浙江省首次发现新型布尼亚病毒感染病例及分离病毒分子鉴定

目的 了解浙江省是否存在新型布尼亚病毒潜在自然疫源地,分离疑似病例血清中新型布尼亚病毒并进行鉴定.方法 免疫荧光法检测浙江省台州地区野生啮齿动物不同组织标本中新型布尼亚病毒抗原.实时荧光定量RT-PCR检测疑似病人血清中新型布尼亚病毒核酸,扩增产物进行序列测定.Vero细胞分离疑似病人血清中新型布尼亚病毒,以新型布尼亚病毒株核衣壳蛋白编码基因为靶基因,采用RT-PCR及扩增产物测序对分离的疑似新型布尼亚病毒株进行鉴定,另对该序列进行同源性分析和比较.结果 70只野生啮齿动物中,免疫荧光法检测阳性率为5.71%.实时荧光定量RT-PCR检测结果显示,4例疑似病人血清中有两例检测结果阳性.1例阳性血清样本中分离出1株疑似新型布尼亚病毒,RT-PCR和测序结果证实该病毒确为新型布尼亚病毒,其核衣壳蛋白编码基因序列与湖北省新型布尼亚病毒分离株相似性高达92.2%,但与国内其他地区新型布尼亚病毒分离株序列差异较大.结论 首次证实浙江省存在新型布尼亚病毒自然疫源地及感染病人,不同群新型布尼亚病毒分布可能存在一定的地理差异.     

我国中东部地区蜱中斑点热群立克次体与新型布尼亚病毒复合感染调查研究

为了验证我国中东部发热伴血小板减少综合征流行地区—信阳和济南的蜱中有斑点热群立克次体存在,且有复合感染新型布尼亚病毒的情况,用布旗法和动物体表检查法在河南省信阳市和山东省济南市捕获蜱,采用PCR和RT-RCR进行病原体感染筛查.信阳市捕获长角血蜱215只,其中游离蜱164只,寄生蜱51只.37只蜱斑点热群立克次体检测阳性,阳性率17.2％;38只蜱新型布尼亚病毒检测阳性,阳性率为17.7％;4只蜱斑点热群立克次体与新型布尼亚病毒复合感染,复合感染率为1.9％.山东省捕捉到166只寄生蜱,均为长角血蜱,4只蜱斑点热群立克次体检测阳性,阳性率为2.4％.6只蜱新型布尼亚病毒检测阳性,阳性率为3.6％:2只蜱为斑点热立克次体与新型布尼亚病毒复合感染,复合感染率为1.2％.结果证实我国中东部地区存在斑点热立克次体与新型布尼亚病毒复合感染.     

发热伴血小板减少综合征布尼亚病毒实时荧光RT-PCR检测方法的建立

目的 建立新型发热伴血小板减少综合征布尼亚病毒的TaqMan探针实时荧光RTPCR检测方法并进行评估,为发热伴血小板减少综合征监测中新型布尼亚病毒感染的排查提供实验室检测依据.方法 利用新型布尼亚病毒S片段基因的特异性序列设计引物和探针,探针5'端标记FAM,3'端标记TAMRA,优化反应体系与反应条件,并对不同浓度含...     

血清学方法和实时荧光定量PCR方法在新型布尼亚病毒检测中的应用研究

目的探讨血清学检测方法和实时荧光定量PCR方法在新型布尼亚病毒检测中的应用。方法连续采集烟台地区莱州、蓬莱疑似发热伴血小板减少综合征患者血清,分别用胶体金实验方法、ELISA实验方法检测抗新型布尼亚病毒IgM抗体,实时荧光定量PCR方法检测新型布尼亚病毒核酸,SPSS18．0统计结果。结果胶体金方法和ELISA方法检测结果总符合率为96．67％,一致性KAPPA检验K系数为0．933;胶体金方法和实时荧光定量PCR方法检测结果均受病程影响（两者P值均小于0．05）;实时荧光定量PCR2疗法检测不受年龄、性别影响（P均〉0．05）。结论新型布尼亚病毒检测发病12天以前推荐使用实时荧光定量PCR方法,发病16天以后,可使用血清学方法检测抗新型布尼亚病毒IgM抗体。     

蜱携带重要人畜共患病毒研究概况

蜱能够传播多种病毒,已知有6个病毒科的病毒能通过蜱虫吸血传播,分别是黄病毒科、布尼亚病毒科、正粘病毒科、弹状病毒科、呼肠孤病毒科和非洲猪瘟病毒科。除非洲猪瘟病毒科外,其余病毒均为核糖核酸(RNA)病毒。黄病毒科和布尼亚病毒科病毒可在人类引起脑炎和出血热,因此其意义尤为重要。森林脑炎病毒、波瓦生病毒和克里米亚—刚果热病毒等蜱传病毒引起的人畜共患疾病,近年来在世界上多个地区重新流行。新型蜱传病毒及相关病例不断被发现,例如我国发现的发热伴血小板减少综合征病毒(SFTSV)以及国外发现的Heartland和波本(Bourbon)病毒等,引起了医学界的广泛重视。随着人类对自然资源的开发,与自然界蜱的接触机会日益增加,导致蜱传病毒性疾病的发病率上升。为了做好及时应对这种潜在公共健康威胁的准备,本文对蜱及其携带的重要病毒特点进行了综述。     

两例重症新型布尼亚病毒感染患者的临床特征及病原学研究

报道了2例重症发热伴血小板减少(SFTS)感染病例,2名患者均具有典型的SFTS布尼亚病毒(SFTSV)感染临床症状,以发热、腹泻为首发症状,血小板呈进行性降低。2例新布尼亚病毒S片段核酸阳性,其中从1例患者血液标本中分离出病毒,对病毒进行体外培养并在电镜下观察到病毒颗粒。通过测序拼接得到病毒的S片段,S片段的进化树分析表明此毒株属于新布尼亚病毒C基因型C1分支,与安徽毒株(JQ670933.1)基因同源性最高,达到99.5%,具有明显的地域性特点。本文得到的S片段有10个碱基突变,并全部导致了氨基酸改变,其中6个突变位于NP基因,4个突变位于NSs基因。分离毒株表明SFTSV在安徽沿长江流域散发存在且毒株序列有相应变化,但病原学特征没有明显改变。     

烟台市新型布尼亚病毒致发热伴血小板减少综合征12例临床分析

近年来,我国山东、河南、安徽等地区发现一些发热伴血小板减少为主要临床表现的患者.根据中国疾病预防控制中心的研究结果,新型布尼亚病毒可能是发热伴血小板减少综合征的主要致病原[1].     

我国吸血库蠓中Tete病毒组病毒的首次分离与鉴定

中国已从自然界采集的蚊虫标本中分离出多株正布尼亚病毒, 包括Simbu血清群的Cat Que、曼扎尼拉和阿卡斑病毒, 以及加利福尼亚血清群的Tahyna病毒。但自20世纪80年代以来, 还未从蚊虫以外的吸血节肢动物中分离出正布尼亚属的病毒。在本研究中, JXLC1806-2病毒于2018年夏天从中国东部江西省黎川县采集的库蠓中分离, 该病毒分离物在接种哺乳动物细胞(BHK-21)48小时内显示出显著的细胞病变作用, 病毒滴度为1×105.6 pfu/mL。JXLC1806-2病毒不仅在哺乳动物细胞中引起CPE, 而且在乳鼠中也可引起发病和死亡, 但在C6/36细胞中不引起CPE, 并且RT-PCR未检测到复制, 提示该病毒为动物病毒。核苷酸和氨基酸序列分析表明, JXLC1806-2病毒基因组由S、M和L三个片段组成。系统发育分析表明, JXLC1806-2病毒的S、M和L基因属于正布尼亚病毒属Tete病毒组, 但与Tete血清组的其他成员形成了独立的进化支。结果表明, JXLC1806-2病毒为Tete病毒组的一个新成员, 命名为Lichuan病毒, 这是中国首次分离到Tete病毒组...     

发热伴血小板减少综合征病毒在巨噬细胞中的亚细胞定位

目的 发热伴血小板减少综合征病毒(SFTSV)是新发传染病发热伴血小板减少综合征的致病病原,为布尼亚病毒科白蛉病毒属一种新型病毒.通过研究发热伴血小板减少综合征病毒在巨噬细胞中的亚细胞定位,了解SFTSV在细胞内的复制组装机制.方法 应用两种人源巨噬细胞系THP-1细胞和U937细胞,通过免疫荧光共聚焦方法分析SFTSV感染巨噬细胞后与高尔基体和内质网的共定位.结果 SFTSV可特异性感染巨噬细胞,在SFTSV感染的巨噬细胞中SFTSV核蛋白与高尔基体共定位于核周,与内质网紧密相邻,但没有共定位.结论 在SFTSV感染的巨噬细胞中,内质网和高尔基体可能是病毒进行加工修饰及包装成熟的重要场所.     

MxA蛋白研究进展

MxA蛋白是Ⅰ型干扰素(α/β)诱导产生的分布于细胞质中的蛋白质,具有广谱的抗病毒活性,对粘液病毒、副粘液病毒、布尼亚病毒、棒状病毒、囊膜(外衣)病毒、小RNA病毒及乙肝病毒均有敏感的抗病毒活性.本文论述了MxA蛋白的结构和抗病毒机制的最新研究进展,以及MxA蛋白表达与肾综合症出血热、红斑狼疮等疾病的发生、发展之间的关系,并揭示了MxA基因的单核苷酸多态性在慢性肝炎患者对干扰素治疗反应性的机制中起重要作用,并可做为一个可靠的预测因子.     

Detection of Crimean-Congo hemorrhagic fever virus RNA in the hyalomma marginatum ticks taken from bitten people

Among 1076 imagoes of the Hyalomma marginatum ticks taken from bitten people in the Astrakhan Region in 2006-2010, 10 (0.9%) ticks contained Crimean-Congo hemorrhagic fever (CCHF) virus RNA, as evidenced by RT-PCR. The diagnosis of CCHF was made on the basis of clinical data and the results of examination of sera in RT-PCR, ELISA-IgM, and ELISA-IgA in three of the 10 persons bitten by infected ticks. Two more patients were observed to have acute febrile diseases, but their sera were not examined in RT-PCR and ELISA, so their etiological association with CCHF virus RNA was not reliably established.     

Molecular evidence for potential transovarial transmission of Jingmen tick virus in Haemaphysalis longicornis fed on cattle from Yunnan Province,China

Jingmen tick virus (JMTV) is a novel tick-borne virus first identified from Jingmen city, Hubei Province of China in 2010. It has been proved that JMTV can cause human diseases and is widely distributed both inside and outside of China. However, the survival mode and transmission characteristics of JMTV still need further research, particularly in terms of transovarial transmission. In this study, an investigation was conducted to explore the presence of JMTV from engorged female ticks to their offspring. All engorged female adult ticks were collected from domestic cattle and allowed to lay eggs in appropriate humidity and temperature conditions. Maternal ticks, eggs and larvae were screened for JMTV RNA through real-time polymerase chain reaction (RT-PCR) and nested PCR methods. The results revealed the positive rate of 10.53% (10/95) in engorged ticks, 9.09% (2/22) in eggs and 8% (4/50) in larvae pools, respectively. Phylogenetic analysis confirmed that sequences from eggs and larvae had closer relationship with those isolates from maternal engorged ticks with more than 99.7% homology and JMTV manifested with evolutional conservatism. Our study has identified for the first time that JMTV could be transmitted from mother generation to offspring of Haemaphysalis Longicornis. Nonetheless, the efficiency of transovarial transmission in JMTV and the significance of ticks as amplification hosts still need to be further illustrated.     

2001-2010年广州市肾综合征出血热监测分析

目的通过分析2001-2010年监测资料,研究广州市肾综合征出血热（HFRS）的流行特征和变化趋势。方法应用描述性流行病学方法分析人间疫情监测、宿主动物监测资料,实验室应用间接免疫荧光法检测鼠血清HV特异性IgG抗体,直接免疫荧光法检测鼠肺汉坦病毒（HV）抗原。结果 2001-2010年共报告HFRS743例,死亡4例,发病率为0.81/10万,病死率为0.54%。发病人数和发病率呈现上升趋势,发病高峰在10月至次年6月,病例集中在天河区、海珠区和白云区,职业分布以工人、家务及待业、商业服务为主,其次是民工和农民。男女比例为3.10∶1,年龄集中在20～50岁。鼠密度为9.64%,鼠血清HV特异性IgG抗体阳性率为4.94%,鼠肺HV抗原阳性率为5.56%。鼠密度和鼠种构成相对稳定,但2004-2010年鼠血清HV特异性IgG抗体阳性率和鼠肺HV抗原阳性率均处于持续上升趋势。鼠种构成主要以褐家鼠（70.01%）为主,其血清HV特异性IgG抗体阳性率（6.02%）和肺HV抗原阳性率（6.58%）在各鼠种中最高。结论广州市HFRS疫情呈现一定的上升趋势,发病风险不断增大,应加强预防控制工作;另外,广州市可能已经由家鼠型疫区演变为混合型疫区,应寻找进一步的相关证据。     

Microclimate and the zoonotic cycle of tick-borne encephalitis virus in Switzerland

The focal distribution of tick-borne encephalitis virus (TBEV; Flaviviridae, Flavivirus) appears to depend mainly on cofeeding transmission between infected Ixodes ricinus L. nymphs and uninfected larvae. To better understand the role of cofeeding ticks in the transmission of TBEV, we investigated tick infestation of rodents and the influence of microclimate on the seasonality of questing I. ricinus ticks. A 3-yr study was carried out at four sites, including two confirmed TBEV foci. Free-living ticks and rodents were collected monthly, and microclimatic data were recorded. A decrease in questing nymph density was observed in 2007, associated with low relative humidity and high temperatures in spring. One site, Thun, did not show this decrease, probably because of microclimatic conditions in spring that favored the questing nymph population. During the same year, the proportion of rodents carrying cofeeding ticks was lower at sites where the questing nymph density decreased, although the proportion of infested hosts was similar among years. TBEV was detected in 0.1% of questing ticks, and in 8.6 and 50.0% of larval ticks feeding on two rodents. TBEV was detected at all but one site, where the proportion of hosts with cofeeding ticks was the lowest. The proportion of hosts with cofeeding ticks seemed to be one of the factors that distinguished a TBEV focus from a non-TBEV focus. The enzootic cycle of TBEV might be disrupted when dry and hot springs occur during consecutive years.     

ELISA and RT-PCR-based research of viruses in the ticks collected in the foci of Crimean-Congo fever in Kazakhstan and Tajikistan in 2001-2002

Different species of ticks were found, in the territories of Kazakhstan and Tajikistan, to be infected with the virus of Crimean-Congo hemorrhagic fever (CKHF). The virologic evaluation included determination of antigen and RNA of the CKHF virus by ELISA and RT-PCR, respectively. The below tick species were found to be involved in the epidemic process: Hyalomma asiaticum, Dermacentor niveus (Kazakhastan) and Hyalomma anatolicum (Tajikistan). The results testify to the fact that Hyalomma ticks are the main carrier of the above virus in the Middle Asia. At the same time, Dermacentor niveus ticks are infection carriers in Kazakhstan.     

Serological evidence of tick-borne encephalitis virus infection in rodents captured at four sites in Switzerland

In a previous study, the presence of tick-borne encephalitis virus (TBEV) in questing Ixodes ricinus L. ticks and in field derived ticks that engorged on small mammals (n = 9,986) was investigated at four sites located in a TBE area in Switzerland. Two of these sites were already recognized as TBE foci (Thun and Belp) and the screening of ticks revealed the presence of TBEV in ticks at a third site, Kiesen, but not at the fourth one, Trimstein. The aim here was to test another approach to detect TBE endemic areas. Sera from 333 small mammals (Apodemus flavicollis, A. sylvaticus, Myodes glareolus) captured in 2006 and 2007 at the four sites were examined for the presence of antibodies against TBEV using immunofluorescence and avidity tests. Overall the prevalence of antibodies against TBEV in rodents reached 3.6% (12/333). At two sites known as TBE foci, Thun and Belp, anti-TBEV antibodies were detected in 9.9% (9/91) and 1.6% (1/63) of rodent sera, respectively. At the third site, Kiesen, recently identified as a TBE focus by the detection of TBEV in ticks, anti-TBEV antibodies were detected in 1.8% (2/113) of rodent sera. Finally, at Trimstein, none of the examined rodent sera had antibodies against TBEV (0/66). This study shows another approach to detect TBE foci by testing antibodies in small mammal sera that is less time-consuming and less expensive than molecular tools.     

Venezuelan equine encephalomyelitis virus infection in and transmission by the tick Amblyomma cajennense (Arachnida: Ixodidae)

To assess a possible role of ticks as the maintenance host for epizootic strains of Venezuelan equine encephalomyelitis (VEE) virus, laboratory experiments were conducted to determine if ticks could become infected, maintain, and transmit the virus. Larval and nymphal Amblyomma cajennense (F.) and larval Dermacentor nitens Neumann ticks were exposed to epizootic VEE virus (Trinidad donkey strain) by allowing them to feed on viremic guinea pigs (strain 13). In A. cajennense, transstadial transmission was observed from larvae to nymphs and adults. Horizontal viral transmission to a mammalian host was accomplished by nymphs. Infection rates in nymphs and adults were 2% (42/2,750) and 4% (9/244), respectively, afer ingestion of virus as larvae. Virus was detected in A. cajennense adult ticks for up to 171 d after infection in the larval stage. A cajennense, exposed as nymphs, ingested virus but did not become infected (0/164 after 10 d after taking an infective bloodmeal). No virus was detected in D. nitens 7 d after exposure. These findings suggest that A. cajennense potentially could be involved in an interepizootic maintenance cycle of epizootic VEE viral strains.     

Distribution of 'Ehrlichia walkeri' in Ixodes ricinus (Acari: Ixodidae) from the northern part of Italy

The prevalence of 'Ehrlichia walkeri' in Ixodes ricinus in northern Italy was studied. A total of 456 ticks were collected from seven places around Belluno, and 292 living ticks were examined using polymerase chain reaction (PCR). Nineteen ticks were positive for gltA of 'E. walkeri', and the prevalence rate for each place ranged from 0 to 12.8%. The disparity of prevalence rates among areas examined suggests that 'E. walkeri' is not widespread in ticks and requires an animal host for its maintenance in nature.