长膜壳绦虫卵和短膜壳绦虫卵透射电镜观察

用透射电镜观察两种膜壳绦虫卵,长膜壳绦虫卵自外向内观察到的结构是卵壳外层、卵壳内层、透明层、膜状结构层、胚膜外层、胚膜内层、六钩蚴膜。最内为六钩蚴,六钩蚴主要分为六蚴区和腺样组织区。短膜壳绦虫卵基本结构与上述相似,自外向内包括菲薄的卵壳、膜状结构层、透明层、胚膜,最内为六钩蚴,亦分六钩区和腺样组织区,但六钩蚴的小钩两者结构不一致。     

寄生人体缩小膜壳绦虫成虫及虫卵的扫描电镜观察

服用槟榔（１００ｇ）煎剂和硫酸镁（３０ｇ），从１例感染者肠道驱出缩小膜壳绦虫４１条。扫描电镜观察，成虫和虫卵的形态与鼠内虫体基本相似。但微毛仅见于头节和成节，乳突仅于幼节见到。顶突呈菜花样隆起，无微毛和乳突。吸盘附近发现２个长约６μｍ的三角形孔穴。结果提示，人类和鼠类的缩小膜壳绦虫之间可能存在不同的生理型。     

Immunological and histopathological reactions of the rat against the tapeworm Hymenolepis diminuta and the effects of anti-thymocyte serum

Summary Anti-thymocyte-serum (ATS) treated Wistar rats infected with 100 cysticercoids of the rat intestinal cestode Hymenolepis diminuta showed a delayed destrobilation and expulsion of the worms compared with saline-treated infected rats. This result strengthens previous evidence of an immunological nature of the destrobilation and expulsion in lumen-dwelling cestodes—even in their most susceptible hosts. The migration of the worms in the small intestine during the first 20 days of a primary 100-worm infection is described and the anterior migration of the destrobilated worms to the first 10% of the pylorus is emphasized and compared with similar migrations of the nematode Nippostrongylus brasiliensis in the rat. No serum antibodies were detected using passive cutaneous anaphylaxis and the indirect immunofluorescence test, although the thymus-independent areas of the mesenteric lymph nodes showed an increase in pyroninophilic cells. In the small intestine, no response to the tapeworm infection could be detected in pyroninophilic cells and globule leucocytes, but mast cell and eosinophilic cell numbers were increased in the saline-treated infected rats. Although the host responses to H. diminuta are shown to be thymus-dependent, the possibility of thymus-independent activity in the host reactions cannot be ruled out.     

Discovery of Novel Alphacoronaviruses in European Rodents and Shrews

Eight hundred and thirteen European rodents and shrews encompassing seven different species were screened for alphacoronaviruses using PCR detection. Novel alphacoronaviruses were detected in the species Rattus norvegicus, Microtus agrestis, Sorex araneus and Myodes glareolus. These, together with the recently described Lucheng virus found in China, form a distinct rodent/shrew-specific clade within the coronavirus phylogeny. Across a highly conserved region of the viral polymerase gene, the new members of this clade were up to 22% dissimilar at the nucleotide level to the previously described Lucheng virus. As such they might represent distinct species of alphacoronaviruses. These data greatly extend our knowledge of wildlife reservoirs of alphacoronaviruses.     

Analysis of antibody responses to Hymenolepis nana infection in mice by the enzyme-linked immunosorbent assay and immunoprecipitation

Serum antibody responses in two strains of mice infected with embryonated eggs of Hymenolepis nana were analysed by the enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation (IP) using sodium deoxycholate (DOC)-solubilized antigens prepared from embryonated eggs (eggs), mouse-derived cysticercoids (cysts) and adult tapeworms with immature segments only (adults). Highly susceptible dd mice, which harbour mature tapeworms for a long period (greater than 70 days), produced high levels of antibodies to all three different stages of H. nana. BALB/c mice, almost all of which expel adult tapeworms by 30 days after infection, produced high levels of antibody against egg antigens only. The high antibody titres to cyst and adult antigens in dd mice did not lead to expulsion of the worms. However, worms are rejected early in BALB/c mice when there is little or no detectable serum antibody. The antibody responses to eggs seen in BALB/c mice which had long since shed their adult worms were probably due to ingestion of eggs from faeces of other infected mice. Antibodies to eggs were not detected in BALB/c mice which were initially inoculated with eggs (day 0) and then treated with praziquantel on day 6 after the tissue phase of infection only. The different antibody responses to egg antigens and the other two antigens (cyst and adult) in BALB/c mice suggest a difference in antigen specificity between eggs and both cysts and adults. A major antigen component with Mr 32,000 appears to be specific to the egg (or oncosphere) stage of H. nana. Antibody to this major component of eggs was absorbed only with intact eggs, but not with intact cysts nor adults with immature segments only, so that the antigen appears to be on the surface of the oncosphere.     

Prevalence of Orthohantavirus-Reactive Antibodies in Humans and Peri-Domestic Rodents in Northern Ethiopia

In 2012, Tigray orthohantavirus was discovered in Ethiopia, but its seasonal infection in small mammals, and whether it poses a risk to humans was unknown. The occurrence of small mammals, rodents and shrews, in human inhabitations in northern Ethiopia is affected by season and presence of stone bunds. We sampled small mammals in two seasons from low- and high-density stone bund fields adjacent to houses and community-protected semi-natural habitats in Atsbi and Hagere Selam, where Tigray orthohantavirus was first discovered. We collected blood samples from both small mammals and residents using filter paper. The presence of orthohantavirus-reactive antibodies in blood was then analyzed using immunofluorescence assay (human samples) and enzyme linked immunosorbent assays (small mammal samples) with Puumala orthohantavirus as antigen. Viral RNA was detected by RT-PCR using small mammal blood samples. Total orthohantavirus prevalence (antibodies or virus RNA) in the small mammals was 3.37%. The positive animals were three Stenocephalemys albipes rats (prevalence in this species = 13.04%). The low prevalence made it impossible to determine whether season and stone bunds were associated with orthohantavirus prevalence in the small mammals. In humans, we report the first detection of orthohantavirus-reactive IgG antibodies in Ethiopia (seroprevalence = 5.26%). S. albipes lives in close proximity to humans, likely increasing the risk of zoonotic transmission.     

肠道寄生虫感染干预策略和措施的评价

目的　评价浙江省肠道寄生虫感染干预策略及各种干预措施的效果。　方法　以县为单位,随机抽样10个县30个村为调查点,调查各地的干预措施和干预前后寄生虫感染率,比较干预前后各相关干预措施对降低寄生虫总感染率的保护率(PR)、效果指数(IE)。　结果　实施干预后,除蛲虫感染率上升以外,其它各主要寄生虫感染率及寄生虫总感染率都有明显下降,总感染率由10年前的77.0%降至10年后的22.84%,总保护率为70.34%,总效果指数为3.37。各县分别统计,保护率均在45%以上,效果指数为1.85～14.47。开展改厕、发展经济、健康教育的干预效果依次排在前三位。　结论　结合社会经济发展,采取健康教育、环境改造和集体驱虫等措施,能有效控制寄生虫再感染。     

Immunoglobulin E and mast cell responses are related to worm biomass but not expulsion of Hymenolepis diminuta during low dose infection in rats

It is well known that the destrobilation and later expulsion are characteristics of multiple Hymenolepis diminuta infections in rats. This process is suggested to be mediated by a variety of host cellular responses. It has also been suggested that immunoglobulin (Ig) E may have a beneficial role for some cestodes including H. diminuta. We examined the intestinal mast cell and serum IgE responses to a 10-H. diminuta infection in three different rat strains. Tapeworm infection induced no increased mast cell and IgE responses in F344 rats in which neither worm biomass nor worm burden decreased during 6 weeks of observation. The number of mast cells and amounts of serum rat mast cell protease (RMCP) II and IgE markedly increased from 3 weeks postinfection (p.i.) in BN rats. The worm biomass in BN rats was significantly lower than that in F344 rats, but worm burden was not different from that in F344 rats at 3 or 6 weeks p.i. In DA rats, the number of mast cells and levels of serum RMCP II and IgE increased at 6 weeks but not at 3 weeks p.i. Although numbers of mast cells and serum RMCP II and IgE levels were lower in DA rats than in BN rats, smaller and fewer worms were recovered in DA rats than in F344 and BN rats at from 3 and 6 weeks p.i. Worms were recovered from all of F344 and BN rats, while only 40% of DA rats harboured worms at 6 weeks p.i. These results suggested that the worm biomass was related to mast cell and IgE responses, but these responses were not required for worm expulsion during low dose H. diminuta infection in rats.     

微小膜壳绦虫感染对ICR小鼠小肠LY6A(Sca-1)及IFN-γ、STAT1表达的影响

目的 探讨微小膜壳绦虫感染ICR小鼠小肠组织中LY6A及IFN-γ、STAT1的表达情况。方法 采集微小膜壳绦虫成虫标本并收集虫卵制作悬液。将ICR小鼠随机分为对照组和实验组,实验组以定量1 000个/只虫卵灌胃感染,于感染后第2 d和第8 d按照编号处死小鼠获取小肠组织。采用HE染色进行小肠组织病理学观察,RT-PCR技术检测LY6A、IFN-γ和STAT1的mRNA相对表达量,免疫组织化学技术检测小肠中LY6A蛋白阳性细胞的表达,并用PRM技术对LY6A蛋白和STAT1蛋白进行相对丰度定量。结果 HE染色结果显示感染后第8 d在肠腔内发现成虫节片,并且虫体寄生处出现急性炎症反应。RT-PCR检测显示感染第2 d实验组LY6A(t=12.57,P<0.001)和STAT1(t=12.13,P<0.001)的mRNA相对表达量低于对照组,而IFN-γ的mRNA相对表达量高于对照组(t=7.78,P<0.01);感染后第8 d实验组LY6A(t=10.01,P<0.001)和STAT1(t=11.19,P<0.001)的mRNA相对表达量高于对照组;而IFN-γ的mRNA相对表达量低于对照组(t=26.47,P<0.001)。免疫组化结果显示感染后第2 d实验组LY6A阳性细胞百分比高于对照组(t=4.26,P<0.01),感染后第8 d实验组LY6A蛋白阳性细胞百分比高于对照组(t=8.18,P<0.001)。PRM检测结果显示感染后第2 d实验组LY6A蛋白相对表达量低于对照组(t=6.55,P<0.05),实验组STAT1蛋白与对照组相比无统计学差异,感染后第8 d实验组LY6A蛋白(t=4.95,P<0.05)和STAT1(t=2.91,P<0.05)蛋白的相对表达量均高于对照组。结论 微小膜壳绦虫感染ICR小鼠小肠后LY6A(Sca-1)的mRNA水平和蛋白水平在幼虫侵入早期呈低表达,成虫期呈高表达;IFN-γ对LY6A的表达不起主导作用,而STAT1可能对LY6A(Sca-1)的表达起诱导作用。     

Immunogenetic Factors Affecting Susceptibility of Humans and Rodents to Hantaviruses and the Clinical Course of Hantaviral Disease in Humans

We reviewed the associations of immunity-related genes with susceptibility of humans and rodents to hantaviruses, and with severity of hantaviral diseases in humans. Several class I and class II HLA haplotypes were linked with severe or benign hantavirus infections, and these haplotypes varied among localities and hantaviruses. The polymorphism of other immunity-related genes including the C4A gene and a high-producing genotype of TNF gene associated with severe PUUV infection. Additional genes that may contribute to disease or to PUUV infection severity include non-carriage of the interleukin-1 receptor antagonist (IL-1RA) allele 2 and IL-1β (-511) allele 2, polymorphisms of plasminogen activator inhibitor (PAI-1) and platelet GP1a. In addition, immunogenetic studies have been conducted to identify mechanisms that could be linked with the persistence/clearance of hantaviruses in reservoirs. Persistence was associated during experimental infections with an upregulation of anti-inflammatory responses. Using natural rodent population samples, polymorphisms and/or expression levels of several genes have been analyzed. These genes were selected based on the literature of rodent or human/hantavirus interactions (some Mhc class II genes, Tnf promoter, and genes encoding the proteins TLR4, TLR7, Mx2 and β3 integrin). The comparison of genetic differentiation estimated between bank vole populations sampled over Europe, at neutral and candidate genes, has allowed to evidence signatures of selection for Tnf, Mx2 and the Drb Mhc class II genes. Altogether, these results corroborated the hypothesis of an evolution of tolerance strategies in rodents. We finally discuss the importance of these results from the medical and epidemiological perspectives.     

Experimental and Natural Infections of Tick-Borne Encephalitis Virus in Dogs

Dogs are frequently infected with the tick-borne encephalitis virus (TBEV). However, to date, only a few clinically manifest cases of tick-borne encephalitis (TBE) have been reported in dogs. In this study, three-month-old beagle dogs were infected with TBEV through a subcutaneous injection. Body temperature, clinical signs, blood haematology, blood biochemistry, and immune responses were monitored for up to 28 days postinfection (p.i.). No changes in body temperature or clinical signs were observed in the infected dogs. Most haematology and blood biochemistry parameters were unchanged after the infection, except for a slight reduction in blood lymphocyte counts, but they were within the physiological range. Low-titre viraemia was detected in 2/4 infected dogs between days 1 and 3 p.i. All infected dogs developed a robust immune response, in terms of neutralising antibodies. Thus, TBEV infections lead to effective seroconversion in dogs. Next, to assess TBEV exposure in dogs in the TBEV-endemic region of the Czech Republic, we conducted a serosurvey. Virus neutralisation tests revealed TBEV-specific antibodies in 17 of 130 (13.07%) healthy dogs, which confirmed a high, but clinically inappreciable TBEV exposure rate in the endemic area. The seropositivity rate was similar (12.7%; 41 positives out of 323) in a subgroup of dogs with various clinical disorders, and it was 13.4% (23 out of 171) in a subgroup of dogs with signs of acute neurological disease. Two dogs with fatal acute meningoencephalitis showed positive results for TBEV-specific IgM and IgG antibodies. These data extended our understanding of the clinical presentation of TBEV infections.     

Lymphatic Filariasis: Perspectives on Lymphatic Remodeling and Contractile Dysfunction in Filarial Disease Pathogenesis

Lymphatic filariasis, one of the most debilitating diseases associated with the lymphatic system, affects over a hundred million people worldwide and manifests itself in a variety of severe clinical pathologies. The filarial parasites specifically target the lymphatics and impair lymph flow, which is critical for the normal functions of the lymphatic system in maintenance of body fluid balance and physiological interstitial fluid transport. The resultant contractile dysfunction of the lymphatics causes fluid accumulation and lymphedema, one of the major pathologies associated with filarial infection. In this review, we take a closer look at the contractile mechanisms of the lymphatics, its altered functions, and remodeling during an inflammatory state and how it relates to the severe pathogenesis underlying a filarial infection. We further elaborate on the complex host–parasite interactions, and molecular mechanisms contributing to the disease pathogenesis. The overall emphasis is on elucidating some of the emerging concepts and new directions that aim to harness the process of lymphangiogenesis or enhance contractility in a dysfunctional lymphatics, thereby restoring the fluid imbalance and mitigating the pathological conditions of lymphatic filariasis.     

外膜蛋白检测与质粒分析对比研究在医院内不动杆菌感染中的应用

为追溯不动杆菌医院感染的感染源和感染途径，作者借助临床分离的与医院感染相关的４８株不动杆菌，同时采用质粒及其限制性内切酶图谱和外膜蛋白图谱分型。４８株菌中，３３株含有质粒，构成的质粒图谱、质粒内切酶图谱及外膜蛋白图谱均为１８个型；而不含质粒的１５株菌可进一步用外膜蛋白图谱分为９个型。结果表明：质粒分析、尤其是结合外膜蛋白图谱分型可较好地用于不动杆菌医院感染的流行病学调查。     

Genetic Diversity of Puumala orthohantavirus in Rodents and Human Patients in Austria, 2012–2019

Puumala orthohantavirus (PUUV) has a wide distribution throughout Europe. Distinctive temporal patterns of spillover into the human population are related to population dynamics of the reservoir host, the bank vole (Clethrionomys glareolus). As the rodent host is tied to specific habitats with small individual ranges, PUUV genetic diversity is also highly correlated with geographic distance. Using sequenced portions of viral S and M segments, we determined whether geographic clusters were supported. Human cases of PUUV infections are concentrated in southeastern Austria. We detected four distinct genotypes: two genotypes of the Alpe-Adria (ALAD) lineage typically associated with southeast Europe, and two sublineages of the Central Europe (CE) lineage. One cluster of CE genotypes represents a phylogenetically distinct sublineage compared to previously reported CE clades, and extends the boundary of the CE lineage further south than previously reported.     

银川河东机场鼠类密度、季节消长状况分析

目的了解宁夏银川河东机场鼠类密度、季节消长情况及种群分布,为防控鼠害、预防鼠传播疾病提供科学依据。方法采用夹日法、昼夜弓形夹法和5m夹线法在机场不同地点进行调查。结果①共布放有效鼠夹7463夹次,捕获鼠类32只,经鉴定隶属于啮齿目-鼠科-家鼠属-褐家鼠占21.9%;小家属-小家鼠占31.2%;松鼠科-黄鼠属-达乌尔黄鼠阿拉善亚种（简称阿拉善黄鼠）占34.4%;仓鼠科-沙鼠属-子午沙鼠占12.5%,黄鼠为优势种。②生活区（家栖鼠）鼠类平均密度为0.28只/100间,候机楼未捕获到鼠,停机坪（野栖鼠）鼠类平均密度为0.22只/hm2。③鼠类季节消长家栖鼠以4、10月份为高峰期,野栖鼠以6月份为高峰期,在1、2、9、11月份鼠密度为零。结论银川河东机场鼠密度较低,鼠种构成相对简单,达到基本无鼠害机场,今后还必须持之以恒,坚持科学灭鼠,严防疫情输入,巩固灭鼠达标成果。     

新疆北部大沙鼠的生存环境以及鼠间的利什曼原虫和媒介的调查

在新疆天山北部的荒漠内，很多大沙鼠Ｒｈｏｍｂｏｍｙｓ ｏｐｉｍｕｓ的耳皮下组织内有利什曼原虫的感染。有的地方，鼠的感染率可达１００％（ＮＮＮ基培养法），已鉴定的原虫有都兰利什曼Ｌｅｉｓｈｍａ－ｎｉａ ｔｕｒａｎｉｃａ和沙鼠利什曼Ｌ．ｇｅｒｂｉｌｌｉ两种。大沙鼠洞是多种白蛉的栖息和吸血的场所，洞内的优势蛉种为蒙古白蛉Ｐｈｌｅｂｏｔｏｍｕｓ ｍｏｎｇｏｌｅｎｓｉｓ和安氏白蛉Ｐｈ．ａｎｄｒｅｊｅｕｉ。调     

Serological,Molecular and Culture-Based Diagnosis of Lentiviral Infections in Small Ruminants

Small ruminant lentiviruses (SRLVs) infections lead to chronic diseases and remarkable economic losses undermining health and welfare of animals and the sustainability of farms. Early and definite diagnosis of SRLVs infections is the cornerstone for any control and eradication efforts; however, a “gold standard” test and/or diagnostic protocols with extensive applicability have yet to be developed. The main challenges preventing the development of a universally accepted diagnostic tool with sufficient sensitivity, specificity, and accuracy to be integrated in SRLVs control programs are the genetic variability of SRLVs associated with mutations, recombination, and cross-species transmission and the peculiarities of small ruminants’ humoral immune response regarding late seroconversion, as well as intermittent and epitope-specific antibody production. The objectives of this review paper were to summarize the available serological and molecular assays for the diagnosis of SRLVs, to highlight their diagnostic performance emphasizing on advantages and drawbacks of their application, and to discuss current and future perspectives, challenges, limitations and impacts regarding the development of reliable and efficient tools for the diagnosis of SRLVs infections.     

安徽省人体肠道蠕虫感染现状分析

目的掌握安徽省人体重要寄生虫病流行现状。方法按照全国统一方案，以分层整群随机抽样法调查安徽省10个抽样县(市)，29个土源性线虫调查点，每个点检查500人。采用改良加藤厚涂片法检查肠道蠕虫卵；试管滤纸培养法鉴定钩虫虫种及其它线虫幼虫；透明胶纸肛拭法检查全部12岁以下儿童蛲虫卵。结果．共调查14874人。检出肠道蠕虫13种。总感染率为21．43％，(其中男性19．63％，女性23．37％)，蛔虫、钩虫和鞭虫占全部感染者的91．28％，其中蛔虫、鞭虫和钩虫感染率分别为9．77％、3．14％和9．65％，华支睾吸虫为0．67％(100／14874)；蛲虫阳性率为5．39％(163／3022)；蛔虫和鞭虫感染沿江平原最高，钩虫和华支睾吸虫感染淮北平原最高。结论与我省第一次寄生虫病分布调查相比，发现虫种减少，总感染率及各虫种感染率均大幅度下降。老年龄组的感染率相对较高(尤其是女性)，老年人群在过去的防治中未得到应有的重视。     

Spatial and Temporal Dynamics and Molecular Evolution of Tula orthohantavirus in German Vole Populations

Tula orthohantavirus (TULV) is a rodent-borne hantavirus with broad geographical distribution in Europe. Its major reservoir is the common vole (Microtus arvalis), but TULV has also been detected in closely related vole species. Given the large distributional range and high amplitude population dynamics of common voles, this host–pathogen complex presents an ideal system to study the complex mechanisms of pathogen transmission in a wild rodent reservoir. We investigated the dynamics of TULV prevalence and the subsequent potential effects on the molecular evolution of TULV in common voles of the Central evolutionary lineage. Rodents were trapped for three years in four regions of Germany and samples were analyzed for the presence of TULV-reactive antibodies and TULV RNA with subsequent sequence determination. The results show that individual (sex) and population-level factors (abundance) of hosts were significant predictors of local TULV dynamics. At the large geographic scale, different phylogenetic TULV clades and an overall isolation-by-distance pattern in virus sequences were detected, while at the small scale (<4 km) this depended on the study area. In combination with an overall delayed density dependence, our results highlight that frequent, localized bottleneck events for the common vole and TULV do occur and can be offset by local recolonization dynamics.