河北省卢龙地区2008-2009年5岁以下腹泻住院儿童中诺如病毒的检测和分型

目的 了解河北省卢龙地区2008 -2009年5岁以下住院儿童中诺如病毒的分子流行病学特征.方法 收集2008年10月至2009年8月325例5岁以下腹泻住院患儿粪便标本和流行病学资料,采用酶联免疫吸附试验( ELISA)检测轮状病毒抗原,利用多重RT-PCR方法检测诺如病毒,并对部分诺如病毒阳性株进行序列测定和系统进化分析.结果 诺如病毒的检出率为11.3％ (37/325),仅次于轮状病毒的检出率(48.6％),高于腺病毒(6.5％)和星状病毒(4.3％),主要感染2岁以下儿童,季节高峰在11月,系统进化分析表明诺如病毒流行优势株为GⅡ-4/2006b变异株,并发现一株未见报道的新型GⅡ-4变异株.结论 诺如病毒是引起2008 -2009年卢龙地区的急性胃肠炎的重要病原之一,GⅡ-4/2006b变异株仍是流行优势株,要进一步监测新型GⅡ-4变异株的流行.     

长春地区2010年度婴幼儿腹泻的病原学研究及流行病学特点

目的了解长春地区四种主要腹泻病毒病原构成及流行病学特点。方法收集长春市儿童医院5岁以下住院患儿腹泻样本共460例,轮状病毒采用ELISA试剂盒检测,杯状病毒、星状病毒采用逆转录一聚合酶链反应（RT-PCR）法,腺病毒采用聚合酶链反应（PCR）法进行鉴定。结果460份标本中轮状病毒占35．22％（162／460）;杯状病毒占20．43％（94／460）,星状病毒占9．78％（45／460）,腺病毒占3．70％（17／460）,混合感染达7．17％（33／460）,发病患儿以2岁以下婴幼儿为主。对162份轮状病毒阳性标本进行G／P分型,结果示G1P[8]为主要流行株,杯状病毒以GII-4亚型为主要流行株,星状病毒为I型,腺病毒为Ad41。结论长春地区婴幼儿病毒性腹泻的病原中轮状病毒是最主要病原,其次为杯状病毒、星状病毒和腺病毒。     

2013年11月北京丰台区轮状病毒腹泻流行的实验室分析

目的 了解2013年11月北京市丰台区腹泻中轮状病毒和诺如病毒发病率升高的流行情况及其基因特征 方法 2013年11月在哨点医院门诊随机采集47份腹泻患者便标本、30份环境标本,使用real-time RT-PCR进行轮状病毒（rotavirus）和诺如病毒（norovirus）的筛查;并对轮状病毒阳性标本使用RT-PCR方法扩增VP4和VP7基因,扩增产物进行序列测定.使用Blast、BioEdit及Mega4.0等软件进行序列比对及基因进化分析.结果 47份粪便标本中,37份为轮状病毒检出率为78.7％（37/470,诺如病毒阳性率为14.9％（7/47）,轮状病毒和诺如病毒混合感染率为10.6％ （5/47）;30份环境标本中,轮状病毒检出率为23.3％ （7/30）,未检出诺如病毒.核酸序列比对及进化分析表明此次流行的轮状病毒为G9P[8]a型,与2010-2012年北京地区感染儿童的G9株高度同源.结论 2013年11月北京市丰台区其他感染性腹泻标本中以轮状病毒检出为主,其基因型别为G9P[8]a型,检出率远高于北京市往年水平,提示应加强对轮状病毒进行监测.     

长春地区婴幼儿腹泻人类杯状病毒感染的调查

目的了解长春地区婴幼儿腹泻人类杯状病毒(Human calicivirus,HuCV)感染的流行情况。方法用RT-PCR法检测腹泻患儿粪便标本中HuCV。结果长春地区婴幼儿腹泻HuCV检出率为18%。HuCV腹泻以2岁以下儿童为主(占96%)。流行高峰季节为11月至次年3月。选择19株HuCV进行分子鉴定,16株属GII-4群,2株属GII-3群,另一株属GI-2群,表明GII-4群为本地区优势株。5岁以下儿童中HuCV腹泻在年龄和季节分布上都与轮状病毒腹泻很相似。结论长春地区婴幼儿杯状病毒感染的流行病学调查为我国病毒感染性腹泻的预防和控制提供科学依据。     

2010—2011年兰州地区5岁以下腹泻患儿杯状病毒和腺病毒感染的流行特征

目的了解兰州地区腹泻患儿中杯状病毒和腺病毒感染的分子流行病学及临床特点。方法收集兰州大学第一医院2010年7月至2011年6月腹泻患儿粪便标本295份,采用RT-PCR或PCR的方法检测杯状病毒及腺病毒,腺病毒阳性标本利用多重PCR及巢式PCR的方法分型,并对序列进行分析。结果295份粪便标本中杯状病毒的检出率为13．2％（39／295）,腺病毒的检出率是5．1％（15／295）。分型结果显示：杯状病毒中69．2％为诺如病毒,其余是札如病毒,诺如病毒中以GII-3（13例）为主,其次为GII-4（12例）,GII-6（2例）;腺病毒主要以F组的41型（10／15）为主,同时还检测到1例A组的31型,2例B组的3型及C组的1例5型和1例6型,两种病毒均主要感染2岁以下儿童,无明显的季节高峰。结论杯状病毒和腺病毒是2010—2011年兰州地区病毒性腹泻患儿的重要病原,长期监测具有重要意义。     

2008-2014年GⅡ.4诺如病毒抗原表位进化研究

目的 了解新的GⅡ.4变异株相对于旧变异株在遗传和结构上的选择优势,研究近几年湖州市GⅡ.4型诺如病毒的进化替换规律.方法 收集从2008年到2014年湖州市GⅡ.4型诺如病毒13株,进行全长VP1区的序列测定,通过序列比对分析找到关键的变异位点.结果 湖州地区的GⅡ.4型诺如病毒在七年中经历了3次变异,2008年和2009年的诺如病毒与2006b variant聚成一个分支;2010和2011年检测到的病毒与2010 variant聚成一个分支;最近从2012年底一起暴发疫情中检测到的诺如病毒和2013年、2014年检测到的与国际上最新的2012 variant聚成一个分支.在氨基酸水平,我们找到77个信息位点（540个氨基酸中的14.3％）.其中39个位于P2区,N端4个,S区18个,P1区16个.结论 GⅡ.4型诺如病毒是全球范围内严重的病毒性肠胃炎首要原因.在过去的十几年时间里,诺如病毒GⅡ.4型已经引起了四次世界范围的急性胃肠炎流行暴发.新出现的变异株迅速并完全的替换已经正在流行的变异株.     

广州市5岁以下儿童病毒性腹泻流行特征

目的了解广州市5岁以下儿童4种主要腹泻病毒的流行病学特征。方法收集广州市2008年哨点医院门诊腹泻患儿粪便686份,采用ELISA法检测轮状病毒、腺病毒和星状病毒抗原,用RIDASCREEN ELISA试剂盒进行诺如病毒抗原检测,并对以上腹泻患儿的临床资料进行分析。结果686份标本中,4种病毒的阳性率：轮状病毒为34．0％、诺如病毒为20．7％、腺病毒为6．0％、星状病毒为1．2％,其中有混合感染的病例数占5．1％．以轮状病毒混合其他病毒感染为主,占85．7％。4种病毒阳性率男女差异无统计学意义,不同年龄组间阳性率差异有统计学意义（P〈0．05）,与年龄有关,均以2岁以下患儿为主,分别占阳性总数的93．1％、92．3％、87．8％和100％。轮状病毒有明显的季节特征,10～12月份为发病高峰,诺如病毒等常年均有发病,无特殊的时间分布。混合感染的患儿腹泻症状较重（P〈0．05）。结论4种病毒均有检出,以轮状病毒和诺如病毒为主,秋冬季为发病高峰,2岁以下为发病高危人群,同时混合感染现象值得关注。     

天津地区儿童轮状病毒腹泻的分子流行病学研究

目的了解天津地区婴幼儿轮状病毒感染腹泻情况及其型别特点。方法收集天津市儿童医院2008年8月到2009年7月腹泻患儿的粪便标本,先采用A组胶体金法快速检测RV抗原,将检测阳性的标本进行病毒RNA提取,RT—PCR扩增病毒VP7编码基因,并将部分PCR产物阳性标本进行测序,测序结果递交GentBand数据库进行BLAST搜索,及作同源性分析。结果1156份标本经胶体金法检测RV阳性305例,阳性率26．38％。阳性患儿中5岁以下占97％,5岁以上占3％;。轮状病毒有明显的季节特征,季节高峰从9月逐渐升高至次年2月为高发季节（18．4％～47．6％）,三月逐渐回落。其中1月份轮状病毒检出率最高,其次为10月、11月、2月。轮状病毒检出率最低的是6、7、8月。检测结果显示天津地区的优势株仍然是Gl型（72．7％）,其次是G3型（27．2％）。结论轮状病毒是天津地区婴幼儿腹泻的重要病原,5岁以下儿童为最主要的易感人群,流行基因型以G1为主。     

兰州地区5岁以下婴幼儿病毒性腹泻的分子流行病学研究

目的调查兰州地区5岁以下婴幼儿病毒性腹泻的流行情况,了解四种主要腹泻病毒在儿童中的分布情况。方法采集2009年7月至2010年6月兰州大学第一医院儿科5岁以下腹泻患儿粪便标本290份及儿童保健中心健康婴幼儿正常粪便标本114份,采用酶联免疫吸附试验（ELISA）检测轮状病毒抗原,采用巢式聚合酶链反应对轮状病毒阳性标本进行分型;采用反转录．聚合酶链反应（RT—PCR）检测杯状病毒和星状病毒,聚合酶链反应（PCR）检测腺病毒。结果290份腹泻标本中四种病毒的阳性率分别为：轮状病毒39．31％,杯状病毒11．38％,腺病毒10．69％,星状病毒4．83％;对114份轮状病毒阳性标本G、P分型,G3型及P[8]型为优势株;114份正常标本轮状病毒检出率为0,杯状病毒检出7例,星状病毒检出1例,腺病毒检出5例。结论病毒性病原在兰州地区婴幼儿腹泻中占有重要地位,长期系统的监测具有重要意义。     

2006-2015年成都地区5岁以下病毒性腹泻住院患儿病原学特征分析CSCD

目的 对成都地区5岁以下急性腹泻病患儿进行病毒学监测,了解引起腹泻常见病毒的流行特征,为指导病毒性腹泻的防控提供科学依据.方法 采集成都市妇女儿童中心医院儿童消化科2006年3月至2015年6月5岁以下腹泻住院患儿粪便标本,并送四川省疾病预防控制中心进行病毒RNA提取与检测,并记录患儿临床资料.采用ELISA、RT-PCR方法对轮状病毒抗原进行检测与分型;采用RT-PCR方法对杯状病毒、星状病毒、腺病毒进行检测与分型.结果 共收集1-59月龄腹泻住院患儿粪便标本份共2 331份（男1 446份,女885份）,阳性检出率58.0％,以7-12月龄为好发年龄.轮状病毒阳性检出率28.3％,11 -12月份为流行季节.杯状病毒阳性检出率23.3％,9月份为流行季节,诺如病毒GII为主要感染株,未发现暴发流行.星状病毒阳性检出率1.5％,主要于1-3月份检出.腺病毒阳性检出率5.1％,主要于5-8月份检出,2011年有过小流行.2007年以后,轮状病毒的检出率较前明显下降,而同时杯状病毒检出率逐年升高,2010-2015年杯状病毒成为引起5岁以下患儿腹泻的主要病毒之一.绝大多数病毒性腹泻患儿为急性病程（91.2％）,以轻度脱水为主,其次为中度脱水,无重度脱水.可伴消化道外表现,轮状病毒的消化道外表现较杯状病毒多见,但在随访中均恢复正常.结论 病毒性腹泻是5岁以下儿童急性腹泻病常见原因,成都地区以轮状病毒、杯状病毒为主要病原体.     

Molecular epidemiology of norovirus infection among children with acute gastroenteritis in Shanghai,China, 2001–2005

Norovirus is one of the major causes of outbreaks and sporadic cases of acute gastroenteritis in young children worldwide. Obtaining local baseline information regarding this virus is important for developing and evaluating prevention strategies of norovirus transmission in children. The age, seasonal distribution and circulating genotypes of norovirus in Shanghai, China, between 2001 and 2005 were determined. Of 5411 stool specimens collected from children under 5 years of age who were hospitalized with acute gastroenteritis 3,975 were rotavirus‐negative, indicating the presence of another causative agent. From these specimens, 484 were selected at random for genotyping, and 45 were norovirus‐positive. Norovirus infection was detected in all age groups, but infants less than 6 months old showed the lowest prevalence (5.4%). Norovirus infections peaked from August to November. Among the 37 identified norovirus strains, 2 were GII‐3, 2 were GII‐7, and 33 were GII‐4 genotypes. This study demonstrated the impact of norovirus infection causing acute gastroenteritis in hospitalized children and the importance of vaccination against norovirus diarrhea in Shanghai, China. J. Med. Virol. 81:1826–1830, 2009. © 2009 Wiley‐Liss, Inc.     

Molecular epidemiology of norovirus gastroenteritis outbreaks in New Zealand from 2002-2009

Noroviruses are the most common cause of acute non-bacterial gastroenteritis outbreaks worldwide, including New Zealand. New Zealand has a population of 4.4 million, which allows for centralized outbreak surveillance and a Norovirus Reference Laboratory, which facilitates efficient diagnosis, surveillance, and tracking of norovirus outbreaks. Norovirus outbreak strains are identified, sequenced, and compared with international reference strains. Between January 2002 and December 2009, 1,206 laboratory-confirmed norovirus outbreaks were recorded. The predominant outbreak settings were healthcare institutions for the elderly and acute care patients. Other outbreak settings included catering establishments, cruise ships, homes, community events, school camps, child-related settings, and consumption of contaminated shellfish. Of the 1,206 outbreaks, 105 (8.7%) were caused by norovirus genogroup I (GI) strains, 1,085 (89.9%) were caused by genogroup II (GII) strains, and both GI and GII strains were detected in 9 (0.8%) outbreaks. The genogroup was not identified in 7 (0.6%) outbreaks. A range of norovirus genotypes, including GI genotypes 1-6, GII genotypes 2-8, and GII.12, were associated with these outbreaks. The predominant genotype was GII.4, which was identified in 825 (68.4%) outbreaks. Norovirus GII.4 variant strains, including 2002 (Farmington Hills), 2004 (Hunter), 2006a (Laurens, Yerseke), 2006b (Minerva), and 2010 (New Orleans) implicated in overseas outbreaks also occurred in New Zealand, providing evidence of global spread.     

深圳市儿童秋冬季腹泻诺如病毒检测及基因型分析

目的 了解深圳市儿童秋冬季腹泻中诺如病毒（Nov）的感染状况,并对阳性株进行基因型分析.方法 收集深圳地区多家医院2009年9月至2010年1月腹泻患儿粪便标本307份,通过逆转录-聚合酶链反应（RT-PCR）方法进行诺如病毒核酸扩增,部分阳性标本的PCR产物经纯化、测序,结合GenBank参考株相应核酸序列构建系统进化树并进行基因型分析,采用SimPlot3.5.1对重组株进行分析和鉴定.结果 307份粪便标本中诺如病毒核酸阳性38例,阳性率为12.4％,以6～24个月龄婴幼儿感染为主,占全部病例数的81.6％（31 /38）,感染的发病高峰为10、11月份,占全部病例数的73.7％ （28/38）;26份测序标本中25株属于GⅡ.4型2006b变异体,1株为GⅡ.12/GⅡ.3型重组株.结论 诺如病毒是深圳市儿童秋冬季腹泻的重要病原体,优势流行株为GⅡ.4型2006b变异体,深圳首次检出的诺如病毒重组株为GⅡ.12/GⅡ.3型.     

Changing distribution of norovirus genotypes and genetic analysis of recombinant GIIb among infants and children with diarrhea in Japan

A total of 402 fecal specimens collected during July 2003-June 2004 from infants and children with acute gastroenteritis, encompassing five localities (Maizuru, Tokyo, Sapporo, Saga, and Osaka) of Japan, were tested for the presence of norovirus by RT-PCR. It was found that 58 (14.4%) fecal specimens were positive for norovirus. Norovirus infection was detected throughout the year with the highest prevalence in December. Norovirus GII was the most predominant genogroup (98.3%; 57 of 58). The genotypes detected in this study were GI/4, GII/2, GII/3, GII/4, and GII/6. Of these, NoV GII/3 (known as the Arg320 virus cluster) was the most predominant genotype (43.9%), followed by NoV GII/4 (the Lordsdale virus cluster; 35.1%) and others. Two norovirus strains clustered with a "new variant designated GIIb" and a "new variant of GII/4" were found circulating in Japan for the first time. It was interesting to note that NoV GIIb and NoV GII/3 appeared to be the recombinant strains and the recombination site was demonstrated at the overlap of ORF1 and ORF2. The majority (96%) of the dominant norovirus strains were identified as the recombination of GII/3 capsid and GII/12 polymerase. The recombination in the NoV GIIb capsid gene at the breakpoint located at P1 domain was also identified. Obviously, NoV GIIb isolate in Japan had double recombination. This is the first report demonstrating the existence of different "new variants" co-circulating in Japanese infants and children with acute gastroenteritis.     

Molecular epidemiology of human calicivirus infections in children with acute diarrhea in Shanghai: a retrospective comparison between inpatients and outpatients treated between 2006 and 2011

Human caliciviruses (HuCVs), especially noroviruses, are currently the second leading cause of acute diarrhea in children; however, data are limited in Shanghai and other regions of the world regarding the epidemic difference of HuCV infections between inpatients and outpatients. Fecal samples (n = 1110) were collected from children up to age 5 years with acute diarrhea treated as inpatients or outpatients at Children’s Hospital of Fudan University in Shanghai, between 2006 and 2011. Human calicivirus was detected and genotyped using an RT-PCR assay for the RdRp gene. Among inpatients, 206 HuCV-positive samples (30.6 %) were detected as positive for norovirus. The predominant norovirus genotype was GII.4 (75.5 %), followed by GII.12 (22.3 %), GII.7 (1.0 %), and GII.b (1.0 %). Among outpatients, 128 samples (29.4 %) were positive for HuCV. Of these, 126 were positive for norovirus and two were positive for sapovirus. The predominant norovirus genotypes causing infections in outpatients were GII.4 (71.8 %) and GII.b (15.6 %), followed by GII.12 (9.5 %), GII.7 (0.8 %), and GII.2 (0.8 %). The GII.4-2006b variant was the predominant subtype both in inpatients and outpatients. Characteristics of the HuCV epidemic differ between inpatients and outpatients. Continued surveillance is vital to determine the molecular prevalence of HuCV and to develop effective vaccines.     

Detection of GII‐4/2006b variant and recombinant noroviruses in children with acute gastroenteritis,South Korea

Norovirus (NoV), a single‐stranded, positive RNA virus, is an important etiologic agent of acute gastroenteritis in children worldwide. In this study, a total of 434 fecal samples collected from 434 children with acute gastroenteritis in Seoul, between September 2007 and July 2008 were tested to determine the molecular epidemiology of NoVs and characterize recombinant strains by using RT‐PCR followed by sequencing. Of the 434 specimens, NoV, rotavirus, and adenovirus were detected in 155 (35.8%), 72 (16.6%), and 19 specimens (4.3%), respectively. NoV GI was detected in 7 specimens (1.6%) and GII in 148 (34.1%) specimens. Phylogenetic analysis of capsid sequences in the GII‐positive specimens revealed the presence of the following strains: GII‐4, 111 (75.0%); GII‐3, 35 cases (23.6%); GII‐6b, 1 case; and GII‐16, 1 case. Most of the GII‐4 strains were grouped with the GII‐4/2006b variant with 98–100% nucleotide identity. Eleven strains were identified as recombinant (GII‐4/GII‐3 in 10 cases and GII‐b polymerase/GII‐16 capsid in 1 case) by sequencing based on the RdRP and capsid genes. The putative recombination point in the recombinant strains was the ORF‐1/ORF2 overlap, located at nucleotide 5,046 with reference to Lordsdale. In conclusion, GII‐4/2006b variants were detected predominantly and a new recombinant strain (GII‐4/GII‐3) was found in the Korean children with gastroenteritis. Continuous monitoring of the genetic diversity of NoVs is important to determine the trend of the predominant genotype and new recombinant strain. J. Med. Virol. 82:146–152, 2010. © 2009 Wiley‐Liss, Inc.     

Molecular epidemiology of norovirus variants detected in children under five years of age in Hyderabad,India

PurposeNoroviruses are common viral agents in acute diarrhea in all age groups worldwide. Norovirus has been classified into 10 genogroups, GI to GX with over 48 genotypes among them the GII.4 genotype has evolved over time with a clear pattern of periodic variant replacement. Immunity is strain or genotype specific with little or no protection conferred across genogroups. The present study was aimed to determine the epidemiology, prevalent genotypes of norovirus in children below five years of age in the Hyderabad region, India.MethodsThe stool samples and clinical data were collected from 458 children below 5 years of age comprising of cases with acute gastroenteritis (n ?= ?366) and a control group (n ?= ?92) admitted to the pediatric ward. All the samples were tested for Norovirus by ELISA and RT-PCR. Sequencing was done for predominant strains.Results10.3% (n ?= ?38) of cases and 3.2% (n ?= ?3) of the control group were found to be Norovirus positive. Predominant genotypes were GII-82.5% followed by GI-12.5%.ConclusionSequencing and Phylogenetic analyses of 20 GII.4 strains was done. All of the isolates are clustered away from published the GII.4 variants thus suggesting the appearance of a new variant.     

Molecular epidemiology of noroviruses in children under 5 years of age with acute gastroenteritis in Yaoundé, Cameroon

Norovirus is a common cause of acute gastroenteritis (AGE) among children in developing countries. Limited data on the prevalence and genetic variability of norovirus are available in Cameroon, where early childhood mortality due to AGE is common. We tested 902 fecal specimens from children younger than 5 years of age hospitalized with AGE between January 2010 and December 2013. Overall, 76 (8.4%) samples tested positive for norovirus, of which 83% (63/76) were among children below 12 months old. Most of the noroviruses detected were in children infected between July and December of each year. All norovirus-positive specimens were genotyped, with 80% (61/76) being GII.4 (three variants detected). Genotypes GI.2, GI.6, GII.1, GII.2, GII.3, GII.6, GII.16, GII.17, and GII.21 were also detected. Interestingly, GII.4 Sydney and GII.17 Kawasaki viruses were found as early as 2010, years before their emergence globally. This study suggests norovirus is a significant cause of moderate to severe gastroenteritis among young children in Cameroon. The results are important to highlight appropriate prevention and control strategies for reducing the burden of norovirus disease.     

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

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.