Cases Of Alveolar Echinococcosis Research Articles

A Case Series and Literature Review of Alveolar Echinococcosis in Kashmir, India: An Emerging Endemic Zone for Echinococcus multilocularis.

A prospective study on 110 patients with echinococcosis at Dr. Khuroo's Medical Clinic, Srinagar, Kashmir, India, from March 2019 to April 2024 identified 12 cases (4 males, 8 females; mean age of 46.58 ± 11.97 years) of Alveolar echinococcosis (AE). Two patients were detected through ultrasound examinations carried out for unrelated causes; one presented with features of liver abscess, and nine had pain in the right upper quadrant for a mean period of 2.2 ± 1.79 years. All had the liver as the primary organ involved, with 15 tumor masses of a mean maximum diameter of 9.22 ± 3.21 cm and volume of 426 ± 374.61 cm3. Tumors placed centrally had invaded vessels and the biliary tract in eight patients, and those placed peripherally had invaded the liver capsule and adjacent organs in nine patients. Histologic examination of liver biopsies or resected organs revealed necrotic lesions, calcifications, and granulomatous inflammation with slender, thin-walled vesicles of bizarre configuration that stained strongly eosinophilic with periodic acid Schiff. Two patients had segmental liver resections; one was treated with liver aspiration, while the other nine with advanced disease received chemotherapy with albendazole along with praziquantel. Patients showed clinical improvement on a median follow-up of 12 months (range 1 to 60 months); however, MRI T2-weighted images and 18F-FDG-PET-CECT scans in two patients showed active disease on follow-up at one and five years, respectively. A systematic review detected 146 cases of AE in India from 1980 to April 2024. Twenty cases were from foreign countries, mostly from Central Asian republics, and 118 (93.65%) of the remaining 126 Indian patients were permanent residents of Kashmir Valley. The disease affected a population of 79,197 residing in 22 villages from 5 border districts of the valley. These villages were either high in or adjacent to the Himalayan mountain range. Disease prevalence in the affected population was 146.47/105 (males 131.53/105 and females 163.18/105) and the incidence was 12.41/105/year (males 11.16/105/year and females 13.81/105/year). Possible causes of the emergence of AE are discussed, and future directions for research to face this challenge arebeen identified.

Construction and application of a risk index of Echinococcus infection based on the classification of echinococcosis lesions

To investigate the feasibility of constructing the risk index of Echinococcus infection based on the classification of echinococcosis lesions, so as to provide insights into the management of echinococcosis. The imaging data of echinococcosis cases were collected from epidemiological surveys of echinococcosis in China from 2012 to 2016, and the detection of incident echinococcosis cases was captured from the annual echinococcosis prevention and control reports across provinces (autonomous regions) and Xinjiang Production and Construction Corps in China from 2017 to 2022. After echinococcosis lesions were classified, a risk index of Echinococcus infection was constructed based on the principle of discrete distribution marginal probability and multi-group classification data tests. The correlation between the risk index of Echinococcus infection and the detection of incident echinococcosis cases was evaluated in the provinces (autonomous regions and corps) from 2017 to 2022, and the correlations between the short and medium-term risk indices and between the medium and long-term risk indices of Echinococcus infection were examined using a univariate linear regression model. A total of 4 014 echinococcosis cases in China from 2012 to 2016 were included in this study. The short-, medium- and long-term risk indices of E. granulosus infection varied in echinococcosis-endemic provinces (autonomous regions and corps) of China (χ2 = 4.12 to 708.65, all P values < 0.05), with high short- (0.058), medium- (0.137) and long-term risk indices (0.104) in Tibet Autonomous Region, and the short-, medium- and long-term risk indices of E. multilocularis infection varied in echinococcosis-endemic provinces (autonomous regions and corps) of China (χ2 = 6.74 to 122.60, all P values < 0.05), with a high short-term risk index in Sichuan Province (0.016) and high medium- (0.009) and long-term risk indices in Qinghai Province (0.018). There were no significant correlations between the risk index of E. granulosus infection and the detection of incident cystic echinococcosis cases during the study period (t = -0.518 to 2.265, all P values > 0.05), and strong correlations were found between the risk indices of E. multilocularis infection and the detection of incident alveolar echinococcosis cases (including mixed type) in 2018, 2020, 2021, 2022, during the period from 2017 through 2020, from 2017 through 2021, from 2017 through 2022 (all r values > 0.7, t = 2.521 to 3.692, all P values < 0.05). Linear regression models were established between the risk index of E. multilocular infection and the detection of alveolar echinococcosis cases (including mixed type), and the models were all statistically significant (b = 0.214 to 2.168, t = 2.458 to 3.692, F = 6.044 to 13.629, all P values < 0.05). The regression coefficients for the correlations between the medium- and short-term, and between the long- and medium-term risk indices of E. granulosus infection were 2.339 and 0.765, and the regression coefficients for the correlations between the medium- and short-term, and between the long- and medium-term risk indices of E. multilocular infection were 0.280 and 1.842, with statistical significance seen in both the regression coefficients and regression models (t = 16.479 to 197.304, F = 271.570 to 38 928.860, all P values < 0.05). The risk index of Echinococcus infection has been successfully established based on the classification of echinococcosis lesions, which may provide insights into the prevention and control, prediction, diagnosis and treatment, and classified management of echinococcosis.

Human alveolar echinococcosis in Slovakia: Epidemiology and genetic diversity of Echinococcus multilocularis, 2000-2023.

Human alveolar echinococcosis (AE) is a serious parasitic disease caused by larval stages of Echinococcus multilocularis. Between January 2000 and October 2023, 137 AE cases were confirmed in Slovakia. The average annual incidence increased from 0.031 per 100,000 inhabitants between 2000 and 2011, to an average of 0.187 since 2012, i.e. about six times. Among patients, 45.3% were men and 54.7% were women; the mean age at the time of diagnosis was 52.8 years. Most cases were diagnosed in the age groups 51-60 years and 61-70 years (33 cases each), and eight patients fell into the age category ≤ 20 years. To better recognize the gene diversity in clinical samples, metacestodes from 21 patients collected between 2013 and 2021 were subjected to DNA sequencing of four mitochondrial genes. Using concatenated sequences of cob (603 bp), nad2 (882 bp) and cox1 (789 bp) gene fragments, 14 isolates (66.7%) were assigned to the European E5 profile of E. multilocularis, two isolates (9.5%) to the E5a subtype, four isolates (19%) to the E4 profile, and one isolate (4.8%) to haplogroup E1/E2. The E5-type profiles and E4 profiles were distributed throughout the country, whereas the E1/E2 profile was found in the patient from western Slovakia. According to the data obtained and GenBank sequences, the E5-type dispersal is so far limited to central-eastern Europe and the variant seems to be indigenous to that region. The admixture with the haplotypes E4 and E1/E2 could have taken place from a historical endemic focus during the fox expansion in the last decades. By employing the nad1 fragment, a typical European haplotype was observed in all 21 resolved Slovak samples. The acceleration in the AE incidence in the last decade suggests the emergence of the disease and the need for further research on human and animal isolates.

Echinococcus multilocularis and other zoonotic helminths in red foxes (Vulpes vulpes) from a southern German hotspot for human alveolar echinococcosis

BackgroundWe describe the spatial distribution of Echinococcus multilocularis in its main definitive host, the red fox, and the distribution of human cases of alveolar echinococcosis (AE) within a highly endemic focus in southern Germany (13.7–19.9/100,000 in 1992–2018). Human cases were unequally distributed within the endemicity focus. The purpose of the study was to test whether this is reflected in the small-scale distribution of E. multilocularis in foxes.MethodsThree areas with contrasting numbers of human cases were selected within the counties of Ravensburg and Alb-Donau, Baden-Württemberg, Germany. From 2018 to 2020, a total of 240 fox carcasses were obtained from traditional hunters in these areas. Carcasses were necropsied and examined for the presence of intestinal helminths. The statistical analysis was performed with SAS version 9.4, and the geo-mapping with QGIS version 3.16.0 Hannover.ResultsThe prevalence of E. multilocularis in foxes was 44/106 (41.5%) in area I (commune Leutkirch and environs), 30/59 (50.8%) in area II (commune Isny and environs), and 31/75 (41.3%) in area III (commune Ehingen and environs). From 1992 to 2018, a total of nine human cases of alveolar echinococcosis were recorded in area I, five cases were recorded in study area III, and no cases were recorded in area II. No statistically significant differences between the areas were observed (P > 0.05) for intestinal infections with E. multilocularis, and no apparent spatial correlation with the small-scale distribution of human cases was found. Concerning other zoonotic helminths, Toxocara spp. were equally common, with prevalence of 38.7%, 47.4% and 48.0%, respectively, while the frequency of Alaria alata varied among the study areas (0.0–9.4%), probably reflecting the specific habitat requirements for the establishment of its complex life cycle.ConclusionsEchinococcus multilocularis is highly prevalent in foxes in all the studied areas. The varying number of human AE cases within these areas should therefore be caused by factors other than the intensity of parasite transmission in foxes.Graphical

Virtual non-enhanced dual-energy computed tomography reconstruction: a candidate to replace true non-enhanced computed tomography scans in the setting of suspected liver alveolar echinococcosis.

When a suspected hepatic alveolar echinococcosis (AE) lesion is detected on a contrast enhanced computed tomography (CT) scan, an additional triphasic or non-enhanced CT scan is required to determine the presence of calcification and enhancement. As a result, imaging costs and exposure to ionizing radiation will increase. We can create a non-enhanced series from routine contrast-enhanced images using dual-energy CT (DECT) and virtual non-enhanced (VNE) images. This study's objective is to assess virtual non-enhanced DECT reconstruction as a potential diagnostic tool for hepatic AE. Triphasic CT scans and a routine dual energy venous phase were acquired using a third-generation DECT system. A commercially available software package was used to generate VNE images. Individual evaluations were conducted by two radiologists. The study population consisted of 100 patients (30 AE, 70 other solid liver masses). All AE cases were diagnosed [no false positives/negatives, 95% confidence interval (CI) sensitivity: 91.3%-100%; 95% CI specificity: 95.3%-100%]. Interrater agreement was k: 0.79. In total, 33 (33.00%) of the patients had AE, which was detected using both true non-enhanced (TNE) and VNE images. The mean dose-length product of a standard triphasic CT was significantly higher than biphasic dual-energy VNE images. In terms of diagnostic confidence, VNE images are comparable with actual non-enhanced imaging when evaluating hepatic AE. Further, VNE images could replace TNE images with a substantial radiation dose reduction. Advances in knowledge: hepatic cystic echinococcosis and AE are serious and severe diseases with high fatality rates and a poor prognosis if managed incorrectly, especially AE. Moreover, VNE images produce equal diagnostic confidence to TNE images for assessing liver AE, with a significant reduction in radiation dose.

First cases of alveolar echinococcosis in dogs in Poland.

Alveolar echinococcosis caused by Echinococcus multilocularis is common parasitic disease among humans and animals in the northern hemisphere. Dogs, foxes, and other wild canids are definitive hosts, whereas small rodents play the role of intermediate hosts. In rare cases, after incidental ingestion of tapeworm eggs, dogs can become an intermediate host. The study describes briefly two cases of alveolar echinococcosis in dogs in Poland, including clinical management, diagnostic, treatment and molecular confirmation. Diagnostic procedures included laparotomy, cytology, histopathology and molecular analysis. Obtained sequences data were 100% homologous to E. multilocularis dehydrogenase subunit 1 gene sequences in GenBank®. To the authors' knowledge, alveolar echinococcosis has not been reported previously in a dog in Poland.

It's a small world for parasites: evidence supporting the North American invasion of European Echinococcus multilocularis.

Echinococcus multilocularis (Em), the causative agent of human alveolar echinococcosis (AE), is present in the Holarctic region, and several genetic variants deem to have differential infectivity and pathogenicity. An unprecedented outbreak of human AE cases in Western Canada infected with a European-like strain circulating in wild hosts warranted assessment of whether this strain was derived from a recent invasion or was endemic but undetected. Using nuclear and mitochondrial markers, we investigated the genetic diversity of Em in wild coyotes and red foxes from Western Canada, compared the genetic variants identified to global isolates and assessed their spatial distribution to infer possible invasion dynamics. Genetic variants from Western Canada were closely related to the original European clade, with lesser genetic diversity than that expected for a long-established strain and spatial genetic discontinuities within the study area, supporting the hypothesis of a relatively recent invasion with various founder events.

Canine Alveolar Echinococcosis: An Emerging and Costly Introduced Problem in North America

Alveolar echinococcosis (AE), caused by the metacestode of Echinococcus multilocularis, is emerging in both dogs and people in North America. Here, we review 27 cases of canine AE opportunistically reported since the index case was described in 2009 in Western Canada. We describe clinical presentation, diagnosis, treatment, outcome, and source of canine infection, based on genetics of the parasite isolated from some canine cases. Diagnosis of AE was by histopathology and/or PCR on DNA extracted from metacestodes. The median age of dogs at diagnosis was 4 years (range 1–12), which is low compared to neoplasia, the most common differential diagnosis. There was no sex predilection and different breeds were involved, but there were a disproportionate number of boxers and beagles relative to their representation in the general canine population. The most common potential risk factors included contact with wildlife and visits to off leash areas. Abdominal distension was the most common clinical sign at presentation, and medical imaging generally revealed an abdominal mass. On histopathology, protoscoleces were observed in 7 out of 14 dogs. In 7 cases, DNA sequences were most similar to European (versus North American) haplotypes, identical to those recently reported in coyotes as definitive hosts in North America, and different between eastern and western North America, implying multiple introduction events. Dogs that were not treated (n = 6) had 16% survival in the first 100 days in comparison with 82% survival of treated dogs (n = 11). Direct costs to the owner of treating canine AE ranged from 1,317 to 12,655 CAD depending on the situation at the onset of treatment. This study provides important clinical, epidemiological, and economic information for veterinary practitioners and regulators for importation of dogs, and for public health, as dogs with AE may serve as indicators of parasite range expansion and risk to humans.

CT Imaging Findings of Pulmonary Alveolar Echinococcosis.

Alveolar echinococcosis is a parasitic infection caused by Echinococcus multilocularis in the metacestode stage. The disease involves the liver in almost all cases, and additionally, lung involvement is accompanied in approximately 13% of the cases. Due to the low incidence of pulmonary alveolar echinococci, there are few case reports of lung involvement in the literature. In this study, computed tomography (CT) findings related to pulmonary involvement in alveolar echinococcosis cases, which have increased worldwide in recent years, were evaluated.

Alveolar echinococcosis in solid organ transplant recipients: a case series from two national cohorts.

Alveolar echinococcosis (AE) is a severe parasitic infection caused by the ingestion of Echinococcus multilocularis eggs. While higher incidence and faster evolution have been reported in immunosuppressed patients, no studies have been performed specifically on AE in transplant patients. We searched for all de novo AE cases diagnosed between January 2008 and August 2018 in solid organ transplant (SOT) recipients included in the Swiss Transplant Cohort Study and the FrancEchino Registry. Eight cases were identified (kidney=5, lung=2, heart=1, liver=0), half of which were asymptomatic at diagnosis. AE diagnosis was difficult due to the low sensitivity (60%) of the standard screening serology (Em2+) and the frequently atypical radiological presentations. Conversely, Echinococcus Western blot retained good diagnostic performances and was positive in all eight cases. Five patients underwent surgery, but complete resection could only be achieved in one case. Moreover, two patients died of peri-operative complications. Albendazole was initiated in seven patients and was well tolerated. Overall, AE regressed in one, stabilized in three, and progressed in one case, and had an overall mortality of 37.5% (3/8 patients). Our data suggest that AE has a higher mortality and a faster clinical course in SOT recipients; they also suggest that the parasitic disease might be due to the reactivation of latent microscopic liver lesions through immune suppression. Western blot serology should be preferred in this population. Finally, surgery should be considered with caution, because of its low success rate and high mortality, and conservative treatment with albendazole is well tolerated.

Comparison of local ablation with Albendazole or laparoscopic hepatectomy combined with Albendazole in the treatment of early hepatic alveolar echinococcosis.

BackgroundEchinococcosis (E) is a zoonotic parasitic disease caused by the larval morphology of echinococcosis tapeworms. Among the recognized species, two are of medical importance—E. granulosus and E. multilocularis—causing cystic echinococcosis (CE) and alveolar echinococcosis (AE) in humans, respectively. Diagnosis of AE is based on clinical manifestation and epidemiological data, imaging techniques, histopathology and/or nucleic acid detection, and serology. At present, WHO guidelines suggest that benzimidazoles (BMZ) are mandatory in all AE patients, temporarily after complete resection of the lesions and for life in all other AE cases. Interventional procedures should be preferred to palliative surgery whenever possible, and radical surgery is the first choice in all cases suitable for total resection of the lesion. However, some research centers have proposed that local ablation (LA) including radiofrequency ablation (RFA) and microwave ablation (MWA) is no less effective than radical surgery or better than simple medication in the early stage hepatic AE (WHO-IWGE PNM classification of AE: P1N0M0). This study attempted to compare the real efficacy of the above treatment methods, so as to find the best treatment for this kind of patient.MethodsThe data of patients with hepatic AE who underwent laparoscopic hepatectomy (LH), RFA, and MWA in Qinghai Provincial People's Hospital from January 2015 to January 2021 were collected. At the same time, the cases treated with Albendazole (ABZ) were collected together with the institution for disease control and prevention. According to the treatment methods, the above cases were divided into LH group, RFA group, MWA group, and medication group. The basic data and postoperative recovery indices of the four groups were compared, respectively.ResultsA total of 199 patients with hepatic AE were enrolled in this study, including 90 males and 109 females. The youngest was 5 years old and the oldest was 66 years old, with an average of 33.41±14.64 years old. 20.6% of the patients had hepatitis B (41/ 199). A total of 45 patients underwent ultrasound-guided RFA, 47 patients underwent ultrasound-guided MWA, 51 patients were treated with ABZ, and 56 patients underwent LH. There were no significant differences in baseline characteristics among the four groups (p > 0.05). The RFA group and MWA group were more advantageous than the LH group regarding operation time and incidence of postoperative complications (p < 0.05). But recurrence rate of the lesion in the LH group was significantly lower than the RFA group, MWA group, and medication group. However, there was no significant difference in recurrence-free survival time among the four groups (p >0.05).ConclusionLH has a significant effect in the treatment of early-stage hepatic AE, especially in terms of recurrence which is significantly better than LA and medication alone. Follow-up and adherence to ABZ therapy are essential if conservative treatment is to achieve better outcomes.

The impact of natural environment on human alveolar echinococcosis: A township-level modeling study in Qinghai-Tibet Plateau

Human alveolar echinococcosis (AE) is a lethal helminthic infection caused by the tapeworms Echinococcus multilocularis. The Qinghai-Tibet Plateau has the greatest endemicity of human AE globally, but the natural risk factors and its impact mechanism are still unclear. Generalized linear models and generalized additive models are used to select key linear and non-linear environmental factors associated with cases of AE. The interactive effect between different factors is identified using concurvity test. From fifty-nine variables analyzed, four key factors and one interaction term were identified associated with AE. Considering interaction terms between climatic and geographical landscape factors can significantly improve model fitting. Minimum winter precipitation, percentage of grassland cover, and minimum elevation have significant positive linear relationship with human AE incidence. The relationship between maximum summer precipitation and human AE is non-linear with high AE incidence associated with moderate precipitation. The interaction term of maximum summer precipitation and number of patches of grassland on human AE indicates that human AE incidence is highest when both factors were high. The climatic and landscape risk factors together are associated with the local transmission of human AE in Qinghai-Tibet Plateau. This study provides a scientific basis for human intervention in AE from fine-scale ecological environment.

Characteristics and Clinical Course of Alveolar Echinococcosis in Patients with Immunosuppression-Associated Conditions: A Retrospective Cohort Study.

Objectives: Since the change in the millennium, an increase in cases of alveolar echinococcosis (AE) has been observed in endemic European countries. Previous studies indicate that a significant proportion of the new AE cases have an immunosuppression-associated condition (IAC). The aim of the current study was to determine how IACs impact the number of new AE diagnoses per year and the characteristics of AE at diagnosis and its clinical course at our center. Methods: Retrospective analysis of 189 patients with AE diagnosed between 2000 and 2021 and participating in the Zurich Echinococcosis Cohort Study (ZECS) included clinical characteristics of AE at diagnosis and report of an IAC, as well as the clinical course during follow-up. Results: Of 189 patients participating in this study, 38 had an IAC reported at, or shortly after, AE diagnosis. Over time, there was a steeper increase in the number of newly diagnosed AE patients without an IAC than the number of patients with IAC. Patients with an IAC were older at diagnosis, more frequently had an incidental finding of AE, smaller mean lesion size, and negative Em18 serology. All but two showed favorable outcomes on the last follow-up. Conclusion: IACs have little impact on the increase in new AE cases, as well as on the extent of the disease at diagnosis and clinical course.

Echinococcus granulosus Protoscolex DM9 Protein Shows High Potential for Serodiagnosis of Alveolar Echinococcosis.

Alveolar echinococcosis (AE) caused by infection with E. multilocularis metacestode, represents one of the most fatal helminthic diseases. AE is principally manifested with infiltrative, proliferating hepatic mass, resembling primary hepatocellular carcinoma. Sometimes metastatic lesions are found in nearby or remote tissue. AE diagnosis largely depends on imaging studies, but atypical findings of imaging features frequently require differential diagnosis from other hepatic lesions. Serological tests may provide further evidence, while obtaining reliable AE materials is not easy. In this study, alternative antigens, specific to AE were identified by analyzing E. granulosus protoscolex proteins. An immunoblot analysis of E. granulosus protoscolex showed that a group of low-molecular-weight proteins in the range from 14 kDa to 16 kDa exhibited a sensitive and specific immune response to AE patient sera. Partial purification and proteomic analysis indicated that this protein group contained myosin, tubulin polymerization promoting protein, fatty-acid binding protein, uncharacterized DM9, heat shock protein 90 cochaperone tebp P-23, and antigen S. When the serological applicability of recombinant forms of these proteins was assessed using enzyme-linked immunosorbent assay, DM9 protein (rEgDM9) showed 90.1% sensitivity (73/81 sera tested) and 94.5% specificity (172/181 sera tested), respectively. rEgDM9 showed weak cross-reactions with patient sera from the transitional and chronic stages of cystic echinococcosis (3 to 5 stages). rEgDM9 would serve as a useful alternative antigen for serodiagnosis of both early- and advanced-stage AE cases.

Spread and Development of Alveolar Echinococcosis in Germany, 1992-2018

Alveolar echinococcosis (AE) is a rare parasitosis caused by the pathogen Echinococcus multilocularis. There is an increase in the number of cases in many countries. The aim of the study was to investigate the current prevalence and the change in the geographical distribution pattern. Data were collected retrospectively for the period 1992-2018 using the registered cases in the national disease register for AE in Germany. Statistical analysis was performed using the SAS statistical analysis system version 9.4 (SAS Institute, Cary, N.C., USA). The study population of n=569 patients included n=322 (56,59%) women and n=247 (43,40%) men. The mean average age of patients with alveolar echinococcosis at first presentation was 53,90±17,54 years (median: 56,00 years). The Moran's I test statistic showed a positive spatial autocorrelation for the period 1992-2018 corresponding to a heterogeneous distribution of disease cases in Germany (I=0,4165; Z=10,9591, p=0,001). An increase in age- and sex-specific prevalence could be determined for the entire study period (1992-2018). The overall prevalence in the period 1992-2018 was 0,71 cases per 100,000 population. The determination of the prevalence for the period 1992-2018 resulted in 0,31 cases for men and 0,40 cases for women per 100,000 population. In the period 1992-1996, no AE cases had been registered in 11/16 (68,8%) federal states (Berlin, Brandenburg, Bremen, Hamburg, Mecklenburg-Vorpommern, Rheinland-Pfalz, Saarland, Sachsen, Sachsen-Anhalt, Schleswig-Holstein und Thüringen). The evaluation recently shows an increased occurrence of cases in the federal states of Hessen, Rheinland-Pfalz and Nordrhein-Westfalen. The analysis shows a rise in prevalence and an increasing number of cases outside the classic endemic areas of Baden-Württemberg and Bavaria.

Epidemiology of human alveolar echinococcosis in Armenia

Abstract Background Since the 90s' E.multilocularis infection in foxes is rising and central-eastern European countries had seen first Alveolar echinococcosis (AE) human cases. AE is considered to be a very rare disease in Europe with average incidences of 0.03-0.20/100,000 inhabitants/year. Because of a suitable orography, this study aims to confirm whether there are human AE cases in Armenia, identify areas at risk, and also estimate AE annual incidence. Methods Retrospective AE case finding was carried out at main 6 multi-profile medical centers equipped with the most innovative diagnostic means. The medical records of all patients with liver surgery admitted between January 2008 and June 2020 were reviewed. A specific form was developed in EpiInfo v. 7.2. Annual national incidence was estimated using population denominators provided by the National Institute of Statistics (the population of Armenia is estimated at 2 963 243 people). Results From September 2019 until June 2020, overall 11 AE cases have been identified. All patients were diagnosed at advanced stages, with subsequent poor prognosis and costly treatment. Confirmation was based on tissue biopsy results. Age ranged from 19-59 years with a median of 39yrs. E. multilocularis was detected in rural communities, mostly in the Gegharkunik region (6 cases, 55%). Annual average incidence of AE was 0.033 varying between 0.032 in 2008 and 0.1 in 2017. For comparison with Armenia, an annual incidence in France was 0.026/100,000 in 2008 (the population of France is estimated at 65 273 511 people). Conclusions All cases were not notified by the surveillance system and the real prevalence of AE in the country is unknown. This young age could indicate widespread of infection in animals. Therefore, the burden of AE disease is difficult to estimate. The surveillance system in Armenia can be improved by the development of national guidelines for the prospective registry, AE awareness campaigns. Key messages First-time identification of human AE in Armenia calls for implementation of surveillance with a case definition and registry of all cases. AE is an emerging, and so far silent threat in Armenia.

Alveolar echinococcosis: what triggers emergence in North America, Central Europe and Asia?

Infection with the larval (metacestode) stage of Echinococcus multilocularis causes alveolar echinococcosis (AE), a serious hepatic disorder. The parasite has increased its infection extensity in wildlife and domestic dogs, mainly due to urbanization and spatial extension of wildlife hosts in Europe, Asia as well as North America, resulting in emerging infection risk for humans. In hyperendemic areas such as Kyrgyzstan and China, ecological and socioeconomic changes have been associated with the unpredictable increase of AE cases. In North America, the appearance of the European-like genotype is of concern. In Europe, the annual increase of human case numbers reached a plateau even in hyperendemic situations. Therefore, we conclude that most of the exposed individuals are resistant to parasite invasion and/or to disease development. Thus, AE develops in a few healthy individuals, but preferentially in immunosuppressed patients. In the future, improved diagnostic strategies will allow more precise estimations of transmission routes including the role of food, water and direct dog contact, which should yield improved public health recommendations. Finally, understanding protective innate and acquired immune mechanisms as well as parasite-driven immune-evasion processes will be essential to develop curative therapies in nonoperable patients and, futuristically, appropriate vaccines.

Epidemiological analysis of cystic echinococcosis and alveolar echinococcosis in an extremely high prevalence region: Population-based survey and host animal monitoring in Shiqu County, China

Echinococcosis is the most common parasitic disease in the Tibetan Plateau, placing a large disease burden on the local population. Shiqu County, located in western Sichuan Tibetan region, had a particularly high prevalence rate of cystic echinococcosis (CE) and alveolar echinococcosis (AE) in previous surveys. From 2015 to 2018, a population-based field survey was conducted to explore the epidemic situation. Epidemiological features were examined through demographic analysis and mapping. In addition, the infection prevalence of Echinococcus in dogs was also investigated and mapped by spatial autoregression. A total of 84,768 people were screened by abdominal ultrasound inspection, and 2,341 CE and 3,930 AE cases were detected, with a corresponding prevalence of 2.76% and 4.64%, respectively. This made Shiqu County one of the most severe echinococcosis endemic regions in the world, especially with regard to AE. The cases were not evenly distributed among towns: particularly, the AE rates in the northwest towns were very high and closely related to the infection rate of neighboring host animals. Simultaneously, a comprehensive prevention project including patient treatment and host management was conducted and achieved preliminary success in source control. According to feces monitoring findings, the infection rate of dogs declined from 26.38% in early 2016 to 3.71% in 2018. Combined with host animal distribution data at the town level, the predicted risk ranks were categorized by risk index and mapped to guide further control operations.

High endemicity of alveolar echinococcosis in Yili Prefecture, Xinjiang Autonomous Region, the People's Republic of China: Infection status in different ethnic communities and in small mammals.

Alveolar echinococcosis (AE) is a life-threatening disease in humans caused by the larval stage of Echinococcus multilocularis. The tapeworm is transmitted between small mammals and dogs/foxes in the Northern Hemisphere. In this study 286 AE cases were reported from eight counties and one city in Yili Prefecture, Xinjiang Autonomous Region, the People's Republic of China from 1989 to 2015 with an annual incidence (AI) of 0.41/100,000. Among the patients, 73.08% were diagnosed in the last 11 years. Four counties in the high mountainous areas showed higher AI (0.51-1.22 cases/100,000 residents) than the four counties in low level areas (0.19-0.29/100,000 residents). The AI of AE in Mongolian (2.06/100,000 residents) and Kazak (0.93/100,000 residents) ethnic groups was higher than the incidence in other ethnic groups indicating sheep-farming is a risk for infection given this activity is mainly practiced by these two groups in the prefecture. A total of 1411 small mammals were captured with 9.14% infected with E. multilocularis metacestodes. Microtus obscurus was the dominant species in the mountain pasture areas with 15.01% of the voles infected, whereas Mus musculus and Apodemus sylvaticus were the dominant small mammals in the low altitude areas. Only 0.40% of A. sylvaticus were infected with E. multilocularis. PCR amplification and sequencing analysis of the mitochondrial cox1 gene showed that E. multilocularis DNA sequences from the small mammals were identical to isolates of local human AE cases. The overall results show that Yili Prefecture is a highly endemic area for AE and that the high-altitude pasture areas favorable for M. obscurus may play an important role in its transmission in this region.

Transplantation and autotransplantation of the liver in radical treatment of unresectable liver tumors and parasitic diseases

Aim. To evaluate results of liver transplantation and ex situ liver resection and autotransplantation in patients with unresectable parasitic and tumor liver lesions. Matherial and methods. A total of 22 orthotopic liver transplants and 4 ex situ liver resection and autotransplantations were performed. Liver transplants performed in 10 cases of unresectable hepatocellular carcinoma, 8 cases of alveolar echinococcosis, 4 cases of hepatic epithelioid haemangioendothelioma. Ex situ liver resection and autotransplantation were performed in 3 cases of alveolar echinococcosis and in 1 case of cholangiocarcinoma. Results. Postoperative complication developed in 38,4% patients. Mortality rate was 19.2%. Patients with alveolar echinococcosis were most complicated group with 36,3% early mortality rate. Mortality in hepatocellular carcinoma group was 10%. There were no early mortality in haemangioendothelioma and cholangiocarcinoma patients. Median overall survival for hepatocelluler carcinoma, alveolar echinococcosis and hepatic epithelioid haemangioendothelioma groups was 48, 36, 20 months respectively. Patient after ex situ liver resection for cholangiocarcinoma alive for 24 months and still disease free. Conclusion. Liver transplantation and ex situ liver resection and autotransplantation is the only opportunity for radical treatment for unresectable alveolar echinococcosis and some oncological diseases of the organ. Patients with unresectable alveolar echinococcosis is a high risk group of postoperative complications due to initial poor physical status, long-time disease, chronically infections and parasitic invasion.