新疆塔城地区多房棘球蚴的鼠类宿主考察

1989～1991年由新疆的塔城、裕民、额敏和托里等4个县市采集各类鼠类4科11属14种共9832只。剖检结果发现有0.014％(1/6980)小家鼠(Mus musculus)和0.09％(2/2211)赤颊黄鼠(Citellus erythrogenys)自然感染多房棘球蚴。二者发育的多房棘球蚴均系不育囊,囊内没有原头节。小家鼠和赤颊黄鼠均是本虫在我国的鼠类宿主新记录,而赤颊黄鼠又是本虫鼠类宿主的首次报道。     

新疆塔城地区和布克塞尔县赤颊黄鼠腹腔接种多房棘球蚴的实验观察

中英法三国包虫病研究项目小组在欧共体ＥＥＣ－ＳＴＤ３项目，中法科学技术友好促进会支持下，于１９９６年在新疆和布克塞布县进行了包虫病流行病学及生态学研究，将现场捕捉野鼠一赤颊黄鼠带回新疆医学院作多房棘球蚴感染敏感性实验，感染率功率达８０％，说明赤颊黄鼠对多房棘球蚴高度敏感。有可能在塔城，阿勒泰地区的多房棘球蚴病流行中起重要作用。     

Ecological epidemiology: landscape metrics and human alveolar echinococossis

The larval form of the fox tapeworm Echinococcus multilocularis can cause a potentially fatal liver infection in human hosts. Globally rare, the disease has a high prevalence focus in western China. Recent research has linked landscape to the presence and prevalence of the disease. This paper discusses the epidemiology of E. multilocularis in terms of landscape and disease transmission ecology. Landscape form was defined using satellite imagery to create a land cover classification for a study site in Zhang County (Gansu Province, China). Following the analysis of many landscape metrics, mean shape index was found to be related to the prevalence of infection for 31 villages in 1975 and 1997, at two spatial intervals, suggesting that habitat form is a correlate of disease. A temporal difference shows that the landscape is no longer suitable for transmission. These results indicate the possibility of identifying future hotspots which could aid the management of the disease.     

Dual infection of animal hosts with different Echinococcus species in the eastern Qinghai-Tibet plateau region of China

The eastern Qinghai-Tibet plateau of China is a highly endemic region of echinococcosis where Echinococcus granulosus sensu stricto (sheep strain), Echinococcus multilocularis, and Echinococcus shiquicus are distributed sympatrically. We developed a polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) method for the identification of the three species in this region. The PCR-RFLP showed the dual infection of animals with different Echinococcus spp. The first case was a domestic dog concurrently infected with adults of E. granulosus and E. multilocularis. The second case was a plateau pika (Ochotona curzoniae) harboring metacestodes of E. multilocularis and E. shiquicus in the liver. The high susceptibility of some mammalian hosts to the parasites and the high prevalence of the three co-endemic species probably increase the chance of mixed infections in the eastern Tibetan plateau.     

Echinococcus multilocularis

PURPOSE OF REVIEW: Echinococcus multilocularis is a tapeworm of foxes that may cause a zoonotic infection resulting in a highly pathogenic and potentially fatal chronic liver infestation called human alveolar echinococcosis. Radical liver resection currently offers the only potential cure. Although alveolar echinococcosis is a rare parasitic disease that is restricted to transmission in the northern hemisphere, the parasite is geographically widespread being distributed from Alaska, across Canada and north central USA, through northern Europe and Eurasia to Japan. The present review summarizes the background to this helminthic infection and recent contributions in areas of pathology, diagnosis, treatment and transmission. RECENT FINDINGS: Concern is growing in Europe that the prevalence and distribution of E. multilocularis in red foxes has increased significantly in the last 10-15 years. A retrospective analysis revealed >550 cases of human alveolar echinococcosis diagnosed between 1982-2000, with the majority in France, Germany and Switzerland. Human prevalence rates >3% occur in central northwest China and the disease is of public health concern in northern Japan. Improvements in immunodiagnosis with native and recombinant antigens have enabled more accurate confirmation of hepatic image findings, while development of in-vitro culture of metacestode tissues provides a useful model for screening new anti-alveolar echinococcosis drugs as alternatives to albendazole and surgery. Recombinant molecules from the oncosphere and metacestode stages have shown potential as vaccine candidates. New tools of coproantigen and copro-DNA detection for vulpine infections have proved highly beneficial in epidemiological and transmission ecology studies, as has a landscape ecology approach to develop risk models for communities in endemic areas. SUMMARY: It is possible that human AE will become an emergent zoonosis in some regions of Europe and Eurasia. Improvements in diagnostic and treatment approaches are being investigated. Further understanding of host immune responses will aid in characterization of disease pathology. Control of E. multilocularis in its natural cycles will be difficult due to the involvement of wild animal hosts, however use of anthelminthic baits and dosing of domestic dogs may reduce transmission at local scales.     

Copro-diagnosis of Echinococcus granulosus infection in dogs by amplification of a newly identified repeated DNA sequence

Diagnosis of Echinococcus granulosus infection in dogs by detecting adult worms recovered post mortem or purged from the intestines after treatment with arecoline is not suitable for mass screening. Large-scale diagnosis by detection of copro-antigens is useful but only with relatively high intensity infections, and only by genus. To provide a more sensitive and specific diagnosis, a polymerase chain reaction (PCR) assay was developed, that amplified a target repeated sequence (EgG1 Hae III) newly identified in the genome of the common sheep strain of E. granulosus. This repeated sequence consists of approximately 6,900 copies, arranged in tandem, in groups of 2-6 repeats. The corresponding primers used in the PCR easily detected a single egg with no cross-amplification of DNA from closely related cestodes, including E. multilocularis and Taenia spp. Fecal samples from naturally infected dogs, with 2-10,000 E. granulosus worms at necropsy, were all PCR positive, while E. multilocularis or Taenia spp. positive controls as well as non-endemic controls were all PCR negative. This copro-PCR assay was demonstrated to be 100% specific and also detected all necropsy-positive E. granulosus-infected dogs. It is suggested that this copro-PCR assay has the potential for pre-mortem diagnosis of E. granulosus infection even in areas where E. granulosus and E. multilocularis are co-endemic.     

Serological prevalence of echinococcosis and risk factors for infection among children in rural communities of southern Ningxia, China

Objective  To assess the usefulness of serology as an indicator of Echinococcus transmission for developing preventive measures against echinococcosis in rural communities.
Methods  Cross-sectional survey in 2002 among 861 children aged 7 to 18 years in Xiji County, Ningxia, China. Before ultrasound abdominal examination, a questionnaire was used to identify socioeconomic, sanitary and hygiene risk factors for echinococcal infection; filter paper blood samples were collected from each child for specific antibody detection using EmP ( Echinococcus multilocularis ) and EgB ( Echinococcus granulosus ) antigens.
Results  Transmission of both E. multilocularis and E. granulosus occur in this area. Serological prevalence was far higher than disease prevalence in this age range. We found no gender-related differences of seroprevalence among the children, suggesting an equal chance of exposure to echinococcal egg-contaminated environments. The seroprevalence distribution was associated with changes in the ecology of wild hosts for E. multilocularis contamination, and with changes in socio-geographic features of the communities for E. granulosus contamination.
Conclusions  Serological data obtained for children in mass surveys of echinococcosis appear to be a comprehensive and useful tool to monitor changes of transmission dynamics in humans and provide 'warning signals' to decision makers for the instigation of specific control measures against the disease.     

Intestinal and systemic humoral immunological events in the susceptible Balb/C mouse strain after oral administration of Echinococcus multilocularis eggs

The aim of the study was to investigate the systemic and, for the first time, the intestinal humoral events in the susceptible Balb/C mouse strain after oral administration of Echinococcus multilocularis eggs. Thirty-one mice were divided into three groups; W-2 , W-8 and control group. Each mouse of the W-2 and W-8 groups was orally infected with 1,500 E. multilocularis eggs, two weeks and eight weeks before sacrifice respectively. Control group mice received phosphate buffer saline. Measurement of anti- E. multilocularis and non-specific IgG, IgA and IgM, and of a transudation marker, albumin, were performed in serum and intestinal washings by a time-resolved immunofluorometric assay. These results were complemented by microscopic examination of the intestinal mucosa. This infection model is well-suited to the study of mucosal immunity during alveolar echinococcosis. It showed a major specific intestinal response in the early stage of the disease whereas the systemic response predominated later in the disease. Histopathological studies and calculation of the relative coefficient of excretion of Ig also confirmed that the presence of the parasite, even during a short period, was responsible for a local immunological and inflammatory response and for a change in mucosal permeability. Mucosal immunity could thus play a role in tolerance induction against E. multilocularis that could be a prerequisite for the subsequent development of the larvae in the liver, and for the occurrence of the parasitic disease, alveolar echinococcosis .     

新疆新源县和四川石渠县啮齿动物及家畜棘球绦虫线粒体cox1基因遗传多态性分析

目的了解新疆新源县和四川石渠县棘球绦虫线粒体细胞色素。氧化酶亚基1 (cox1)基因的遗传多态性,探讨棘球绦虫在我国的传播动力和传播方向。方法 2014-2018年,在新疆新源县、四川石渠县捕捉啮齿类动物并采集其肝组织样品,收集家畜病变脏器。提取肝组织和病变脏器组织的DNA,PCR扩增棘球绦虫cox1基因片段,经分子克隆、测序后,在NCBI数据库中比对以确定所感染的虫种。使用Clustal X2和MEGA 7剪辑序列,使用DnaSP v5和Arlequin 3.5计算核苷酸多态性和中性检验,分析新源县和石渠县棘球绦虫的遗传多样性。以石渠棘球绦虫为外群,用MrBayes 3.2.4建立基于cox1基因的贝叶斯系统进化树,总结分析虫种的基因型。采用Network 5.0绘制棘球绦虫cox1基因的单倍型网络图,分析单倍型结构。结果在新疆新源县捕获普通田鼠122只,收集绵羊病变脏器5个;在四川石渠县捕获青海田鼠144只、经营田鼠44只和高原鼠兔135只,收集牦牛病变脏器6个。其中从5只绵羊、4头牦牛的病变脏器样品DNA扩增获得细粒棘球绦虫cox1基因片段40条(新源县26条,石渠县14条),从8只普通田鼠、14只青海田鼠、5只经营田鼠和2只高原鼠兔获得多房棘球绦虫线粒体cox1基因59条(新源县20条,石渠县39条),扩增产物长度均为875 bp。细粒棘球绦虫在两地的遗传分化程度(Fst=0.088 63)高于多房棘球绦虫(Fst=0.000 88),新源县细粒棘球绦虫遗传多样性(0.002 58±0.000 46)低于石渠县(0.005 88±0.000 58),而其多房棘球绦虫遗传多样性(0.002 28±0.000 46)高于石渠县(0.001 37±0.000 30)。贝叶斯系统进化树显示,两地的细粒棘球绦虫基因型为G1型,多房棘球绦虫为亚洲型。序列比对发现25个细粒棘球绦虫cox1基因单倍型(新源县15个,石渠县9个,共同单倍型1个)和29个多房棘球绦虫cox1基因单倍型(新源县13个,石渠县15个,共同单倍型1个),两种棘球绦虫的单倍型网络图均为环绕主单倍型(共同单倍型)的辐射状结构,新源县的细粒棘球绦虫序列中有9条为主单倍型(34.6%,9/26),而石渠县仅有1条(1/14),显示出新源县在细粒棘球绦虫单倍型结构中的核心位置;石渠县的多房棘球绦虫基因序列中有23条为主单倍型(58.9%,23/39),而新源县为7条(35.0%,7/20),表明石渠县在多房棘球绦虫的单倍型结构中更具有主导地位。结论新源县和石渠县的棘球绦虫线粒体cox1基因型一致,但遗传多态性存在一定差异,同等空间跨度上细粒棘球绦虫的遗传分化程度要高于多房棘球绦虫,这些差异为探讨棘球绦虫传播方向和动力提供了重要参考依据。     

Echinococcosis in Arizona and New Mexico. Survey of hospital records, 1969-1974.

In 1974, seven cases of human echinococcosis were diagnosed in Arizona and New Mexico. A retrospective survey of Arizona and New Mexico hospitals obtained data on ten additional cases reported for the 5-year period 1969 through 1973. Sixteen cases were diagnosed as Echinococcus granulosus infections and one as E. multilocularis infection. The latter infection was in an Eskimo from Alaska, where E. multilocularis is endemic. All of the 16 E. granulosus cases were probably acquired autochthonously; 14 were diagnosed in American Indians of the Navajo (8 cases), Zuni (4 cases), and Santo Domingo (2 cases) tribes; the remaining 2 cases were diagnosed in non-Indian women. This is the first published account of echinococcosis autochthonous to Arizona and New Mexico. Evidence suggests that the infection may have been introduced only relatively recently to the areas populated by the American Indians and that parasite transmission to humans is increasing.     

Epidemiology and Transmission of Kaposi’s Sarcoma-Associated Herpesvirus

This review summarizes the current knowledge pertaining to Kaposi sarcoma-associated herpesvirus (KSHV) epidemiology and transmission. Since the identification of KSHV twenty years ago, it is now known to be associated with Kaposi’s sarcoma (KS), primary effusion lymphoma, and multicentric Castleman’s disease. Many studies have been conducted to understand its epidemiology and pathogenesis and their results clearly show that the worldwide distribution of KSHV is uneven. Some geographical areas, such as sub-Saharan Africa, the Mediterranean region and the Xinjiang region of China, are endemic areas, but Western Europe and United States have a low prevalence in the general population. This makes it imperative to understand the risk factors associated with acquisition of infection. KSHV can be transmitted via sexual contact and non-sexual routes, such as transfusion of contaminated blood and tissues transplants, or via saliva contact. There is now a general consensus that salivary transmission is the main route of transmission, especially in children residing in endemic areas. Therefore, there is a need to better understand the sources of transmission to young children. Additionally, lack of animal models to study transmission, gold standard serological assay and the lack of emphasis on endemic KS research has hampered the efforts to further delineate KSHV transmission in order to design effective prevention strategies.     

两种致病人体棘球绦虫动物宿主感染及影响因素研究进展

棘球蚴病是由棘球绦虫幼虫感染所致的一种危害严重的人兽共患寄生虫病。棘球绦虫生活史可涉及多种动物宿主,如有蹄类动物、啮齿类动物等中间宿主和食肉类动物终末宿主。自然界动物宿主间细粒棘球绦虫及多房棘球绦虫生活史循环与人体棘球蚴病传播密切相关。本文综述了近年来国内外有关细粒棘球绦虫和多房棘球绦虫主要动物宿主分布及感染的影响因素研究进展,旨在为开展棘球蚴病精准防治提供参考。     

Echinococcosis

Echinococcosis is a near-cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). The two major species of medical and public health importance are Echinococcus granulosus and Echinococcus multilocularis, which cause cystic echinococcosis and alveolar echinococcosis, respectively. Both are serious and severe diseases, the latter especially so, with high fatality rates and poor prognosis if managed incorrectly. Several reports have shown that both diseases are of increasing public health concern and that both can be regarded as emerging or re-emerging diseases. In this review we discuss aspects of the biology, life cycle, aetiology, distribution, and transmission of the Echinococcus organisms, and the epidemiology, clinical features, treatment, and diagnosis of the diseases they cause. We also discuss the countermeasures available for the control and prevention of these diseases. E granulosus still has a wide geographical distribution, although effective control against cystic echinococcosis has been achieved in some regions. E multilocularis and alveolar echinococcosis are more problematic, since the primary transmission cycle is almost always sylvatic so that efficient and cost-effective methods for control are unavailable.     

新疆额敏县首次发现水(鼠平)感染多房棘球蚴

2001年5月在新疆塔城地区额敏县境内塔尔巴哈台山和齐吾尔喀什尔山区域的巴衣木扎地区在一只水Bing（Arvicola terrestris Linnaeus,1758)肝脏中发现有多房棘球蚴（Metacestode of Echinococcus multilocularis)自然感染，感染率为1．6％（1／61），为我国水Bing中发现多房棘球蚴寄生的首次记录。     

Past to present: echinococcosis in Turkey

Echinococcosis is a zoonotic infection caused by Echinococcus spp. and is one of the most important helminthic diseases worldwide. Two forms of echinococcosis occur in Turkey, i.e. Echinococcus granulosus and E. multilocularis. The life cycle of E. granulosus is predominantly in dogs and sheep, and most sheep farmers in Turkey keep a dog or two. Stray dogs are numerous and prevention or treatment of infection in these dogs is very difficult. Cystic echinococcosis (CE) occurs throughout Turkey whereas alveolar echinococcosis (AE) predominantly occurs in the eastern Anatolian region of the country. Both CE and AE are known to be endemic but few surveys have been performed. Most data on human CE and AE have been collected from hospital records. The first reference of echinococcosis, "Kyste hydatique multiloculaire", in Turkey dates as far back to 1872 by an Ottoman Physician, C.R. Katibian. The results of the first Turkish study on E. granulosus were published in 1928. According to Ministry of Health records, 21303 patients had operations to treat or confirm CE in the period 1987-1994 which corresponds to approximately 2663 patients per year. The estimated surgical case rate of CE is 0.87-6.6 per 100000 in Turkey. The prevalence of E. granulosus infection in dogs in Turkey is between 0.32 and 40% and varies widely with geographical location. The reported prevalence of CE in domestic animals in Turkey has ranged from 11.2 to 50.7% and has varied widely with geographical location. Although no detailed information has been published on AE in domestic and wild animals in Turkey, the main definitive and intermediate hosts of E. multilocularis are assumed to be rodents and red foxes, respectively. However, there has been only a single published report of E. multilocularis in a wild animal (fox) in the northwest in 1965 by Merdivenci. The first human case of AE in Turkey was reported by Mutlu in 1939, and total cumulative reported case number is 202 between 1980 and 1998.     

Spontaneous death of Echinococcus multilocularis: cases diagnosed serologically (by Em2 ELISA) and clinical significance

Nine cases of asymptomatic alveolar hydatid disease (AHD) of the liver were diagnosed in 1985 among Eskimos from the endemic region of western Alaska. The patients were identified by screening with the enzyme-linked immunosorbent assay, using purified Echinococcus multilocularis antigen (Em2 ELISA). Five patients, and one diagnosed earlier (1979), were found to have lesions in which the larval E. multilocularis had died spontaneously at an early stage of infection. Viability was assessed histologically; by the avidin-biotin immunohistochemical method; and in vivo through intraperitoneal inoculation of membranes of the larval cestode into red-backed voles, Clethrionomys rutilus. The results were in agreement with the clinical impression, based on findings by computerized tomography and ultrasound scanning, and on the macroscopic appearance of the lesions, that the cestode was dead. Spontaneous death of E. multilocularis in humans has not been previously reported. The findings show that the Em2 ELISA may be positive in patients having lesions of AHD in which the etiologic agent is no longer viable.     

青藏高原东部地区发现的新种: 石渠棘球绦虫的生物学特征

青藏高原东部是细粒棘球绦虫和多房棘球绦虫的混合流行区,诸多的家畜和野生动物参与了棘球绦虫的传播。近年来,一种未知的棘球绦虫先后从高原鼠兔（Ochotona curzoniae）和藏狐（Vulpes ferrilata）中被分离出来。由于其特有的形态学、分子遗传学、寄生宿主和地理分布特征,而被作为新种 ——— 石渠棘球绦虫（Echinococcus shiquicus,Xiao et al,2005）进行了系统研究。本文对该虫种的生物遗传学和流行病学特征进行了讨论,并提出了理论上的假设来解释一些仍不十分清楚的现象。     

Geographic information system-aided analysis of factors associated with the spatial distribution of Echinococcus multilocularis infections of foxes.

To investigate the influence of environmental factors on the spatial epidemiology of infections with Echinococcus multilocularis, foxes were sampled in a focal endemic region in the Northwest of Brandenburg, Germany, and examined for infection by the parasite. The locations where foxes were obtained were recorded in a geographic information system database. Positions of infected and uninfected foxes were analyzed on the background of geographic vector data of water, settlements, streets, forests, crop, and pasture. Fox positions were allocated to different land-use classes by use of a Landsat Thematic Mapper (TM) satellite image. Infected foxes were more frequently shot near water, in areas of high soil humidity, and on pastures, suggesting that dryness may limit the tenacity of E. multilocularis oncospheres. Thus open landscapes with humid soil seem to be favorable for the life cycle of the parasite. In contrast, infected foxes were significantly underrepresented in forest areas.     

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.     

四川省藏族牧区家犬棘球绦虫病流行病学调查研究(英文）

目的 对四川省甘孜县达通玛藏族牧区家犬感染细粒棘球棘球绦虫和多房棘球棘球绦虫进行流行病学调查和评价感染风险因素。 方法 分别对甘孜县达通玛藏族牧区查龙、卡龙、大德和查扎等4乡的犬主进行问卷调查,了解家犬感染棘球绦虫的相关因素。剖检流浪犬,检测棘球绦虫感染率,并用此结果评价粪抗原?鄄ELISA方法。用该方法检测家犬感染棘球绦虫的阳性率,评价犬驱虫效果。用χ2 检验和方差分析对结果进行统计。 结果 2000年流浪犬棘球绦虫感染率为60.9%（14/23）,其中细粒棘球绦虫感染率为26.1%（6/23）,多房棘球绦虫感染率为34.8%（8/23）。粪抗原?鄄ELISA特异性为80.0%,敏感性为92.3%。家犬粪抗原?鄄ELISA阳性率平均为50%（290/580）。从2003年起,经每半年1次吡喹酮犬驱虫（5 mg/kg）,2005年同一犬群粪抗原阳性率降为17.0%（99/580）。犬感染风险因素调查发现敞放犬粪抗原阳性率[40.4%（65/161）]明显高于半栓养犬[白天拴养夜晚放养的犬32.3%（109/337）;夜晚拴养白天放养的犬29.2%（21/72)]及一直栓养的犬[20%（2/10）] （P＜0.01）;主人缺乏防治相关知识的犬[38.1%（121/318）]和不进行驱虫的犬[47.7%（92/193）],阳性率明显高于主人具有相关知识[28.6%（75/262）]和驱虫犬[20.4%（79/387）] （P＜0.05 和P＜0.01）。粪抗原?鄄ELISA阳性率与犬的年龄、性别和饲养家畜的种类无关。 结论 四川省甘孜县达通玛藏族牧区是家犬两种棘球绦虫病流行区。粪抗原?鄄ELISA法可用于检测犬棘球蚴病。犬敞放和不对犬驱虫,以及牧民缺乏相关知识是造成家犬棘球蚴病传播、流行的重要原因。