Clinical relevance and genotypes of circulating noroviruses in northern Taiwan, 2006–2011

Abstract

The incidence of noroviral gastroenteritis has increased dramatically in recent years, and norovirus (NoV) genogroup II.4 (GII.4) is associated with outbreaks worldwide. The NoV genotypes and their clinical relevance in children hospitalized with acute gastroenteritis between 2006 and 2011 in northern Taiwan were evaluated in this study. NoV sequences were amplified from 47 clinical specimens and phylogenetic analysis was performed. Based on noroviral capsid protein (VP1) and RNA dependent RNA polymerase (RdRp) phylogeny, circulating NoV could be divided into GII.2, GII.3, GII.12, and GII.4 and GII.16, GII.12, GII.g, and GII.4; respectively. The GII.4 subtype was predominant and could be divided further into the 2004 (Hunter), 2006b, and 2010 (New Orleans) subtypes. Regarding clinical manifestations, convulsive disorder occurred only in cases caused by NoV GII.4 2006b. Patients affected by NoV GII.4 2006b presented with a higher frequency of diarrhea (P = 0.0204), longer duration of diarrhea (P = 0.0215), more frequent hypoglycemia (P = 0.038), and electrolyte imbalance (P = 0.0487) than acute gastroenteritis caused by NoV GII.4 2010. Structural analysis showed that the amino acid changes in viral VP1 between GII.4 2006b and 2010 subtype were located mainly in the protruding domain 2 (P2 domain). In conclusion, the NoV GII.4 variants 2006b and 2010 were the main causes of acute gastroenteritis in hospitalized children in northern Taiwan during 2006-2011. The clinical presentations and structural changes in VP1 of the two NoV GII.4 variants should be evaluated in the future.

High prevalence of GII norovirus in hospitalized children with acute diarrhea, in Beijing

“…Overall, the limitation is that number of cases in this study is small and there may be a bias, more investigation is needed in future. Almost all of the epidemiological studies show that GII.4 norovirus was the predominant genotype identified in presented genotyping data [33,34]. However, in this study, the total detection rate of GII.3 norovirus was reached 50%.…”

Intestinal microbiome in children with severe and complicated acute viral gastroenteritis

“…The genetic and environmental interactions of the intestinal microbiota are reportedly correlated with the progression of inflammatory bowel disease9. Acute viral gastroenteritis (AGE) can be associated with atypical manifestations, such as convulsions and intestinal hemorrhage101112. Recent studies found that the adaptive responses against commensals consist integral component of mucosal immunity in gastrointestinal infection, and following norovirus infection, patients who have a disrupted microbiota may be at elevated risk for long-term health complications1314.…”

Emergence of GII.Pg norovirus in gastroenteritis outbreaks in Victoria, Australia

“…In recent years, GII.Pg norovirus has been widely documented in individuals with gastroenteritis as well as in environmental samples. Reports of the detection of GII.Pg norovirus in humans include studies in Australia [Eden et al, 2010;Dunbar et al, 2014;Lodo et al, 2014], Belgium [Mathijs et al, 2011], China [Mei et al, 2011;Sang et al, 2014], France [Loury et al, 2015], Germany [Hoffmann et al, 2013], Italy [Medici et al, 2014], South Africa [Mans et al, 2014], Spain [Arana et al, 2014], Taiwan [Tsai et al, 2014], Tanzania [Moyo et al, 2014], and the United States [Takanashi et al, 2011]. GII.Pg norovirus has also been detected in sewage and surface waters in Argentina [Blanco Fernandez et al, 2011.…”

“…One genotype identified by ORF 1 nucleotide sequencing has been termed “GII.Pg.” It appears to be an obligatory recombinant, in that no unique GII.g ORF 2 sequence has been identified. So far, various studies have linked GII.Pg to two ORF 2 genotypes, GII.1 [Mathijs et al, ; Giammanco et al, ; Hoffmann et al, ; Lodo et al, ; Medici et al, ] and GII.12 [Mei et al, ; Takanashi et al, ; Arana et al, ; Medici et al, ; Sang et al, ; Tsai et al, ]. However, detailed studies on the emergence and molecular epidemiology of GII.Pg noroviruses are lacking and the precise relationship between the GII.Pg ORF 1 genotype and its ORF 2 recombinant forms has not been studied in detail.…”