reported elsewhere [14,16,17,23,37,41]. Although more analysis of the junction of ORF1 and ORF2 is needed to confirm the recombination site in our study, the results clearly suggest that this phenomenon is very common in NoVs, as observed elsewhere.…”

Molecular Evidence of Oysters as Vehicle of Norovirus GII.P17-GII.17

“…Furthermore, PCR and sequencing of the long fragment covering the ORF1–ORF2 junction were successful in 2 samples, both genotyping as GII.P17-GII.17. Sequences had high homology (99.91%) to several Asian strains, such as Hu/GII.P17_GII.17/KR/2014/CAU-265 ( 6 ). …”

Norovirus GII.17: The Emergence and Global Prevalence of a Novel Variant

“…In the past decades, NoV GII.4 was identified as the most predominant genotype involved in numerous epidemic outbreaks, for example, in 2002,2004,2006,2009 and 2012 [37]. Recently, a novel NoV GII.17 variant has emerged and is responsible for multiple disease outbreaks mainly in China and Japan [9,[11][12][13][14][15][16][17][18][19][20][21][22]. GII.17 appeared as a dominant strain replacing the GII.4 strain in these regions during 2014-2015 [23].…”

“…In the winter of 2014-2015, a rare NoVs genotype, GII.17, emerged in most of the East Asian regions including China (Guangdong [9][10][11][12][13], Jiangsu [14], Zhejiang [15], Hebei [16], Hong Kong [17], Taiwan [18], Beijing [19], and Shanghai [20], Japan [21] and South Korea [22]). Soon after, the novel GII.17 strain became the most predominant NoV strain, replacing the pandemic strain GII.4 Sydney 2012, responsible for the majority of gastroenteritis outbreaks in this region [23].…”