Echinococcus multilocularis infection in pet dogs in Japan

A survey of Echinococcus multilocularis infections in pet dogs in Japan from 1997 to 2007 was conducted by testing for coproantigen reactivity, fecal taeniid eggs, and egg DNA. In Hokkaido, the only island where E. multilocularis is endemic in Japan, 18 of 4768 dogs (0.4%) excreted taeniid eggs that were positive for E. multilocularis DNA by polymerase chain reaction (PCR). Most of the dogs testing positive for egg DNA were kept free-range, but three dogs had been kept inside their owners' houses. In addition, 15 dogs were suspected to be infected based on the results of a coproantigen test. One dog, which was transported from Hokkaido to Honshu, the main island of Japan, was excreting taeniid eggs that were positive for E. multilocularis DNA by PCR. These results suggest the importance of proper pet management in disease prevention, even for dogs kept indoors, and they point out a possible means by which the parasite may be introduced into non-endemic areas through transport of infected dogs.     

Short report: Echinococcus multilocularis confirmed on Kunashiri Island, 15 kilometers from the eastern part of Hokkaido, Japan

There are two foci of alveolar echinococcosis (AE) caused by Echinococcus multilocularis in Japan. The first focus is on Rebun Island where AE patients were found from 1937, and the second is in eastern Hokkaido where patients have been found since the 1960s. The origin of the second focus is unknown. To further investigate AE in eastern Hokkaido, wild rodents (Muridae) were captured and examined for infection on Kunashiri Island, which is located 15 km off the northeastern coast of Hokkaido. Metacestodes of E. multilocularis were isolated from two of 31 voles, all of which were identified to be Clethrionomys rufocanus. Mitochondrial DNA sequencing data of recovered cestodes showed total identity with the cestode reported from Hokkaido. These results suggest that E. multilocularis may have been introduced to Hokkaido from Kunashiri Island during or after 1965.     

Equine Getah virus infection: isolation of the virus from racehorses during an enzootic in Japan

A primary enzootic of equine Getah virus infection involving 722 of 1,903 racehorses occurred at a training center in Japan between September and November of 1978. Sixty-two viral agents were isolated from the plasma of 209 sick horses which exhibited pyrexia with rectal temperatures ranging from 38.5--40 degrees C, urticarial rash on various portions of the body, and edema of the hind legs. The viruses were antigenically related to the AMM 2021, Haruna, and Sagiyama strains of Getah virus. Infection and disease were produced experimentally in horses when inoculated by the intramuscular or intranasal routes.     

犬体内细粒棘球绦虫和多房棘球绦虫的混合感染

目的 证实家犬体内是否存在细粒棘球绦虫和多房棘球绦虫混合感染。方法 从新疆和静县巴音布鲁克草原现场收购的30条牧羊犬,经麻醉后处死解剖,在1只雌性牧羊犬小肠内发现棘球绦虫成虫1万条以上,经显微镜观察,疑为细粒棘球绦虫和多房棘球绦虫混合感染。用Eg1f/r和EM-15/17EM引物分别对两种棘球绦虫的线粒体DNA特异目的片段进行序列分析鉴定。结果 形态学观察:细粒棘球绦虫孕节长大,生殖孔偏后,位于节片一侧中部。子宫有不规则的分支和侧突(侧囊),内含虫卵200~800个。多房棘球绦虫较短小,4~5体节。孕节中子宫呈简单的囊状,无侧囊。生殖孔开口于侧缘的前半部。线粒体12S RNA序列鉴定,扩增样本DNA经同源序列比较发现,与细粒棘球绦虫G1型具有相同的序列;扩增样本与多房棘球绦虫具有相同的序列。分别确定为细粒棘球绦虫和多房棘球绦虫两种虫种。结论 首次证实家犬体内存在细粒棘球绦虫和多房棘球绦虫的混合感染。     

Purification and characterization of a specific antigen from Echinococcus multilocularis

A polypeptide (Em2a) purified by affinity chromatography from the Echinococcus multilocularis metacestode showed a high degree of purity as assayed by SDS-PAGE and analytical isoelectrical focusing. A minor contamination with host albumin was revealed. Estimation of relative mol. mass gave a value of 54,000. The isoelectric point was found to be 4.8. Antigenic activity of the polypeptide was demonstrated by immunoprecipitation and western blotting. In these assays the protein was recognized only by homologous sera from patients infected with larval E. multilocularis. This antigen (Em2a) did not react in the ELISA with sera from patients infected with heterologous helminths; these sera were highly cross-reacting with antigen from E. granulosus hydatid fluid. Seventy-three (94%) from 78 investigated patients (alveolar echinococcosis) showed a seropositive reaction with the polypeptide Em2a.     

Modelling the spatial distribution of Echinococcus multilocularis infection in foxes

Alveolar echinococcosis is a rare but fatal disease in humans and is caused by the fox tapeworm Echinococcus multilocularis. The densities of fox and grassland rodent populations and the interactions between them influence E. multilocularis transmission rates in Europe. Successful rabies control has caused fox populations and E. multilocularis prevalence rates to increase in many European countries. The potential increase of the infection pressure on the human population motivates the monitoring of the infection status of foxes over space and time. Detection of E. multilocularis antigen levels in fox faecal samples collected in the field might provide a pragmatic methodology for epidemiological surveillance of the infection status in wildlife hosts across large areas, as well as providing an indication of the spatial distribution of infected faeces contaminating the environment. In this paper, a spatial analysis of antigen levels detected in faeces collected in the Franche-Comté region of eastern France is presented. In Franche-Comté, rodent outbreaks have been observed to originate in areas rich in grassland. Spatial trends in fox infection levels were modelled here as a function of the composition ratio of grassland in the landscape derived from the CORINE land-cover map. Kriging models incorporating the grassland trend term were compared to a variety of models in which five alternative trend expressions were used: the alternative trend expressions included linear and quadratic polynomials on the x and y coordinates with and without a grassland term, and a constant mean model. Leave-one-out cross-validation indicated that the estimation errors of kriging with a trend models were significantly lower when the trend expression contained the grassland index term only. The relationship between observed and predicted antigen levels was strongest when the estimated range of autocorrelation was within the home range size of a single fox. The over-dispersion of E. multilocularis in foxes may therefore account for the majority of spatial autocorrelation locally, while regional trends can be successfully modelled as a function of habitat availability for intermediate hosts.     

巢式PCR在鉴别多房棘球绦虫及细粒棘球绦虫基因亚型中的应用

目的 探索巢式PCR在鉴别多房棘球绦虫及细粒棘球绦虫基因亚型中的应用价值.方法 将水泡带绦虫、犬弓首蛔虫、多房棘球绦虫、细粒棘球绦虫羊株和骆驼株等样本的DNA用巢式PCR扩增.结果 巢式PCR可以扩增出多房棘球绦虫和水泡带绦虫,而对细粒棘球绦虫羊株和骆驼株及其他寄生虫均不能扩增出.结论 在鉴别细粒棘球绦虫和多房棘球绦虫方面,巢式PCR有一定的诊断意义,但不能用于鉴别细粒棘球绦虫基因亚型.     

甘肃省合作牦牛自然感染多房棘球蚴的调查

本文报告甘肃合作牦牛自然感染多房棘球蚴，感染率１．６％。病理学观察，多房棘球蚴发育不良，无生发层与原头节存在，与人体多房棘球蚴病理观察相似。     

新疆北部多房棘球绦虫动物宿主研究初报

本文报告在新疆北部泡型包虫病流行地区的农村牧区以及山地和草原地带进行多房棘球绦虫终宿主和中间宿主调查的结果。采用槟榔碱导泻法检查 30 5只家 (牧 )犬 ,在 5 2只犬中检出棘球绦虫成虫 ,感染率为 17%。对所获 13974条虫体进行鉴定的结果 ,皆为细粒棘球绦虫。表明在新疆北部泡型包虫病流行地区 ,家犬不是多房棘球绦虫的终宿主。检查啮齿目动物 31种 5 16 3只 ,食虫目动物 4种 2 6 1只和兔形目动物 2种 196只。在西部天山地区捕获的伊犁田鼠和塔尔巴哈台山地区捕获的水鼠平中发现多房棘球蚴感染 ,表明这两种鼠类是当地多房棘球绦虫的中间宿主。属于国内新记录。     

小鼠感染泡球蚴后细胞因子水平的变化

目的　观察人工接种泡球蚴(EM)昆明小鼠体内6种细胞因子水平的动态变化,研究泡球蚴病的免疫学机制。　方法　实验组和对照组小鼠分别腹腔接种泡球蚴及生理盐水,持续观察260d,收集各组血清用ELISA法检测血清中白细胞介素2(IL2)、γ干扰素 (IFNγ)、肿瘤坏死因子α(TNFα)、IL4、IL5、IL10水平。　结果　实验组6种细胞因子水平始终高于正常对照组,其中辅助性T细胞1(Th1)类细胞因子IL2水平在感染后 80d达到峰值,感染140d后迅速降低;TNFα水平在感染后40d较对照组明显上升,感染100d左右达到峰值,140d后迅速下降;IFNγ在感染80d后达到峰值,140d后缓慢下降;而在80d以前,辅助性T细胞2(Th2)类细胞因子IL4、IL5、IL10维持在较低水平;100d后,这3类细胞因子明显上升,其中IL4、IL10水平在100d达到峰值,IL5水平在140d达到峰值,以后维持在较高水平。　结论　Th2细胞介导的体液免疫与Th1细胞介导的细胞免疫共同参与了宿主抗棘球蚴免疫。感染早期以Th1细胞介导的细胞免疫应答为主,感染中晚期转化为以Th2细胞介导的体液免疫为主。     

青海省多房棘球绦虫分子种系发生研究

目的　对青海省多房棘球绦虫分离株Cox1、Nad1基因进行扩增和测序,并构建系统进化树及分子钟,为推测其进化关系及起源提供参考依据。方法　收集2017年青海省人民医院收治的22份肝多房棘球蚴病患者术后标本,对多房棘球蚴线粒体DNA Cox1、Nad1基因进行PCR扩增和测序,并与GenBank数据库中的棘球属绦虫Cox1基因和Nad1基因序列进行比对,观察种内变异情况并构建进化树和分子钟。结果　所有多房棘球绦虫标本与GenBank数据库中检索的多房棘球绦虫亚洲株Cox1、Nad1基因序列同源性均达99%以上,共获得6种不同基因型,其中有2个分离株在GenBank数据库中未找到同源性100%的基因序列。系统进化树显示,收集的多房棘球绦虫标本与多房棘球绦虫亚洲株聚类效果明显;分子钟推测青海地区多房棘球绦虫起源于9.4万年前。结论　本研究发现青海省多房棘球绦虫存在6种不同基因型,其中首次发现2种基因型。青海地区多房棘球绦虫优势株为亚洲株,起源时间约在9.4万年前。     

灰仓鼠和草原兔尾鼠感染细粒棘球蚴和多房棘球蚴的实验研究

用细粒棘球蚴（Ｅｃｈｉｎｏｃｏｃｃｕｓ ｇｒａｎｕｌｏｓｕｓ）原头节和多房棘球蚴（Ｅｃｈｉｎｏｃｏｃｃｕｓ ｍｕｌｔｉｌｏｃｕｌａｒｉｓ）原头节实验感染灰仓鼠（Ｃｒｉｃｅｔｕｌｕｓ ｍｉｇｒａｔｏｒｉｕｓ）和草原兔尾鼠（Ｌａｇｕｒｕｓ ｌａｇｕｒｕｓ）,并以ＮＩＨ小鼠和ＢＡＬＢ／ｃ小鼠做对照,观察了继发性棘球蚴囊的发育情况。四种鼠的细粒棘球幼感染率分别为３１％（３７／１１８）、２１％（６／２８）、