We report the 30-yr history of a well-documented human case of alveolar echinococcosis, with a lung lesion at presentation followed by the discovery of a liver lesion, both removed by surgery. Subsequently, within the 13 years following diagnosis, metastases were disclosed in eye, brain and skull, as well as additional lung lesions. This patient had no immune suppression, and did not have the genetic background known to predispose to severe alveolar echinococcosis; it may thus be hypothesized that iterative multi-organ involvement was mostly due to the poor adherence to benzimidazole treatment for the first decade after diagnosis. Conversely, after a new alveolar echinococcosis recurrence was found in the right lung in 1994, the patient accepted to take albendazole continuously at the right dosage. After serology became negative and a fluoro-deoxy-glucose-Positron Emission Tomography performed in 2005 showed a total regression of the lesions in all organs, albendazole treatment could be definitively withdrawn. In 2011, the fluoro-deoxy-glucose-Positron Emission Tomography showed a total absence of parasitic metabolic activity and the patient had no clinical symptoms related to alveolar echinococcosis. The history of this patient suggests that multi-organ involvement and alveolar echinococcosis recurrence over time may occur in non-immune suppressed patients despite an apparently “radical” surgery. Metastatic dissemination might be favored by a poor adherence to chemotherapy. Combined surgery and continuous administration of albendazole at high dosage may allow alveolar echinococcosis patients to survive more than 30 years after diagnosis despite multi-organ involvement.

For clinical epidemiology specialists, connecting the genetic diversity of Echinococcus multilocularis to sources of infection or particular sites has become somewhat of a holy grail. It is very difficult to trace the infection history of alveolar echinococcosis (AE) patients as there may be an incubation period of five to 15 years before reliable diagnosis. Moreover, the variability of parasitic manifestations in human patients raises the possibility of genetically different isolates of E. multilocularis having different levels of pathogenicity. Thus, the exposure of human patients to different strains or genotypes circulating in geographically different environments may lead to different disease outcomes. Molecular tools, such as the microsatellite marker EmsB, were required to investigate these aspects. This genetic marker was previously tested on a collection of 1211 European field samples predominantly of animal origin, referenced on a publicly available database. In this study, we investigated a panel of 66 metacestode samples (between 1981 and 2019) recovered surgically from 63 patients diagnosed with alveolar echinococcosis originating from four European countries (France, Switzerland, Germany, Belgium). In this study, we identified nine EmsB profiles, five of which were found in patients located in the same areas of France and Switzerland. One profile was detected on both sides of the French-Swiss border, whereas most patients from non-endemic regions clustered together in another profile. EmsB profiles appeared to remain stable over time because similar profiles were detected in patients who underwent surgery recently and patients who underwent surgery some time ago. This study sheds light on possible pathways of contamination in humans, including proximity contamination in some cases, and the dominant contamination profiles in Europe, particularly for extrahepatic lesions.

Drug-based treatment of alveolar echinococcosis (AE) with benzimidazoles is in most cases non-curative, thus has to be taken lifelong. Here, we report on a 56-year-old male AE patient who received standard benzimidazole treatment and biliary plastic stents, and additionally self-medicated himself with the Peruvian plant extract Maca (Lepidium meyenii). After 42 months, viable parasite tissue had disappeared. Based on this striking observation, the anti-echinococcal activity of Maca was investigated in vitro and in mice experimentally infected with Echinococcus multilocularis metacestodes. Albendazole (ABZ)-treated mice and mice treated with an ABZ+Maca combination exhibited a significantly reduced parasite burden compared to untreated or Maca-treated mice. As shown by a newly established UHPLC-MS/MS-based measurement of ABZ-metabolites, the presence of Maca during the treatment did not alter ABZ plasma levels. In vitro assays corroborated these findings, as exposure to Maca had no notable effect on E. multilocularis metacestodes, and in cultures of germinal layer cells, possibly unspecific, cytotoxic effects of Maca were observed. However, in the combined treatments, Maca inhibited the activity of ABZ in vitro. While Maca had no direct anti-parasitic activity, it induced in vitro proliferation of murine spleen cells, suggesting that immunomodulatory properties could have contributed to the curative effect seen in the patient.

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.

BACKGROUND: Alveolar echinococcosis is a rare but potentially severe parasitic disease caused by the larval stage of Echinococcus multilocularis, endemic in many countries in the northern hemisphere, including Switzerland. While the liver is most commonly affected, other organs can also be involved either by contiguity or haematogenous spread. To date, there is no epidemiological or clinical data on alveolar echinococcosis in the canton of Geneva. OBJECTIVES: To describe the demographic, epidemiological, clinical and therapeutic characteristics of alveolar echinococcosis in the canton of Geneva between 2010 and 2021. METHODS: An investigation was conducted among physicians from Geneva University Hospitals (HUG) and the private sector likely to encounter patients diagnosed with alveolar echinococcosis between 2010 and 2021. All patients being treated in the canton of Geneva were included. After obtaining their consent, an epidemiological questionnaire was completed by patients, and a clinical questionnaire by their referring physicians. Demographic, epidemiological and clinical data were entered into REDCap, then extracted and analysed. RESULTS: Of a total of 27 patients diagnosed with alveolar echinococcosis, 25 were included in the study; one patient did not provide his consent and one patient could not be contacted. The annual incidence of alveolar echinococcosis in the canton of Geneva was calculated at 0.24 cases per 100,000 inhabitants based on the subset (n = 14) domiciled in Geneva. The vast majority of patients (n = 24; 96%) were followed at HUG. The median age of patients was 55 years (range: 17–79) with a slight predominance of women (56%). Reported risk factors for alveolar echinococcosis included owning a vegetable garden (70.8%), often unfenced, practicing composting (69.6%), and owning a dog (58.3%) or a cat (58.3%). Four patients (16%) had an immunosuppressive condition. Only 52% of patients were symptomatic at the time of diagnosis. The liver was affected in most cases (n = 24; 96%), but one patient had a primary splenic location. Surgical resection for curative purposes was performed in 13 patients (52%). All patients received parasitostatic treatment with albendazole, discontinued in 5 patients (20%) due to drug-induced hepatitis. Three patients died (12%), of which two directly related to alveolar echinococcosis. CONCLUSION: Alveolar echinococcosis, a rare but severe disease, is endemic in the canton of Geneva. The establishment of mandatory reporting of this disease in Switzerland would allow monitoring of its epidemiological evolution. Primary and secondary prevention measures, currently non-existent, could potentially lower the incidence and severity of the disease.