Norovirus Activity and Genotypes in Sporadic Acute Diarrhea in Children in Shanghai During 2014–2018

Abstract

Background: Based on the impact public health of norovirus and the current progress in norovirus vaccine development, it is necessary to continuously monitor the epidemiology of norovirus infection, especially in children who are more susceptible to norovirus. Objectives: To monitor the activity and genotypes of norovirus infection in sporadic diarrhea in Shanghainese children during 2014–2018. Study design: Acute diarrheal cases were prospectively enrolled in the outpatient setting. Real-time reverse transcription-polymerase chain reaction was used for screening norovirus GI and GII genogroups. Dual norovirus genotypes were identified based on the partial capsid and polymerase gene sequences. Results: Of the 3422 children with diarrhea, 510 (14.9%) were positive for noroviruses with 13 (2.5%) strains being GI genogroup and 497 (97.5%) strains being GII genogroup. Five distinct capsid GII genotypes were identified, including GII.4-Sydney/2012 (71.8%), GII.3 (13.8%), GII.17 (7.8%), GII.2 (6.0%), GII.6 (0.3%) and GII.8 (0.3%). Seven polymerase GII genotypes were identified, including GII.Pe (77.0%), GII.P12 (11.0%), GII.P17 (9.0%), GII.P16 (2.1%), and GII.P7, GII.P8 and GII.P2 in each (0.3%). Eleven distinct polymerase/capsid genotypes were identified with GII.Pe/GII.4-Sydney/2012 (74.2%), GII.P12/GII.3 (11.7%) and GII.P17/GII.17 (7.7%) being common. GII.P17/GII.17 strains were detected since September 2014. Recombinant GII.P16/GII.2 strains were detected since December 2016. Conclusions: Norovirus is a major pathogen causing diarrhea in Shanghainese children. GII.Pe/GII.4-Sydney/2012 strains remained the predominant genotype. The emergence of GII.P17/GII.17 and GII.P16/GII.2 strains in sporadic diarrhea was consistent with norovirus-associated outbreaks attributable to these 2 novel variants in China. Continuous monitoring norovirus genotypes circulating in pediatric population is needed for current vaccine development.

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

“…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).…”

Recombinant GII.4[P31] Was Predominant Norovirus Circulating in Beijing Area, China, 2018–2020

“…In this study, the most prevalent norovirus was recombinant GII.4[P31] genotype in sporadic AGE children. It is similar to the study of sporadic cases in Shanghai from 2014 to 2018, in which the predominant genotype was GII.4 Sydney[P31] (Wang et al 2019). However, it is different with norovirus outbreaks studies in the past 5 years.…”

Prevalence of GII.4 Sydney Norovirus Strains and Associated Factors of Acute Gastroenteritis in Children: Winter 2019-2020 in Guangzhou

“…GII.4 norovirus can be further classi ed into seven strains (GII.4 US95/96 strain, GII.4 Farmington Hills, GII.4 Hunter, GII.4 Den Haag, GII.4 New Orleans, and GII.4 Sydney) due to its continuous variations. These novel GII.4 epidemic strains that are associated with AGE outbreaks usually mutate every 2-3 years [17,18]. This is because recombination frequently occurs between different strains and the breakpoints are usually at the junction of ORF1-2; hence, a dual typing based on both the RdRp of ORF1(P type) and the VP1 of ORF2 (genotype) of norovirus is widely used currently [8].…”