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

Abstract

Background Noroviruses (NoVs) are considered an important cause of acute gastroenteritis (AGE) across all age groups, especially in children under 5 years of age. We investigated the epidemiology of noroviruses in outpatient children from the Children’s Hospital of Fudan University in Shanghai, China. Methods Stool specimens were collected between January 2012 and December 2017 from 1433 children under 5 years of age with acute gastroenteritis. All samples were analysed by conventional reverse transcription-polymerase chain reaction (RT-PCR) for genogroup II NoVs amplifying both the RNA-dependent RNA polymerase (RdRp) and partial capsid genes. The Norovirus Genotyping Tool v.2.0 ( https://www.rivm.nl/mpf/typingtool/norovirus/ ) was used for genotyping the strains, and phylogenetic analyses were conducted by MEGA 6.0. Results From 2012 to 2017, GII NoVs were detected in 15.4% (220/1433) of the samples, with the highest detection rate in children aged 7–12 months (19.2%, 143/746). The seasons with the highest prevalence of GII NoVs infection were autumn and winter. Based on genetic analysis of RdRp, GII.Pe (74.5%%, 137/184) was the most predominant RdRp genotype from 2013 to 2017, while GII.P4 played a dominant role in 2012 (55.6%, 21/36). Among the capsid genotypes, the most prevalent NoV genotype from 2012 to 2017 was GII.4 (74.1%, 163/220). On the basis of genetic analysis of RdRp and capsid sequences, the strains were clustered into − 19 RdRp/capsid genotypes, and 12 of them were discordant, such as GII.Pe/GII.4-Sydney_2012, GII.P12/GII.3, GII.P7/GII.6, GII.Pe/GII.3, and GII.P16/GII.2. Starting with 2013, GII.Pe/GII.4-Sydney_2012 had completely replaced the pandemic GII.P4-2006b/GII.4-2006b subtype and was detected in children across all age groups. Conclusions The present study shows high detection rates and the genetic diversity of circulating NoV GII genotypes in paediatric AGE samples from Shanghai. The findings emphasize the importance of continuous molecular surveillance of emerging NoV strains.

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).…”

“…The low prevalence of norovirus infection among older children could be due to acquired immunity through previous exposures (Gupta et al, 2018). Norovirus GII infections were predominant, representing 97.5% of the total norovirus infections, which is consistent with studies from other parts of Indonesia and other countries (Athiyyah et al, 2019;Lu et al, 2019;Mathew et al, 2019;Nirwati et al, 2019;Wang et al, 2019). GII noroviruses are more closely related to diseases that require medical treatment, whereas GI noroviruses result in mild symptoms and do not require hospitalization (Siafakas et al, 2018).…”

Evolution of the GII.3[P12] Norovirus from 2010 to 2019 in Jiangsu, China

“…Up to now, noroviruses are phylogenetically classified into 10 genogroups (GI-GX) and, among them, at least five genogroups (GI, GII, GIV, GVIII and GIX) could infect humans [ 5 ]. GII.3 is a common cause for sporadic infection in infants and children as the second major genotype after GII.4 in China [ 6 , 7 ]. To date, more reports focus on norovirus genotypes, such as GII.2[P16], GII.4, and GII.17[P17], that cause outbreaks.…”

Sequencing of Norovirus in Southern, Nigeria: Prevalent Genotypes and Putative GII.4 Novel Recombinants among Children

“…ORF 3 encodes a minor structural protein [9]. In spite of the large genetic diversity of norovirus, it is noteworthy that norovirus of the genotype GII.4 are responsible for a majority of infections [10,11].…”