2012-2014年湖南省感染性腹泻哨点医院儿童诺如病毒感染及基因型别分析

目的 了解湖南省感染性腹泻哨点医院儿童诺如病毒的感染状况及基因型别。 方法 2012年1月-2014年12月采集湖南省哨点医院腹泻患儿的粪便标本,应用诺如病毒特异性引物进行扩增,选择扩增阳性产物进行基因测序和进化分析。 结果 936份粪便标本RT-PCR检测诺如病毒核酸,阳性100份,阳性率10.68%。对40份诺如病毒核酸阳性标本进行基因序列测定与分析,38份为GⅡ型,其中31份为GⅡ.4型。在31株GⅡ.4型中,Sydney 2012和GII.4 Den Haag 2006b各栓出14株。 结论 2012-2014年湖南省哨点医院儿童腹泻病例中诺如病毒的感染率较高,GⅡ.4是优势株,其中GⅡ.4 sydney 2012和Den Haag 2006b是主要型别。     

-起食源性诺如病毒GⅡ.4/Sydney_2012变异株感染暴发的调查

目的 调查广州市某高校急性胃肠炎病例的感染来源、传播途径和危险因素.方法 按照病例定义开展病例搜索,采用描述性流行病学和病例对照研究进行分析;样本采用RT-PCR检测诺如病毒核酸,阳性标本分析基因核苷酸序列并进行同源性分析.结果 2013年1月8-21日该校共发生诺如病毒感染性腹泻141例,罹患率为8.5‰(141/16 600);8-9日为发病高峰;病例无班级和宿舍聚集性;病例对照调查显示A餐厅为早期病例的感染场所(OR=3.46,95％CI:1.07～11.1 6),1月7日的午餐是可疑餐次(OR=4.34,95％CI:1.18～17.37),可疑食物是手撕鸡套餐(OR=17.82,95％CI:4.46～78.17);采集病例和厨工肛拭子、剩余食物及环境涂抹样等266份,诺如病毒RT-PCR检测阳性21份(17例),病例阳性率为42.8％(9/21),A餐厅厨工阳性率为29.6％ (8/27),经基因测序为GⅡ.4/Sydney_2012变异株,学生、教职工病例与厨工同源性为100％.结论 该次疫情为诺如病毒GⅡ.4/Sydney_2012变异株感染引起的急性胃肠炎暴发,其原因是携带病毒厨工污染食物所致,以食源性传播途径为主.     

荧光定量RT-PCR检测诺如病毒基因Ⅱ型方法的建立和评估

目的 建立灵敏、特异的诺如病毒基因Ⅱ型的荧光定量RT-PCR方法,用于临床腹泻粪便样本病毒的定量检测.方法 构建质粒DNA,并转录合成RNA作为标准品,建立和优化诺如病毒基因Ⅱ型荧光定量RT-PCR方法和反应体系,评价该方法的灵敏度、特异性、重复性,并进行临床粪便样本的检测.结果 此方法最低可以检出102拷贝数/μl,能特异地检出诺如病毒基因Ⅱ型,与诺如病毒基因Ⅰ型无交叉反应,与柯萨奇病毒B组、脊髓灰质炎病毒、肠道病毒、星状病毒、甲肝病毒、埃可病毒和轮状病毒无交叉反应.针对标准品,2次批内试验的荧光信号循阈值(Ct值)变异系数(CV)分别为1.60％、0.70％,2次批间试验的变异系数(CV)分别为0.40％、0.40％,均在5％以下.结论 本研究建立的实时定量RT-PCR检测诺如病毒基因Ⅱ型的方法,其灵敏度、特异性和重复性良好,可用于该病毒的快速检测.     

Using GI Syndrome Data as an Early Warning Tool for Norovirus Outbreak Activity

Objective

To assess the relationship between emergency department (ED) and urgent care center (UCC) chief complaint data for gastrointestinal (GI) illness and reported norovirus (NV) outbreaks to develop an early warning tool for NV outbreak activity. The tool will provide an indicator of increasing NV outbreak activity in the community allowing for earlier public health action to mitigate NV outbreaks.

Introduction

Norovirus infection results in considerable morbidity in the United States where an estimated 21 million illnesses, 70,000 hospitalizations, and 800 deaths are caused by NV annually (1). Additionally, NV is responsible for approximately 50% of foodborne outbreaks (1). Between January 2008 and June 2012, 875 NV outbreaks were reported to the Virginia Department of Health (VDH). To assist in detecting possible disease outbreaks such as NV, VDH utilizes the web-based Electronic Surveillance System for Early Notification of Community-based Epidemics (ESSENCE) to monitor and detect public health events across Virginia. ESSENCE performs automated parsing of chief complaint text into 10 syndrome categories, including a non-specific GI syndrome that serves as a proxy for GI illnesses like NV.

Methods

ED and UCC chief complaints parsed into the ESSENCE GI syndrome category were compared to confirmed and suspected NV outbreaks across four years. In this study, the analysis periods were defined as week 21 through week 20 of the subsequent year. GI syndrome visits as a proportion of all ED and UCC visits and NV outbreak counts were aggregated by week. Time-series, correlation, and logistic regression analyses were performed. Low NV outbreak activity weeks were defined as those with 4 or fewer outbreaks, and high NV outbreak activity weeks were those with 5 or more outbreaks. Based on low NV outbreak activity weeks, baseline and threshold values for the weekly percent of GI syndrome visits were calculated for each analysis period. Baseline calculation was the average weekly percent of GI syndrome visits from week 21 to week 31 and threshold value was baseline plus two standard deviations. Weekly percent of GI syndrome visits was compared to the threshold value to serve as an indicator of increasing NV outbreak activity.

Results

The study period was from May 18, 2008 to May 19, 2012 (Fig 1). A total of 1,425,728 GI syndrome visits and 804 confirmed and suspected NV outbreaks were analyzed. Weekly visits to ED and UCC facilities with GI syndrome were highly correlated with outbreaks of NV in the community (r =0.809, p <.0001). Median and mean number of NV outbreaks per week were 2 and 4, respectively (range 0–23). NV outbreaks were more prominent during the winter months with peaks occurring between weeks 3–9. Median and mean percent of GI syndrome visits per week were 10.2% and 10.5%, respectively (range 8.9%–12.8%). Weeks with high NV outbreak activity were more likely to occur when the weekly percent of GI syndrome visits had surpassed the threshold value (OR =110.7, 95% CI: 31.9–384.8). On average, weekly percent of GI syndrome visits surpassed the threshold value 1.25 weeks prior to the start of high NV outbreak activity weeks (range 0–3).

Conclusions

These results support the use of syndromic surveillance GI illness data as an early warning indicator of increasing NV outbreak activity in Virginia. This study identified that GI syndrome visits crossed a calculated threshold value on average 1.25 weeks before the initiation of high NV outbreak activity. Although NV outbreaks occur year round, this study attempted to identify an indicator to trigger meaningful risk communication to the community immediately prior to high NV outbreak activity with the goal of reducing the magnitude of NV outbreaks. This early warning tool for NV outbreak activity will be implemented in the following year to validate its effectiveness and timeliness in mitigating NV outbreaks in Virginia.Open in a separate windowPercent of Emergency Department and Urgent Care Center Visits with GI Syndrome and Reported Norovirus Outbreaks, Virginia, May 2008-May 2012.     

Novel intergenotype human norovirus recombinant GII.16/GII.3 in Bangladesh

Noroviruses (NoVs) are one of the major etiological agents of acute gastroenteritis in all age groups. In this study, we identified an intergenotype NoV recombinant strain in the fecal specimens of two male infants with acute diarrhea in Bangladesh. Phylogenetic analysis showed that the identified strains were recombinant NoV strains with a GII.3 capsid and a GII.16 polymerase gene. The recombination breakpoint was located in the ORF1/ORF2 overlap region. To the best of our knowledge this is the first report of a NoV recombinant GII.16/GII.3 strain worldwide.     

深圳地区婴幼儿诺如病毒感染的分子流行病学检测及分析

目的了解深圳地区婴幼儿属于人类杯状病毒（HuCV）的诺如病毒（NoV）的感染状况并对NoV阳性病毒株进行基因型分析。方法采集连续2个秋冬季腹泻流行期间在深圳市儿童医院就诊的临床检验已排除寄生虫、细菌性腹泻和轮状病毒检测结果为阴性的3岁以下腹泻患儿粪便标本226例，应用分型引物RT-PCR法进行检测NoVGⅠ和GⅡ群，扩增产物通过1．5％琼脂糖凝胶电泳鉴定；部分阳性标本测序，结合GenBank参考株相应核苷酸序列进行进化和型别流行特点分析。结果深圳地区婴幼儿NoV阳性率为10．62％（24／226），检测出NoV阳性株GⅡ／4群18株，GⅡ／3群5株；7至24月龄为NoV高发年龄段。结论NoV是深圳地区婴幼儿冬季腹泻的重要病原体之一，流行株为NoV-GⅡ／4。     

北京市2014－2018年诺如病毒急性胃肠炎暴发的影响因素分析

目的 分析2014－2018年北京市诺如病毒急性胃肠炎暴发的影响因素。方法 收集2014年4月至2018年3月北京市诺如病毒急性胃肠炎聚集性事件及暴发资料,应用非条件logistic回归模型分析诺如病毒急性胃肠炎暴发的影响因素。结果 北京市共报告由诺如病毒感染引起的急性胃肠炎事件765起,85.88%（657/765）为聚集性事件,14.12%（108/765）为暴发。在暴发中,70.37%（76/108）发生在2017年;84.26%（91/108）发生在冬、春季节;88.89%（96/108）发生在托幼机构及中小学;主要传播途径为人传人（81.48%,88/108）;93.52%（101/108）为GⅡ组诺如病毒感染引起。多因素logistic回归分析结果显示,在近郊区及远郊区发生的事件,出现暴发的风险分别是城区的1.84倍（95% CI：1.13～3.02）及3.78倍（95% CI：1.62～8.82）;在小学、中学及其他机构发生的事件,出现暴发的风险分别是幼儿园的6.26倍（95% CI：3.53～11.10）、14.98倍（95% CI：6.23～36.01）及8.71倍（95% CI：3.07～24.71）;就诊率低于全部事件就诊率中位数的,发生暴发的风险是就诊率高的2.29倍（95% CI：1.42～3.68）;传播途径为食源性的事件,发生暴发的风险为人传人传播的14.55倍（95% CI：3.15～67.07）。结论 加强郊区、中小学及其他机构诺如病毒暴发疫情的防控力度,急性胃肠炎患者积极就医,做好食源性疫情的防控及厨工的健康管理,有助于减少诺如病毒急性胃肠炎的暴发。     

广州市门诊5岁以下儿童诺如病毒感染基因型分析

目的了解2007-2008年广州市监测点医院门诊5岁以下儿童病毒性腹泻散发病例中诺如病毒感染状况及基因型别。方法收集广州市2007-2008年监测点医院门诊临床诊断为病毒性腹泻的患儿临床资料及粪便标本954份,采用ELISA方法检测诺如病毒、轮状病毒,将诺如病毒抗原阳性的标本用RT-PCR方法进行诺如病毒核酸扩增,将阳性产物回收、纯化并测序,结合GenBank中的相关序列进行型别流行特点分析。结果 954份标本中,ELISA方法检测各种病毒的抗原阳性率为诺如病毒18.8%(179/954),其中07年12.2%(32/262),08年21.2%(147/692),轮状病毒30.8%。诺如病毒腹泻病例发病高峰在8～11月份,2岁以下病例数占全部病例的91.6%,病例集中在6～23月龄。RT-PCR方法检测诺如病毒核酸阳性率为80.4%(144/179),144份诺如病毒核酸阳性标本经测序及与GenBank中的相关序列比对证实有1份是GⅡ2型,其余全部为GⅡ4型。结论诺如病毒是广州市门诊5岁以下儿童病毒性腹泻的常见病原之一,仅次于轮状病毒,常见于2岁以下婴幼儿,2007-2008年流行优势株基因型为GⅡ4型。     

昆明市幼儿病毒性腹泻病原学监测分析

目的 了解云南省昆明市病毒性腹泻的病原谱特征,探索其流行规律,以期为病毒性腹泻患儿临床治疗及制定有针对性的防控措施提供参考.方法 采集2018年1月至2019年12月因腹泻就诊的昆明市5岁以下患儿粪便标本,用实时荧光定量PCR方法进行核酸检测,检测轮状病毒、诺如病毒、腺病毒、星状病毒及札如病毒,并分析各种病毒的流行病学...