攀枝花地区0～5岁儿童轮状病毒腹泻的分子流行病学研究

目的探讨攀枝花地区2009年10～12月婴幼儿轮状病毒腹泻的分子流行病学特征及临床特点。方法采用胶体金免疫层析法、逆转录-聚合酶链法(RT-PCR)对收集的婴幼儿腹泻标本270份进行轮状病毒检测及A组轮状病毒常见的G、P基因分型研究。结果 270份腹泻标本轮状病毒阳性率为38.6%;6月～2岁年龄组的阳性率为45.4%(89/196),2～5岁年龄组的阳性率为20.3%(15/74),两组对比差异有统计学意义(P﹤0.005);104例被检测的A组轮状病毒腹泻粪便标本中G分型以G2为主,P分型以P4为主。结论轮状病毒是攀枝花地区婴幼儿腹泻的主要病原,G2型和P4型为2009年的优势毒株。该病毒引起的小儿腹泻主要发生在秋冬季,6月～2岁婴幼儿是轮状病毒的易感人群。     

2009-2020年我国轮状病毒腹泻流行特征和基因型变化趋势

目的 了解2009-2020年我国全人群腹泻患者中轮状病毒感染者的流行特征和基因型变化趋势,为进一步开展腹泻监测和防控提供科学依据。方法 资料来源于国家科技重大专项传染病监测技术平台信息管理系统的我国28个省份252家哨点医院腹泻症候群监测数据,采用描述性流行病学方法分析2009-2020年轮状病毒腹泻病例在不同气候带地区、人群以及时间的分布特点及A组轮状病毒腹泻病例的基因分型特征和变化趋势。结果 2009-2020年共对114 606例腹泻病例进行轮状病毒检测,轮状病毒阳性率为19.1%（21 872/114 606）,阳性病例以A组轮状病毒为主（98.2%,21 471/21 872）。轮状病毒阳性率较高的年份分别为2009年（36.9%,2 436/6 604）和2010年（30.6%,5 130/16 790）,2011-2017年在14.0%~18.0%之间变化,2018年小幅上升（20.3%,2 211/10 900）,之后两年连续下降（15.5%,2 262/14 611和9.5%,470/4 963）。男性（20.2%,13 660/67 471）的轮状病毒阳性率明显高于女性（17.4%,8 212/47 135）;＜5岁婴幼儿的轮状病毒阳性率最高（28.4%,18 261/64 300）,是成年人的4倍以上。中温带、暖温带及亚热带地区的轮状病毒阳性率于12月至次年2月达高峰,而高原寒带存在2个高峰,分别出现在11月至次年1月及5-6月。2009-2020年A组轮状病毒优势基因型由G3P［8］、G1P［8］逐步发展为G9P［8］。结论 2009-2020年我国轮状病毒感染总体呈现下降趋势,呈明显的季节性流行,各年龄组人群阳性率差异较大,儿童腹泻仍是重点关注的问题,需进一步加强轮状病毒疫苗的接种,持续开展流行特征和基因型变化的监测。     

Molecular characterization of genotype G6 human rotavirus strains detected in Italy from 1986 to 2009

Group A human rotavirus (HRV) strains with a bovine-like (G6) major outer capsid protein VP7 were first detected in Palermo, Italy, in the late 1980s, and subsequently worldwide. During a 25-year rotavirus surveillance period, additional HRV G6 strains, associated with either a P[9] or P[14] VP4 genotype, have been detected sporadically, but repeatedly, in Palermo. Whether these G6 HRVs were transmitted to humans directly from an animal reservoir or could have circulated at low prevalence in susceptible individuals is uncertain. Upon sequence analyses of the VP7, VP4, VP6, NSP4 and NSP5 gene segments, all the Italian HRV strains displayed a conserved genotype constellation, G6-P[9]/[14]-I2-E2-H3. Intra-genotypic lineages and/or sub-lineages were observed among the various HRV strains, with some lineage/sublineage combinations being retained over time. Interestingly, two epidemiologically unrelated G6P[9] viruses, collected in the same rotavirus season, were found to have a clonal origin. In conclusion, our results indicate not only diverse origin of animal derived G6 HRVs in Palermo but also suggest human-to-human transmission of certain strains.     

Molecular epidemiology of human rabies viruses in Sri Lanka

Rabies is a lethal zoonotic disease caused by the rabies virus, which is transmitted by rabid animals to humans. Rabies is prevalent in all continents, with over 60% of human deaths occurring in Asia. Sri Lanka is a rabies-endemic country. This study shows that rabies afflicted more older individuals than children in Sri Lanka between 2008 and 2010. This novel finding indicates that older people in Sri Lanka should be more aware of the risk of rabies. Phylogenetic analyses of the rabies N and G genes showed that the Sri Lankan rabies viruses are distinct and probably originated from a single clone. The G–L noncoding region is highly diverse, and is suitable for the analysis of virus evolution within a country. A phylogenetic analysis of this region showed high diversity in the currently circulating Sri Lankan rabies viruses, which can be divided into seven clades. Some clades are unique to a specific geographic region, whereas others occur at multiple locations. This indicates that the movement of dogs, the main rabies-transmitting animal in Sri Lanka, is restricted in some areas but less limited in others. These data may help to formulate a more efficient rabies control program in Sri Lanka.     

杭州地区2014-2015年急性胃肠炎患者感染诺如病毒的流行病学特征分析

目的 了解2014-2015年杭州地区急性胃肠炎患者中诺如病毒的流行病学特征。方法 收集1 109份急性胃肠炎患者的临床流行病学资料和粪便样本,采用一步法双重荧光RT-PCR对样本中诺如病毒(GⅠ、GⅡ型)进行初筛,然后随机选择诺如病毒阳性的样本核酸进行多重RT-PCR扩增,对产物进行测序分析。结果 1 109份的粪便样本中,诺如病毒检出率为26.87%(298/1 109),以GⅡ亚型为主,占25.52%(283/1 109),GⅠ亚型占1.35%(15/1 109);不同性别人群诺如病毒检出率差异无统计学意义(P>0.05);不同年龄组人群中诺如病毒检出率分别为16.94%(<5岁)、19.45%(5~18岁)和32.26%(≥18岁);全年均可检出诺如病毒感染,高发季节为12月至次年3月,阳性率为29.67%~37.08%。序列分析显示,GⅡ基因亚型中以GⅡ-4/Sydney株为主(46.43%,13/28),其次为GⅡ-4/2006b株;GⅠ基因亚型中以GⅠ-1亚型为主(55.56%,5/9)。结论 诺如病毒是导致2014-2015年杭州地区急性胃肠炎的主要病原之一,GⅡ基因亚型特别是GⅡ-4/Sydney变异株和GⅡ-4/2006b变异株是该地区流行的优势毒株。     

中国部分地区大肠埃希菌O157的分子分型及变异研究

目的了解出血性大肠埃希菌（EHEC）O157的分子流行特征和遗传变异关系并完善EHECO157：H7感染性腹泻监测制度。方法采用聚合酶链反应分析毒力基因的分布情况；用脉冲场凝胶电泳技术对1988-2005年部分地区分离到的249株EHECO157：H7（其中产志贺毒素的245株，不产志贺毒素的4株）和51株O157非H7进行分子流行病学分析。结果stx2基因在我国的EHECO157：H7菌株中有着很高的分布率，部分菌株携带stx2基因变种。300株O157共分为161种带型，其中51株O157非H7菌株共有42种带型，4株O157：H7非产毒株分别为4种带型，245株EHECO157：H7共有115种带型。结论EHECO157间的基因变异较大；产stx2原毒素的菌株和5衄2毒素发生变异的菌株带型相差较大。部分菌株之间存在着一定的交叉，说明虽然这两大类菌株有其特有的流行克隆系，但是它们的克隆系之间亲缘关系较近。     

The antigenic diversity of rotaviruses: Significance to epidemiology and vaccine strategies

Rotaviruses are the major cause of infantile gastroenteritis world-wide. Much antigenic diversity exists amongst them. This has important implications to diagnosis, epidemiology and vaccination strategies. The nature of this diversity is now well understood. This review outlines and discussed our current knowledge of the subject from a historical perspective.     

山东省1990 ～ 1998 年肾综合征出血热流行特征及其变化趋势

山东省是我国肾综合征出血热 (ＨＦＲＳ)流行最严重的疫区 ,其发病人数占全国发病总数的 1/3左右[1] 。笔者分析了山东省ＨＦＲＳ流行特征及其变化 ,旨对ＨＦＲＳ综合防制工作有一定的指导作用1 .流行概况 :在 1995～ 1998年ＨＦＲＳ发病率为 19.19/10万 ,病死率为 0 .42 % ,分别比 1990～ 1994年发病率 10 .15 /10万和病死率 0 .90 %上升和下降 (χ2 =12 784.47,Ｐ <0 .0 0 0 1;χ2 =10 5 .12 ,Ｐ <0 .0 0 0 1)。ＨＦＲＳ发病高峰在 1995年 ,发病率为 2 6 .0 8/10万 ,病死率为 0 .48%。山东省共有141个县 (区 ) ,1990～ 1998年ＨＦＲＳ发病…     

重庆地区婴幼儿轮状病毒腹泻VP7型别分析

目的：研究重庆地区1998－2000年度秋冬季婴幼儿轮状病毒腹泻分子流行病学,方法：采用逆转录－聚合酶链反应（RT－PCR）扩增婴幼儿腹泻便样中的编码轮状病毒VP7蛋白的全基因片段（1062bp),再用巢式－聚合酶链反应（net-PCR)对扩增得到的VP7基因进行分型,同时利用核苷酸序列分析方法进行分型。结果：在1998－1999年度130例婴幼儿腹泻便样中VP7基因阳性者50例（38．46％）,其中G1型占88％（44／50）,G3型占8％（4／50）,混合型占4％（2／50）,均为G1＋G3型,而1999－2000年度轮状病毒流行季节采集的112 标本中VP7基因扩增阳性者38例（33．93％）,其中G3型占78．95％（30／38）,G1型占13．16％（5／38）,混合型占7．89％（3／38）,均为G1＋G3型,苷酸序列分型结果与PCR分型结果一致。结论：重庆地区 1998－1999年度轮状病毒流行季节中流行的轮状病毒以G1型为主,而1999－2000年度轮状病毒流行季节中G3型为主,在连续两年的监测中出现轮状病毒血清型的转变。     

Changing molecular epidemiology of rotavirus infection after introduction of monovalent rotavirus vaccination in Scotland

BackgroundRotaviruses (RV) are the leading cause of gastroenteritis in children less than five years of age worldwide. Rotarix®, a live attenuated monovalent vaccine containing a RV strain of G1P[8] specificity has been included in the childhood immunisation schedule from June 2013 in Scotland. This study aimed to characterise the prevalent RV strains in Scotland before and after the introduction of the RV vaccine.MethodsRV positive faecal samples from Scottish virology laboratories covering the years 2012–2015 were genotyped. Viral RNA was extracted from faecal suspensions. VP7 and VP4 gene specific primers were used for multiplex hemi-nested PCRs and sequencing. Mann-Whitney U test and Chi-square test were used for statistical comparison.ResultsThere was a decrease in RV positive samples from the Scottish virology laboratories from 7409 samples in the pre-vaccination years (2009–2013) to 760 in 2014–2015, with an annual reduction of RV infections by 74.4% (RR-3.95; 95%-CI, 3.53–4.42, p < 0.001). 362 samples from the pre-vaccination period and 278 samples from the post-vaccination were genotyped. There was a drop in prevalence of G1P[8] strains (72.1%, 95%-CI, 67.42–76.33 to 15%, 95%-CI, 11.38–19.79) after introduction of the vaccine. In the post-vaccination period G2P[4] was the dominant strain in Scotland (21.9%, 95%-CI, 17.48–27.17) with increase in G9P[8] (12.9%, 95%-CI, 9.50–7.41), G12P[8] (12.2%, 95%-CI, 8.89–16.60) and G3P[8] (11.9%, 95%-CI, 8.58–16.20) infections. Phylogenetic analysis of the VP7 and VP4 genes showed no major differences between the pre and post-vaccination G1P[8] strains.ConclusionThis laboratory based surveillance study shows significant reduction in reported RV cases and a shift in proportion from G1P[8] to G2P[4] strains after introduction of RV vaccination in Scotland. The genotyping data from a subset of the total reported RV cases will be used to ascertain cross protection against strains and identify vaccine induced RV strain shifts in the years to come.     

用PCR方法检出蚤类携带巴尔通体

目的调查我国巴尔通体宿主动物体表寄生蚤类是否携带巴尔通体。方法2003年6～7月在云南省大理州云龙县居民区采集家猫、狗、鼠类等体表寄生蚤，用3对巴尔通体属特异性引物BhCS．781p—BhCS．1137n、Bh．311p—Bh．452n和TI1e．455p—TA1a．885n进行聚合酶链反应(PCR)，扩增巴尔通体gltA和16S～23S rRNA ITS中部分核酸片段，检测采集的蚤类是否感染巴尔通体。结果共采集251只寄生蚤，包括猫栉首蚤、人蚤、缓慢细蚤等7个常见蚤种，从1组猫栉首蚤和1组缓慢细蚤中扩增出目标带，证实有巴尔通体感染。结论猫栉首蚤和缓慢细蚤能够感染巴尔通体，是该种病原体的潜在传播媒介，间接表明当地家猫和鼠类动物存在巴尔通体感染。     

HCV的C/E1区PCR扩增方法的改进

目的通过对丙型肝炎病毒（HCV）基因组变异度较大的C/E1区兼并性引物的修改以提高该基因片段的扩增成功率,同时也为突变发生频繁的RNA病毒的核酸扩增提供方法上的借鉴。方法选用文献中针对C/E1区的多点兼并性引物（＂原引物＂）进行PCR扩增、测序,根据序列比对结果对原引物进行修改,没有突变的点进行去兼并还原,新突变点重新兼并,最终设计出特异性高适用性好的新引物。结果以44例HCV核酸阳性的艾滋病病毒（HIV）感染者为研究样本,原引物仅能成功扩增23例（52.3%）,而改进后的新引物能成功而高效的扩增40例（90.9%）。结论新引物能显著提高HCV核酸的检出率和扩增效率,为HCV的基因分型提供新的检测策略。     

婴儿巨细胞病毒感染的分子生物学诊断研究

目的评价婴儿巨细胞病毒感染中聚合酶链反应(PCR)加限制酶分析的应用价值.方法在巨细胞病毒(CMV)DNA多聚酶基因中设计一对引物,对CMV进行PCR扩增、分子克隆、序列分析后,选择BstUI进行酶切以鉴别扩增产物.结果巨细胞病毒PCR扩增后产物为592bp,经BstUI酶切后证实为CMVDNA,其最小检出量为0.1fg,与乙肝病毒、真菌、细菌和人类基因组无交叉反应.用该方法检测临床32份血和5份脑脊液标本中的CMV,12份血和1份脑脊液标本阳性;同时用ELISA法检测血标本,5例阳性.PCR阳性检出率为37.5%,ELISA为15.6%(P＜0.05).9例诊断为CMV感染患儿经更昔洛韦治疗10～14天后,复查外周血巨细胞病毒DNA,有1例仍为阳性.结论 PCR加限制酶分析能提高婴儿巨细胞病毒感染的诊断率.更昔洛韦可作为抗CMV感染的有效药物.     

中国部分地区新型肝炎病毒TTV感染的分子流行病学

目的了解我国部分地区新型肝炎病毒ＴＴＶ感染的分子流行病学、ＴＴＶ在人群中的感染分布状况,探讨ＴＴＶ在肝炎发病中的作用和地位。方法采用ＰＣＲ方法检测血清标本中ＴＴＶＤＮＡ,克隆测定不同地理株ＴＴＶ的部分基因序列,分析其基因变异情况。结果检测了南方（广东深圳和江苏南京）和北方（北京和辽宁沈阳）的１１２例非甲～非庚型肝炎病人,其中ＴＴＶＤＮＡ阳性者４８例,阳性率４２．９％,而１０２例甲～庚型肝炎病人中阳性率为２．９％（χ２＝４２．８,Ｐ＜０．０１）。ＡＬＴ异常而无甲～庚型肝炎病毒感染标志的献血员中,ＴＴＶＤＮＡ阳性率（３４６％）明显高于ＡＬＴ正常献血员的阳性率（１６．８％,χ２＝４．５,Ｐ＜０．０１）。南方株（广东深圳ＴＴＶＣＨＮ００２、南京ＴＴＶＮＡＮ００１）和北方株（北京ＴＴＶＳＨＢ０１５）病毒间同源性在９８％以上,日本发表的序列同源性也高于９７％。结论我国北方和南方地区均存在ＴＴＶ感染。ＴＴＶ感染与ＡＬＴ异常有极为密切的关系,可能是导致非甲～非庚型肝炎的重要病原。正常人群中存在ＴＴＶ感染者,类似于ＨＢｓＡｇ的所谓“慢性携带状态”。     

First report of a family outbreak of Chagas disease in French Guiana and posttreatment follow-up

The outbreak of acute Chagas disease due to oral transmission of the parasite is a well-known phenomenon mainly occurring in the Amazon. Such an event is described here for the first time in French Guiana. Eight patients of the same family, presenting epidemiological and clinical histories compatible with recent Trypanosoma cruzi infection of Chagas disease due to the ingestion of palm Oenocarpus bacaba juice were, rather late after the putative date of infection, underwent four parasitological and two serological specific tests for confirmation of the diagnosis. Real-time PCR results were positive for all the patients; strains were isolated by hemoculture from four patients, PCR identification of TcI DTU was made for six patients, while parasites were not detected in any of the patients by direct microscopic examination. The results of two serologic tests were positive. All patients were treated with benznidazole, and two patients were additionally given nifurtimox. A 6-year follow-up was possible for six patients. Real-time PCR was negative for these patients after 1 year, while the antibody rates decreased slowly and serology results were negative only after several years (1–5 years). Our findings confirm the occurrence of an outbreak of Chagas infection in members of the same family, with the oral mode of infection being the most likely hypothesis to explain this group of cases. Our results show the successful treatment of patients infected by TcI and the usefulness of real-time PCR for the emergency diagnosis of recent Chagas disease cases and in posttreatment follow-up.     

乙型肝炎分子流行病学分析

目的探讨乙型肝炎在患者及其子女间的遗传传递。方法对乙型肝炎患者３５个家系７４个个体，进行了血清游离型和外周血单核细胞内整合型ＨＢＶＤＮＡＵ５样序列片段和单链ＤＮＡ构象多态性等指标检测。结果男性患者及其病后出生的子女Ｕ５样序列检出率均显著高于其病前出生子女，差异有显著性；Ｕ５样序列检出率在乙型肝炎患者和该患者病后出生的子女呈一致性增高，可具有完全一致的单链泳动变位。男性患者病后出生子女的ＨＢｓＡｇ、ＨＢｅＡｇ、抗－ＨＢｃ阳性率和感染率均分别显著高于其病前出生子女，差异有显著性；男性患者的ＨＢｓＡｇ、ＨＢｅＡｇ、抗－ＨＢｃ阳性率与其病后出生子女呈一致性增高。结论从分子遗传学水平为乙型肝炎的遗传传递学说提供了证据。     

江苏省中部地区猪链球菌主要致病血清型分子流行病学调查

目的 了解江苏省中部地区正常猪群猪链球菌及主要致病血清型分布.方法 采集江苏省中部地区正常屠宰猪样本303份,用聚合酶链反应(PCR)法进行猪链球菌及主要致病血清型的检测,并对3株分离的猪链球菌菌株进行系统的生物学和分子遗传学鉴定.结果 303份猪标本中,2005年正常猪群中猪链球菌的携带率达88.0%,其中1(或14)型、2(或1/2)型、7型和9型携带率分别为9.6%、8.5%、11.3%、29.5%;2006年正常猪群中猪链球菌的携带率为82.5%,1(或14)型、2(或1/2)型、7型和9型携带率分别为17.6%、2.4%、25.8%、20.0%;3株分离菌株均为2型,2a毒力因子表现型为cps2+/gdh+/mrp-/epf-/sly-/fbps+/orf2+/89k-,2f、14e毒力因子表现型均为cps2+/gdh+/mrp-/epf-/sly-/fbps-/orf2-/89k-;3株分离菌株对阿莫西林、氨苄西林、青霉素等高度敏感,但对阿米卡星和四环素有显著的耐药性;对BALB/c小鼠和家兔无明显致病性.结论 江苏省中部地区正常猪群中猪链球菌携带率处于较高水平,多种血清型同时存在,毒力因子表型与流行毒力株有显著差异.     

Underestimation of snakebite mortality by hospital statistics in the Monaragala District of Sri Lanka

Estimates of snakebite mortality are mostly based on hospital data, although these may considerably underestimate the problem. In order to determine the accuracy of hospital-based statistics, data on snakebite mortality in all hospitals in the Monaragala District of Sri Lanka were compared to data on snakebite as the certified cause of death for the district, for the 5-year period between 1999 and 2003. Data were cross-checked in a sample of hospitals and divisional secretariats within the district. Hospital statistics did not report 45 (62.5%) of the true number of snakebite deaths in the Monaragala District. Twenty-six (36.1%) of the victims either did not seek, or had no access to, a hospital. Another 19 (26.4%) had arrived at hospital, but had done so too late to receive treatment. Our study confirms the limitations of official hospital-based mortality data on snakebite.