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

[Clinical Features and Surgical Outcomes of 15 Cases of Intracranial Alveolar Echinococcosis]

Objective

To investigate the surgical treatment strategy of intracranial alveolar echinococcosis (AE) and the clinical outcomes.

Methods

The clinical and follow-up data of 15 intracranial AE patients who underwent surgical treatment in the Departments of Neurosurgery of Sichuan Provincial People's Hospital (SPPH) and People's Hospital of Aba Tibetan and Qiang Autonomous Prefecture (a branch hospital of SPPH) between March 2017 and January 2021 were retrospectively analyzed. Full follow-up data were available for each of the 15 cases. The clinical and imaging characteristics, general surgical information, and surgical outcomes were analyzed.

Results

In the 15 patients, there were a total of 50 intracranial lesions, with an average of (3.3±3.1)/case. Four cases had solitary intracranial lesions, while 11 cases had multiple lesions, with the number of intracranial lesions per case ranging from 2 to 13. All patients with solitary intracranial lesions received total resection. In 6 patients with multiple intracranial lesions, only the largest lesion was surgically removed, and in 5 patients, 2 to 3 adjacent lesions were surgically removed. All but one patient had extracranial lesions in their liver, lungs, kidneys, adrenal glands, and thoracic vertebrae. The patients were followed up for 12 to 58 months after surgery, with the mean follow-up time being (28.1±13.4) months. Among the 15 cases, 13 showed stable intracranial condition during postoperative follow-up. Intracranial lesions recurred in 2 patients who had deep lesions accompanied by dissemination to the subarachnoid space. Two patients died during follow-up.

Conclusion

Microsurgical treatment of intracranial AE is effective, but total surgical resection is difficult to accomplish when patients have echinococcosis lesions located at a depth, especially when the lesions are spreading to the subarachnoid space. The prognosis of patients is closely associated with the extent of lesion invasion and the control of systemic hydatid lesions, especially those in the liver.

Management of biliary obstruction in patients with newly diagnosed alveolar echinococcosis: a Swiss retrospective cohort study

BACKGROUND AND STUDY AIMS

Alveolar echinococcosis, an orphan zoonosis affecting the liver, is of increasing concern worldwide. Most symptomatic cases present at an advanced and inoperable stage, sometimes with biliary obstruction prompting biliary tract interventions. These are, however, associated with a high risk of infectious complications. The aim of this retrospective study was to compare the effectiveness and safety of conservative and interventional treatment approaches in patients with newly diagnosed alveolar echinococcosis and biliary obstruction.

PATIENTS AND METHODS

Alveolar echinococcosis patients treated at two referral centres in Switzerland, presenting with hyperbilirubinaemia (total bilirubin >1.5 Upper Limit of Normal) at diagnosis were included, unless another underlying aetiology, i.e. common bile duct stones or decompensated cirrhosis, was identified. Patients were divided into two groups, according to whether they initially received a biliary tract intervention. The primary endpoint was normalisation of bilirubin levels within a 6-month period. Secondary endpoints included, among others, the occurrence of early and late biliary complications, the need for biliary tract interventions during follow-up and overall duration of hospital stays for treatment initiation and for biliary complications.

RESULTS

28 patients were included in this study, of whom 17 received benzimidazole therapy alone and 11 additionally received a biliary tract intervention. Baseline characteristics did not differ between groups. All but one patient in each group achieved the primary endpoint (p=0.747). Biliary tract intervention was associated with faster laboratory improvement (t1/2 1.3 vs 3.0 weeks), but also with more frequent early biliary complications (7/11 vs 1/17, p=0.002) and longer initial hospital stay (18 days vs 7 days, p=0.007).

CONCLUSION

Biliary obstruction in patients with newly diagnosed alveolar echinococcosis can be treated effectively with benzimidazole therapy alone. Biliary tract intervention, on the other hand, is associated with a high complication rate and should probably be reserved for patients with insufficient response to benzimidazole therapy.

Complete mitochondrial exploration of Echinococcus multilocularis from French alveolar echinococcosis patients

Alveolar echinococcosis (AE) is a parasitosis that is expanding worldwide, including in Europe. The development of genotypic markers is essential to follow its spatiotemporal evolution. Sequencing of the commonly used mitochondrial genes cob, cox1, and nad2 shows low discriminatory power, and analysis of the microsatellite marker EmsB does not allow nucleotide sequence analysis. We aimed to develop a new method for the genotyping of Echinococcus multilocularis based on whole mitochondrial genome (mitogenome) sequencing, to determine the genetic diversity among 30 human visceral samples from French patients, and compare this method with those currently in use. Sequencing of the whole mitochondrial genome was carried out after amplification by PCR, using one uniplex and two multiplex reactions to cover the 13,738 bp of the mitogenome, combined with Illumina technology. Thirty complete mitogenome sequences were obtained from AE lesions. One showed strong identity with Asian genotypes (99.98% identity) in a patient who had travelled to China. The other 29 mitogenomes could be differentiated into 13 haplotypes, showing higher haplotype and nucleotide diversity than when using the cob, cox1, and nad2 gene sequences alone. The mitochondrial genotyping data and EmsB profiles did not overlap, probably because one method uses the mitochondrial genome and the other the nuclear genome. The pairwise fixation index (F_st) value between individuals living inside and those living outside the endemic area was high (F_st = 0.222, P = 0.002). This is consistent with the hypothesis of an expansion from historical endemic areas to peripheral regions.

Risk Factors and the Character of Clinical Course of the Echinococcus multilocularis Infection in Patients in Poland

Alveolar echinococcosis (AE) is a chronic zoonotic disease caused by the larval form of Echinococcus multilocularis. In humans, it may become a serious chronic infection of the liver which resembles a slow malignant process leading to death when untreated. The aim of the study was an assessment of the risk factors of the E. multilocularis infections and the description of AE clinical course in the group of 36 patients with confirmed AE, hospitalized at the Department and Clinic of Tropical and Parasitic Diseases, Poznan University of Medical Sciences between 2013 and 2022. Among the study participants, most patients cultivated land, bred livestock, worked in the forest, or were employed in animal shelters. The E. multilocularis infection was diagnosed based on imaging and immunoassay techniques within 6 months in the majority of patients hospitalized in the Department. All patients hospitalized in the Department initiated anti-parasitic therapy at the moment of the diagnosis. Pharmacological treatment combined with surgery was applied in most of the study participants, who were presented with more advanced stages of infection. We conclude the following: 1. For humans in the risk group, regular abdominal imaging examinations and the detection of specific antibodies against E. multilocularis are recommended. 2. Regular screening tests in the hyperendemic areas of AE would increase the early detection of the disease and to improve the clinical prognosis in this extremely life-threatening parasitic disease.

Feasibility analysis and study of an intrahepatic portal vein infection hepatic alveolar echinococcosis C57 mouse model

Objective

The aim of the study was to establish and study an intrahepatic portal vein infection hepatic alveolar echinococcosis (HAE) C57 mouse model and provide a theoretical basis for clinical research on HAE.

Methods

C57 mice were used to establish the HAE mouse model. The location, size, morphology, appearance, and pathological changes in liver lesions in different groups of mice were characterized using ultrasound, magnetic resonance imaging (MRI), and haematoxylin and eosin staining.

Results

The mortality rate of the C57 mice was 20%, and the success rate of infection was 75%. The abdominal ultrasound images and MRIs clearly indicated the location, size, shape, and appearance of the liver lesions and the relationship between the lesions and the adjacent organs. The size, morphology, and signal of the livers in the control group were normal. The pathological results of the experimental group indicated a hepatic vesicular acinar cyst, while those of the control group exhibited normal livers.

Conclusion

The intrahepatic portal vein infection HAE mouse model was successfully established.

Serological Assays for Alveolar and Cystic Echinococcosis—A Comparative Multi-Test Study in Switzerland and Kyrgyzstan

Both alveolar (AE) and cystic echinococcosis (CE) are lacking pathognomonic clinical signs; consequently imaging technologies and serology remain the main pillars for diagnosis. The present study included 100 confirmed treatment-naïve AE and 64 CE patients that were diagnosed in Switzerland or Kyrgyzstan. Overall, 10 native Echinococcus spp. antigens, 3 recombinant antigens, and 4 commercial assays were comparatively evaluated. All native E. multilocularis antigens were produced in duplicates with a European and a Kyrgyz isolate and showed identical test values for the diagnosis of AE and CE. Native antigens and three commercial tests showed high diagnostic sensitivities (Se: 86–96%) and specificities (Sp: 96–99%) for the diagnosis of AE and CE in Swiss patients. In Kyrgyz patients, values of sensitivities and specificities were 10–20% lower as compared to the Swiss patients’ findings. For the sero-diagnosis of AE in Kyrgyzstan, a test-combination of an E. multilocularis protoscolex antigen and the recombinant antigen Em95 appears to be the most suitable test strategy (Se: 98%, Sp: 87%). For the diagnosis of CE in both countries, test performances were hampered by major cross-reactions with AE patients and other parasitic diseases as well as by limited diagnostic sensitivities (93% in Switzerland and 76% in Kyrgyzstan, respectively).

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.