A Case of Alveolar Echinococcosis Occurring in the Hilar Bile Duct

Echinococcosis is a disease caused by the Echinococcus species that parasitizes in humans. Alveolar echinococcosis (AE) which is caused by Echinococcus multilocularis is harmful to humans. AE mainly occurs in the liver and can be transferred to retroperitoneal lymph nodes, lung, brain, bone, spleen and other organs through lymphatic and blood vessels. Cholangiocarcinoma can occur in the intrahepatic and extrahepatic bile ducts and is more common in the hilar. We reported a case of hilar bile duct alveolar echinococcosis which was originally misdiagnosed an cholangiocarcinoma.

Analysis of Lethality in Echinococcal Disease

The information on mortality from echinococcosis is important not only for a better understanding of the severity of the disease, but also for evaluating the effectiveness of public health interventions. The aim of this research was to study the causes of mortality from echinococcosis. We have collected and analyzed the materials of 1,470 patients in 10 age - groups in the Republic of Armenia (from 2000 to 2016). To find out the causes of mortality from echinococcosis, we have analyzed the medical histories and protocols of postmortem examinations of 19 deaths from echinococcosis and 17 deaths due to other indirect causes not associated with the parasite. The average annual death rate from echinococcosis is 0.007 per 10,000 population, and the mortality is 1.29 (per 100 patients). The highest mortality occurs in people aged 70–79. Mortality from echinococcosis is also recorded among the unoperated children. The rupture of the parasitic cyst and hepatic insufficiency are major among the direct causes of mortality. Sometimes the hydatid cysts unrecognized during the life were first diagnosed at autopsy. Insufficient qualification of doctors in the field of helminthology, as well as the latent course of the disease or manifestation of minor symptoms in echinococcosis over a long period often led to medical errors. Further decline in mortality can be achieved by early diagnosis, timely hospitalization and treatment before the development of severe complications worsening the prognosis and outcomes of surgical intervention.

A Rapid and Convenient Method for in Vivo Fluorescent Imaging of Protoscolices of Echinococcus multilocularis

Human and animal alveolar echinococcosis (AE) are important helminth infections endemic in wide areas of the Northern hemisphere. Monitoring Echinococcus multilocularis viability and spread using real-time fluorescent imaging in vivo provides a fast method to evaluate the load of parasite. Here, we generated a kind of fluorescent protoscolices in vivo imaging model and utilized this model to assess the activity against E. multilocularis protoscolices of metformin (Met). Results indicated that JC-1 tagged E. multilocularis can be reliably and confidently used to monitor protoscolices in vitro and in vivo. The availability of this transient in vivo fluorescent imaging of E. multilocularis protoscolices constitutes an important step toward the long term bio-imaging research of the AE-infected mouse models. In addition, this will be of great interest for further research on infection strategies and development of drugs and vaccines against E. multilocularis and other cestodes.

Serological and Molecular Characteristics of the First Korean Case of Echinococcus multilocularis

In December 2011, we reported an autochthonous case of Echinococcus multilocularis infection in a 42-year-old woman in Korea. The diagnosis was based on histopathological findings of the surgically resected liver cyst. In the present study, we evaluated the serological and molecular characteristics of this Korean E. multilocularis case. The patient's serum strongly reacted with affinity-purified native Em18 and recombinant Em18 antigens (specific for E. multilocularis) but negative for recombinant antigen B8/1 (reactive for Echinococcus granulosus). In immunoaffinity chromatography, the serum also strongly reacted with E. multilocularis and only weakly positive for E. granulosus. We determined the whole nucleotide sequence of cox1 (1,608 bp) using the paraffin-embedded cystic tissue which was compared with E. multilocularis isolates from China, Japan, Kazakhstan, Austria, France, and Slovakia. The Korean case showed 99.8-99.9% similarity with isolates from Asia (the highest similarity with an isolate from Sichuan, China), whereas the similarity with European isolates ranged from 99.5 to 99.6%.

Echinococcus multilocularis infection leads to increased expression of proliferation and anti-apoptosis factors in liver cells in BALB/c mice / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effects of Echinococcus multilocularis on host liver cell proliferation in vivo using a BALB/c mouse alveolar hydatid infection model.</p><p><b>METHODS</b>Sixty-five 8-10-week-old female BALB/c mice were randomly divided into an experimental group (n = 40) and a control group (n = 25) and administered an abdominal injection into the left liver lobe of E. multilocularis protoscolices in saline solution or saline solution alone, respectively. At post-injection day 2, 8, 30, 60, and 90, liver samples were collected for analysis of lesions and lesion-adjacent tissue by hematoxylin-eosin staining and differential expression of proliferating cell nuclear antigen (PCNA), cyclin D1, cyclin A, and cyclin B1 by immunohistochemical staining. The significance of intergroup differences was assessed by Student's t-test.</p><p><b>RESULTS</b>The control group showed normal liver histology at all time points. The experimental group developed E. multilocularis lesions that showed increased severity of pathological features, such as inflammatory cell invasion, steatosis and fibrous connective tissue hyperplasia, over time. At post-injection days 2 and 8, enlarged, binuclear and apocyte hepatocytes were observed close to the lesions. At post-injection days 30, 60, and 90, the number of hepatocytes expressing PCNA progressively increased in the experimental group, and the numbers were significantly higher than in the control group (7.01 +/- 1.89 vs. 1.03 +/- 0.52, 8.41 +/- 2.80 vs. 0.93 +/- 0.31, and 13.4 +/- 4.43 vs. 1.07 +/- 0.94; all P < 0.05). The same progressively increasing trend was seen in the number of hepatocytes expressing CyclinD1, but was only significantly different from controls at post-injection days 30 and 60 (6.73 +/- 2.52 vs. 0.48 +/- 0.43 and 8.22 +/- 3.09 vs. 0.55 +/- 0.34; both P < 0.05). In contrast, the number of hepatocytes expressing cyclin A was significantly increased at post-injection day 30 and then showed a decreasing trend at days 60 and 90, although the numbers of expressing cells remained significantly higher than control levels at all time points (7.75 +/- 3.05 vs. 0.69 +/- 0.36, 3.42 +/- 1.80 vs. 1.14 +/- 0.42, and 3.03 +/- 1.50 vs. 0.69 +/- 0.31; all P < 0.05). The number of hepatocytes expressing CyclinB1 in the experimental group was less robust than the other cyclins (with a general temporal trend of increase followed by decrease), but the differential expression was not significantly different from the control levels at any time point.</p><p><b>CONCLUSION</b>E. multilocularis infection may promote the expression of host factors related to proliferation and anti-apoptosis in liver. This pathogen-mediated modulation of host cell-survival mechanisms may provide a rationale explanation for the clinical observations of hepatomegaly and the unexpected survival of alveolar echinococcosis patients following major hepatic resection.</p>

A Case of Budd-Chiari Syndrome Associated with Alveolar Echinococcosis

Although alveolar echinococcosis (AE) can cause a serious disease with high mortality and morbidity similar to malign neoplasms. A 62-year-old woman admitted to a hospital located in Sivas, Turkey, with the complaints of fatigue and right upper abdominal pain. On contrast abdominal CT, a 54x70x45 mm sized cystic lesion was detected in the left lobe of the liver that was seen to extend to the posterior mediastinum and invade the diaphragm, esophagus, and pericardium. The cystic lesion was seen to be occluding the inferior vena cava and left hepatic vein at the level where the hepatic veins poured into the inferior vena cava. Bilateral pleural effusion was also detected. We discussed this secondary Budd-Chiari Syndrome (BCS) case, resulting from the AE occlusion of the left hepatic vein and inferior vena cava, in light of the information in literature.

Immune responses on allograft heart transplantation in inbred rats infected with Echinococcosis multilocularis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Alveolar echinococcosis (AE) is caused by the metacestode stage of Echinococcus multilocularis (E. multilocularis) and is a rare but life-threatening disease. This disease commonly is characterized by an infiltrative, tumor-like growth of the E. multilocularis metacestode in the liver of human. Liver transplantation is an effective therapy for end-stage of hepatic AE, but the characteristics of host immunity associated with E. multilocularis infection with organ transplantation are poorly defined. We hereby aimed to study the immunological status and allograft heart survival in inbred rats with E. multilocularis infection.</p><p><b>METHODS</b>Rat models of AE were established by injecting the E. multilocularis suspension made from E. multilocularis infected tissues into the abdomen of Lewis (LEW) rats. Three months later, in the experimental group, allograft heart transplantation was performed from Brown-Norway (BN) rats to the E. multilocularis infected LEW rats. In the control group, we transplanted hearts from BN rats to healthy LEW rats. The influence of the disturbed immune system in E. multilocularis infected rats on the heart transplantation was assessed, including observation of allograft heart survival time, histopathological examination of grafts and immunohistochemical examination of infiltrating cells (CD4(+) T cells, CD8(+) T cells and eosinophile granulocytes), measurement of interleukin (IL)-4 and interferon (IFN)-γ in the serum by enzyme-linked immunosorbent assay (ELISA) and analysis of CD4(+)CD25(+) regulatory T cells in peripheral blood by fluorescence activated cell sorting (FACS) flow cytometric analysis.</p><p><b>RESULTS</b>The survival time of recipients in the experimental group was prolonged compared with those in the control group. The numbers of graft infiltrating CD8(+) T cells were decreased whereas the graft infiltrating eosinophil granulocytes (CD15(+)) were increased in grafts in the experimental group (P < 0.05). Furthermore, the proportion of CD4(+)CD25(+) regulatory T cells in the peripheral blood was 10.8% on average in the experimental group, which was significantly higher than that in the control group (6.1%). In addition, the level of serum IL-4 in E. multilocularis infected rats was higher than that in the control group rats, whereas the level of serum IFN-γ in experimental group was lower than that in the control group when graft rejection occurred (P < 0.05).</p><p><b>CONCLUSIONS</b>This study suggests that E. multilocularis infection could prolong the allograft survival time through the polarization of Th1/Th2-type cells and induction of CD4(+)CD25(+) regulatory T cells. This strategy may provide a new idea for establishing transplantation tolerance.</p>

Suppression of acute rejective response following orthotopic liver transplantation in experimental rats infected with Echinococcus multilocularis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Hepatic alveolar echinococcosis (AE) is a parasitic disease in humans and caused by the Echinococcus multilocularis (Em). Orthotopic liver transplantation (OLT) may be the only effective treatment for end-stage hepatic AE. However, in some AE patients, extrahepatic Em can not be completely eliminated after OLT. We aimed to study whether the immunological changes caused by Em evasion may influence the rejective response.</p><p><b>METHODS</b>Rat modles of AE were established by injecting the Em suspension into abdomen of Brown Norway (BN) rats. Three months later, in the experimental group, the liver was transplanted from Lewis (LEW) rats to Em-infected BN rats. In the control group, transplantation was from LEW rats to healthy BN rats. Liver tissue and peripheral blood (PB) samples were collected on days 1, 3, 5, and 7 after OLT. Liver tissue was analyzed after hematoxylin and eosin (H&E) staining; numbers of CD4, CD8, and CD28 on peripheral blood cells were detected by flow cytometry; and expression of the chemokine fractalkine (Fkn) was detected by reverse transcription PCR (RT-PCR). Interleukin-10 (IL-10) was measured in the serum by enzyme-linked immunosorbent assay (ELISA). In every group, eight BN rats were retained for observing survival time.</p><p><b>RESULTS</b>The survival times of recipients in the experimental group were prolonged compared with those in the control group. The rejective response occurred later and was milder in the experimental group. percentage of CD4, CD8, CD28 T-cells and Fkn mRNA expression were lower in the experimental group. While the serum IL-10 levels were higher in the experimental group than those in the control group.</p><p><b>CONCLUSIONS</b>Acute rejective response after OLT was attenuated in the rats with Em infection, and the recipients` survival time was prolonged. Em may play a role in this process by elevating IL-10 secretion, decreasing the effector T cells, inhibiting the expression of Fkn, which lead to reduce the inflammatory cells infiltration into the liver.</p>

Distribution of the intermediate hosts of Echinococcus multilocularis in Shiqu County, Sichuan, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The rodentia and lagomorpha animals are the intermediate hosts of Echinococcus multilocularis, their distribution and infection of this parasite may facilitate the infection of definitive hosts such as dogs. The aim of this study was to determine the distribution of the intermediate hosts of Echinococcus multilocularis in Shiqu County, Sichuan, China.</p><p><b>METHODS</b>A systematic sampling method was used to investigate the density of burrows of rodents and lagomorphs at 97 pasture sites in winter and summer pastureland and remote sensing (RS) technology was used to correlate their densities to the distribution of these animals in different landscape types.</p><p><b>RESULTS</b>Based on the densities of Ochotona curzoniae, Microtus fuscus (dependent variable) and their burrow densities (independent variable) in survey points, regression equations were fitted respectively (Ochotona curzoniae, P < 0.0001, R(2) = 0.8705; Microtus fuscus, P < 0.0001, R(2) = 0.9736). Their burrow density in summer pastureland was higher than in winter pastureland (F = 36.65, P < 0.0001). The burrow densities of Ochotona curzoniae and Microtus fuscus in bareland and half-bareland are higher than in grassland (F = 7.73, P < 0.001).</p><p><b>CONCLUSIONS</b>The regression relationship between the densities of Ochotona curzoniae and Microtus fuscus and their burrow densities indicate that the burrow densities could reflect the animal densities and that the burrow density was greater in summer pastureland than in winter pastureland. The main distribution areas of the intermediate hosts were in bareland and half-bareland.</p>

Grass height and transmission ecology of Echinococcus multilocularis in Tibetan communities, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Alveolar echinococcosis is a major zoonosis of public health significance in western China. Overgrazing was recently assumed as a potential risk factor for transmission of alveolar echinococcosis. The research was designed to further test the overgrazing hypothesis by investigating how overgrazing influenced the burrow density of intermediate host small mammals and how the burrow density of small mammals was associated with dog Echinococcus multilocularis infection.</p><p><b>METHODS</b>The study sites were chosen by previous studies which found areas where the alveolar echinococcosis was prevalent. The data, including grass height, burrow density of intermediate host small mammals, dog and fox fecal samples as well as Global Positioning System (GPS) position, were collected from field investigations in Shiqu County, Sichuan Province, China. The fecal samples were analyzed using copro-PCR. The worms, teeth, bones and hairs in the fecal samples were visually examined. Single factor and multifactor analyses tools including chi square and generalized linear models were applied to these data.</p><p><b>RESULTS</b>By using grass height as a proxy of grazing pressure in the homogenous pasture, this study found that taller grass in the pasture led to lower small mammals' burrow density (chi(2) = 4.670, P = 0.031, coefficient = -1.570). The Echinococcus multilocularis worm burden in dogs was statistically significantly related to the maximum density of the intermediate host Ochotona spp. (chi(2) = 5.250, P = 0.022, coefficient = 0.028). The prevalence in owned dogs was positively correlated to the number of stray dogs seen within a 200 meter radius (Wald chi(2) = 8.375, P = 0.004, odds ratio = 1.198).</p><p><b>CONCLUSIONS</b>Our findings support the hypothesis that overgrazing promotes transmission of alveolar echinococcosis and confirm the role of stray dogs in the transmission of alveolar echinococcosis.</p>

Prevalence of Echinococcus spp. infection using coproantigen ELISA among canids of Moghan plain, Iran

Echinococcosis is one of the most important helminthic zoonotic diseases in Iran. Intestinal Scraping Technique [IST], the traditional method for diagnosis of the infection in definitive hosts, has many disadvantages including low susceptibility and being expensive, hazardous and laborious. Detection of coproantigens in fecal samples by enzyme-linked immunosorbent assay [CA-ELISA] is known as a useful tool for intravital mass-screening of definitive host populations. This study was performed to determine the prevalence of Echinococcus spp. infection among canids in Moghan plain, the only area in Iran known to be endemic for E. multilocularis. One hundred thirty eight fecal samples were collected from red foxes and domestic dogs in three counties of Moghan plain namely Pars Abad, Bileh Savar and Germi. The samples were examined using an ELISA, designed for the detection of Echinococcus-specific coproantigen and the formalin-ether concentration method as well. Totally, out of 138 fecal samples, 27 [21.6%] turned positive for Echinococcus. Coproantigen was detected in 16.7% and 27.1% of red foxes and domestic dogs, respectively. Formalin-ether concentration method revealed that 43 [31.2%] of samples harbored at least one parasitic helminth, but Taenia eggs were detected only in 3 fecal samples. Since coproantigen presence reflects current intestinal infection with adult worms, CA-ELISA can be regarded as one of the most useful immunological tools for diagnosis of Echinococcus infection. Besides, the high susceptibility, low cost and rapidity

Echinococcosis / hydatidosis in Iran

Cystic echinococcosis caused by Echinococcus spp. is considered endemic in Iran. To clarify the present status of hydatidosis in Iran the present review article is presented. Authentic databases and search engines from 1996 onwards were utilized to enquire the situation of the disease in Iran. Human hydatidosis is responsible for approximately 1% of admission to surgical wards and the rate of human infection is 0.6-1.2/100000. The usual order of involvement, i.e. liver, lung, and other organs, respectively is documented here as well. Risk factors include contact with dog, eating vegetable, geophagy and contact with sheep. Dogs play a critical role in transition the hydatidosis. The rate of infection with E. granulosus in stray dogs shows a prevalence of 5% to 49% in different parts of Iran. Followed by sheep with 88% fertilized cysts, camel with 70%, and cattle with 19% have been considered as the most important and the weakest intermediate host of E. granulosus, respectively. Molecular analyses clearly indicate that the camel/dog strain [G6 genotype] of E. granulosus as well as the cosmopolitan, common sheep strain [G1 genotype] occurs in Iran. A wide variety of livestock including sheep, cattle, goat, camel and buffalo also harbor the disease. E. multilocularis another agent of human hydatidosis [alveolar cyst] is reported here as well and from 1946 to 1993, 37 cases of human alveolar echinococcosis were reported from northwestern Iran. Hydatidosis must be considered as a dilemma in Iran because of its endemicity in the country

Impact of overgrazing on the transmission of Echinococcus multilocularis in Tibetan pastoral communities of Sichuan Province, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Overgrazing was assumed to increase the population density of small mammals that are the intermediate hosts of Echinococcus multilocularis, the pathogen of alveolar echinococcosis in the Qinghai Tibet Plateau. This research tested the hypothesis that overgrazing might promote Echinococcus multilocularis transmission through increasing populations of small mammal, intermediate hosts in Tibetan pastoral communities.</p><p><b>METHODS</b>Grazing practices, small mammal indices and dog Echinococcus multilocularis infection data were collected to analyze the relation between overgrazing and Echinococcus multilocularis transmission using nonparametric tests and multiple stepwise logistic regression.</p><p><b>RESULTS</b>In the investigated area, raising livestock was a key industry. The communal pastures existed and the available forage was deficient for grazing. Open (common) pastures were overgrazed and had higher burrow density of small mammals compared with neighboring fenced (private) pastures; this high overgrazing pressure on the open pastures measured by neighboring fenced area led to higher burrow density of small mammals in open pastures. The median burrow density of small mammals in open pastures was independently associated with nearby canine Echinococcus multilocularis infection (P = 0.003, OR = 1.048).</p><p><b>CONCLUSION</b>Overgrazing may promote the transmission of Echinococcus multilocularis through increasing the population density of small mammals.</p>

Immunoperoxidase staining of alveolar hydatid cyst from an experimentally infected gerbil.

Echinococcus multilocularis, the small fox tapeworm, has an extensive geographical range in the northern hemisphere where foxes and small rodents represent natural hosts. The larval stage of this parasite, alveolar echinococcosis (AE), is an emerging zoonosis of increasing importance. It is a serious human illness which is often misdiagnosed as hepatic cancer. If not identified at an early stage of parasite development it can lead to the death of patients. Histological examination of biopsies is one of the classical methods of diagnosis. In this study, in order to gain unequivocal histopathological diagnosis of AE, the immunoperoxidase staining technique was performed on routinely processed histological sections of an experimentally infected gerbil, using rabbit anti-E. multilocularis protoscolex IgG labelled with horseradish peroxidase. Demonstration of AE antigen was achieved by dark brown stain of cyst membranes against a blue background of the host liver cells stained with hematoxylin.