Acute gastroenteritis outbreaks caused by human astrovirus,1978-2021:A systematic review

Human astrovirus(HAstV)is one of the main pathogens that cause sporadic cases of acute gastroenteritis,sometimes leading to outbreaks.This study aimed to elucidate the epidemiological and etiological character-istics of HAstV outbreaks worldwide.Literature on HAstV outbreaks published before January 2022 was retrieved from the China National Knowledge Infrastructure,WanFang,WeiPu,PubMed,and Web of Science databases.Date,region,population,settings,transmission modes,clinical symptoms,and etiological characteristics of the outbreaks were collected and analyzed.Thirty-one articles on 32 HAstV outbreaks reported between November 1978 and October 2018 were included.The outbreaks mainly occurred in autumn(14/32,43.75%),and more of them were reported in 1996,2004,and 2017.Outbreaks were primarily dis-tributed in the Northern Hemisphere and mainly occurred in nursery centers and kindergartens(9/29,31.03%),hospitals(5/29,17.24%),and schools(4/29,13.79%).Viral genotypes were identified during 19 outbreaks,and HAstV-1 was predominant(8/19,42.10%).Eleven outbreaks were caused by mixed infection,and norovirus(9/11,81.82%)and rotavirus(5/11,45.45%)were the most common mixed pathogens.The transmission routes were reported in 9 outbreaks of mixed infection,and most(7/9)were related to water-borne and foodborne transmission.Although HAstV outbreaks are infrequently reported,it is necessary to con-sider HAstV in norovirus-negative gastroenteritis outbreaks.In addition,local Centers for Disease Control and Prevention should have the capacity to handle HAstV outbreaks and identify pathogens.

Changing predominance of norovirus strains in children with acute gastroenteritis in Shanghai,2018–2021

Norovirus(NoV)is a major pathogen that causes acute gastroenteritis(AGE)in people of all ages,especially in children.In this study,we investigated the molecular epidemiological characteristics of NoV in children with AGE in Shanghai from 2018 to 2021.The overall detection rate of NoV was 11.9%(181/1545),with annual detection rates of 9.4%(36/381),13.6%(29/213),5.8%(13/226)and 14.2%(103/725),respectively.Of note,the prevalence of NoV in 2020 was significantly lower than that in 2018-2019(10.9%,65/594)(P=0.023)and 2021(14.2%,103/725)(P=0.000).The 181 NoV strains identified in this study were classified into the GI group(1.1%,2/181),GII group(98.3%,178/181)and GIX group(0.6%,1/181)according to the VP1 gene.The most common NoV VP1 genotype was GII.4 Sydney_2012(63.5%,115/181),followed by GII.3(19.9%,36/181)and GII.2(9.4%,17/181).For P genotypes,174 strains were sequenced successfully according to the RdRp gene,and the predominant genotype was GII.P16(44.8%,78/174),followed by GII.P31(25.9%,45/174)and GII.P12(21.3%,37/174).Among the 174 cases,GII.4 Sydney_2012[P16](36.8%,64/174)was the dominant genotype,followed by GII.4 Sydney_2012[P31](25.3%,44/174),GII.3[P12](20.1%,35/174)and GII.2[P16](8.0%,14/174).In particular,the dominant genotypes in Shanghai changed from GII.4 Sydney_2012[P31]in 2018-2019 to GII.4 Sydney_2012[P16]in 2020-2021.This is the first report to describe the epidemiological changes in NoV infection before and during the COVID-19 pandemic in Shanghai.These data highlight the importance of continuous surveillance for NoV in children with AGE in Shanghai.

A large outbreak of acute gastroenteritis caused by the human norovirus GII.17 strain at a university in Henan Province,China

Background:Human noroviruses are a major cause of viral gastroenteritis and are the main etiological agents of acute gastroenteritis outbreaks.An increasing number of outbreaks and sporadic cases of norovirus have been reported in China in recent years.There was a large acute gastroenteritis outbreak at a university in Henan Province,China in the past five years.We want to identify the source,transmission routes of the outbreak by epidemiological investigation and laboratory testing in order to provide the effective control measures.Methods:The clinical cases were investigated,and analysed by descriptive epidemiological methods according to factors such as time,department,grade and so on.Samples were collected from clinical cases,healthy persons,the environment,water,and food at the university.These samples were tested for potential bacteria and viruses.The samples that tested positive for norovirus were selected for whole genome sequencing and the sequences were then analysed.Results:From 4 March to 3 April 2015,a total of 753 acute diarrhoea cases were reported at the university;the attack rate was 3.29%.The epidemic curve showed two peaks,with the main peak occurring between 10 and 20 March,accounting for 85.26%of reported cases.The rates of norovirus detection in samples from confirmed cases,people without symptoms,and environmental samples were 32.72%,17.39%,and 9.17%,respectively.The phylogenetic analysis showed that the norovirus belonged to the genotype GII.17.Conclusions:This is the largest and most severe outbreak caused by genotype GII.17 norovirus in recent years in China.The GII.17 viruses displayed high epidemic activity and have become a dominant strain in China since the winter of 2014,having replaced the previously dominant GII.4 Sydney 2012 strain.

Epidemiology of Norovirus among outpatients presenting with acute diarrhea in Dalian,China

The aim of this study was to perform an epidemiological analysis of the viral strains isolated from outpatients with acute gastroenteritis in Dalian,Liaoning province,China to determine the epidemiology of Norovirus(NoV).Fecal samples were collected from 789 outpatients with acute gastroenteritis in the Xigang district of Dalian,Liaoning province,China from July 2015 to December 2016.Norovirus was detected by real-time reverse transcriptase-polymerase chain reaction(RT-PCR).A selection of the positive samples identified was subsequently sequenced,and these data were analyzed by using the Norovirus Typing tool.Results showed that 38.02%(300/789)of the fecal samples were positive for NoV,of which 95.67%(287/300)were identified as genotype GII with 1.33%(4/300)identified as GI.A further 3.00%(9/300)were combined infections with both GI and GII Norovirus.When analyzing the age distribution,the infections primarily occurred in adults especially the elderly whose NoV positive rate was much higher than the average.Winter was the season whenmost cases were recorded during 2015 and 2016;however,another infection peak was observed in July 2016.Thirty Norovirus positive samples were successfully sequenced,and results showed that GII.4 was the most commonly identified genotype,along with GII.3 and GII.17.Norovirus is the most common pathogen for acute gastroenteritis in Dalian,Liaoning province of China.The current NoV genotype prevalence in Dalian was found to be similar to that in other regions of China.Genotype GII.4 was the most common genotype in our study,GII.3 and GII.17 were also identified.

Impact of rotavirus vaccine implementation on Israeli children:a comparison between pre-and post-vaccination era

Background Worldwide rotavirus vaccination has resulted in a substantial decrease in rotavirus-induced severe gastroenteritis and related hospitalizations among children.Still,the characterization of patients warranting hospitalization needs to be further elucidated.The purpose of the study is to compare the clinical and laboratory features of children hospitalized with acute rotavirus infection before and after the introduction of routine vaccination.Methods This is a retrospective observational study.Participants were pediatric patients who presented to the Bnai Zion Medical Center pediatric emergency department and were diagnosed with rotavirus acute gastroenteritis between 2017 and 2019.Results During the pre-vaccination period(2007–2009),114 infants and young children(median age:14 months,range:1–72 months;59 male,55 female)were hospitalized for rotavirus-induced acute gastroenteritis with a rate of 11.71 positive rotavirus tests per 1000 emergency room visits.In the post-vaccination period(2012–2019),168 infants and young children(median age:17 months,range:0–84 months;90 male,78 female)were hospitalized with a rate of 4.18 positive rotavirus tests per 1000 emergency room visits.There were no statistical differences between the two groups in gender,breast-feeding rates and sibling(s).The proportion of cases with moderate-to-severe dehydration was higher in the post-vaccination children than in the pre-vaccination children.Conclusions Rates of rotavirus-attributed acute gastroenteritis hospitalizations declined from the pre-to the post-vaccination period.Higher rates of dehydration were found in the post-vaccination children.Ongoing surveillance is warranted to better understand the implications of the vaccine.