Molecular epidemiology of noroviruses in children in South Greece, 2013‐2015

Abstract

Noroviruses constitute the leading cause of acute, nonbacterial gastroenteritis that affects both children and adults in healthcare and community settings. The current study attempted to provide insight on the molecular epidemiology of noroviruses in children in South Greece. Genotypic characterization of 69 norovirus strains detected in stool samples from children with gastroenteritis during a period of 30 months (January 2013 to June 2015) was performed on the basis of ORF2 (VP1 capsid) gene sequences. The results revealed the circulation of a diverse variety of norovirus genotypes. GII.4 was the predominant genotype (74%), followed by GII.2 (8.7%), GII.3 (5.8%), GII.6 (2.9%), GI.2 (2.9%), and four strains identified as GII.1, GII.7, GII.8, and GII.13, respectively. Phylogenetic analysis showed that most of the strains were closely associated with norovirus strains that circulated globally either in outbreaks and sporadic cases of gastroenteritis or in the environment during the last 4 years. Οf the GII.4 strains, 80.4% were detected between January 2013 and February 2014, indicating a possible ongoing epidemic. The incidence of other genotypes remained constant throughout the study period. Genotypic and phylogenetic analysis showed the predominance of the "Sydney 2012" variant among the GII.4 strains, whereas one GII.4 strain was identified as a "New Orleans 2009" variant. Five GII.4 strains showed significant nucleotide and amino acid sequence divergence from either the "Sydney 2012" or the "New Orleans 2009" variant, and these divergent strains might represent an emerging GII.4 variant.

Molecular epidemiology and genetic diversity of norovirus infection in children hospitalized with acute gastroenteritis in East Java, Indonesia in 2015–2019

“…We also observed that norovirus infection was found extensively in children <2 years old, with a significantly higher prevalence compared to that among children ≥2 years old (P = 0.01). Although norovirus infection occurred in all age groups, the children <2 years old appeared to be more vulnerable, which is consistent with other reports (Wu et al, 2020;Louya et al, 2019;Lu et al, 2019;Siafakas et al, 2018). The low prevalence of norovirus infection among older children could be due to acquired immunity through previous exposures (Gupta et al, 2018).…”

Genetic diversity and epidemiology of Genogroup II noroviruses in children with acute sporadic gastroenteritis in Shanghai, China, 2012–2017

“…In accordance with previous studies that concluded that noroviruses mainly peaked in cold seasons [20, 22, 26–28], our study demonstrated that most NoV infections were detected in autumn and winter. However, in some other areas, NoV-associated diarrhoea had a summer peak or no apparent seasonal peak, which may be connected with an increase in contaminated water and food or other unknown reasons [21, 29].…”

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

“…In accordance with previous studies that concluded that noroviruses mainly peaked in cold seasons [20,22,[26][27][28], our study demonstrated that most NoV infections were detected in autumn and winter. However, in some other areas, NoVassociated diarrhoea had a summer peak or no apparent seasonal peak, which may be connected with an increase in contaminated water and food or other unknown reasons [21,29].…”