Verminous pneumonia in European hedgehogs (Erinaceus europaeus).

The European hedgehog (Erinaceus europaeus) is a common wildlife species in European countries. Populations are declining due to anthropogenic factors and natural diseases. Verminous pneumonia has been observed as a frequent infectious disease in hedgehogs submitted for diagnostic postmortem examination. This prompted the present in-depth investigation on the lungs of 27 necropsied hedgehogs with confirmed lungworm infections, with or without antiparasitic treatment prior to death. The histological and/or parasitic (fecal samples) examination identified Capillaria aerophila infection in most animals (82%). The parasites were found free in the airway lumen and/or within the airway epithelium, from the larynx to bronchioles. Embedded worms and eggs were associated with epithelial hyperplasia or metaplasia, and long-term inflammation. More than half of the animals (59%) carried Crenosoma striatum, and 41% had a coinfection. C striatum adults were predominantly found free in the lumen of bronchi and bronchioles, and larvae were occasionally seen in granulomas in the pulmonary interstitium, the liver, and the intestine. Independent of the parasite species, a lymphoplasmacytic peribronchitis and, less frequently, interstitial infiltration of eosinophils, neutrophils, and macrophages as well as pneumocyte type II hyperplasia was seen. Interestingly, the extent of pneumonia was not correlated with age, respiratory clinical signs, antiparasitic treatment, or single or coinfection. Verminous pneumonia appeared to be the cause of death in over 25% of the animals, indicating that these parasites not only coexist with hedgehogs but can also be a primary pathogen in this species.

Intense Focus of Alveolar Echinococcosis, South Kyrgyzstan.

Human alveolar echinococcosis (AE) is a highly pathogenic zoonotic parasitic disease caused by Echinococcus multilocularis. An ultrasound study in southern Kyrgyzstan during 2012 revealed a prevalence of 4.2% probable or confirmed AE and an additional 2.2% possible AE, representing an emerging situation. The risk for probable or confirmed AE was significantly higher in dog owners.

TRANSMISSION OF PTERYGODERMATITES NYCTICEBI IN A COLONY OF GOELDI'S MONKEYS ( CALLIMICO GOELDII) AND EVALUATION OF TREATMENT AND CONTROL.

Over a 2-yr period, four Goeldi's monkeys ( Callimico goeldii) died in a private zoo due to infections with the spirurid nematode Pterygodermatites nycticebi. Therapeutic measures with different anthelmintics were not successful. Due to the severe consequences caused by these infections, different actions were initiated, including sanitation measures and controlling of potential intermediate hosts (coprophagous arthropods). To identify possible intermediate hosts, arthropod species detected in the enclosure-parasite-free German cockroaches ( Blattella germanica), European earwigs ( Forficula auricularia), and rough woodlice ( Porcellio scaber)-were experimentally fed with feces of monkeys with patent P. nycticebi infections, resulting in established infections with third-stage larvae (L3) in roaches and earwigs. Furthermore, spiruroid L3 were detectable in 43% of the roaches and 30% of earwigs caught at the zoo. Polymerase chain reaction and sequence analysis of eggs, larval, and adult stages resulted in identical results, confirming the establishment of the parasite's life cycle in the zoo. This is the first documentation of the vector capacity of the European earwigs for P. nycticebi. As a measure of sanitation, a large part of the enclosure was emptied and cleaned. The Goeldi's monkeys were quarantined and treated with levamisole (7.5 mg/kg sc twice in intervals of 2 wk). Repeated coprologic examinations by zinc chloride flotation were undertaken. After the levamisole therapy, eggs were not found in the feces for 3 mo. However, shortly after resettling the monkeys into the sanitized enclosure, reshedding of small amounts of spirurid eggs was observed, whereupon deworming with levamisole was prescribed several times per year. The sanitation measures and the elimination of the intermediate hosts in a natural enclosure are presented as an example of the long-term controlling of the parasites.

Comparison of Leishmania typing results obtained from 16 European clinical laboratories in 2014.

Leishmaniasis is endemic in southern Europe, and in other European countries cases are diagnosed in travellers who have visited affected areas both within the continent and beyond. Prompt and accurate diagnosis poses a challenge in clinical practice in Europe. Different methods exist for identification of the infecting Leishmania species. Sixteen clinical laboratories in 10 European countries, plus Israel and Turkey, conducted a study to assess their genotyping performance. DNA from 21 promastigote cultures of 13 species was analysed blindly by the routinely used typing method. Five different molecular targets were used, which were analysed with PCR-based methods. Different levels of identification were achieved, and either the Leishmania subgenus, species complex, or actual species were reported. The overall error rate of strains placed in the wrong complex or species was 8.5%. Various reasons for incorrect typing were identified. The study shows there is considerable room for improvement and standardisation of Leishmania typing. The use of well validated standard operating procedures is recommended, covering testing, interpretation, and reporting guidelines. Application of the internal transcribed spacer 1 of the rDNA array should be restricted to Old World samples, while the heat-shock protein 70 gene and the mini-exon can be applied globally.

First Case of Human Cerebral Taenia martis Cysticercosis.

Taenia martis is a tapeworm affecting mustelids, with rodents serving as intermediate hosts. The larval stage (cysticercus) has been found before only rarely in humans or primates. We hereby describe a case of cerebral T. martis cysticercosis in a French immunocompetent patient, confirmed by DNA analyses of biopsy material.

Clinical and molecular investigation of a canine distemper outbreak and vector-borne infections in a group of rescue dogs imported from Hungary to Switzerland.

BACKGROUND: Canine distemper virus (CDV) is a major pathogen of dogs and wild carnivores worldwide. In Switzerland, distemper in domestic dogs is rarely reported. In recent years, the import of dogs from Eastern Europe to Switzerland has steadily increased. In the present study, we describe a distemper outbreak in 15 rescue dogs that were imported from Hungary to Switzerland by an animal welfare organisation. The data on vaccination and medical history were recorded (14 dogs), and the samples were collected to investigate CDV and vector-borne infections (13 dogs) and canine parvovirus infection (12 dogs). The dogs were monitored for six months. RESULTS: One dog was euthanised directly after import. Thirteen dogs showed clinical signs after arrival, i.e., diarrhoea (57 %), coughing (43 %) and nasal and/or ocular discharge (21 %); radiographic findings that were compatible with bronchopneumonia were present in four dogs. CDV infection was diagnosed in 11 dogs (85 %); 10 dogs (91 %) tested PCR-positive in conjunctival swabs. Vector-borne infections (Babesia spp., Leishmania infantum, Dirofilaria immitis) were found in 4 dogs (31 %). Three dogs were hospitalized, and six dogs received ambulatory therapy for up to two months until recovery. None of the dogs developed neurological disease. CDV shedding was detected for a period of up to four months. Because dogs were put under strict quarantine until CDV shedding ceased, CDV did not spread to any other dogs. The CDV isolates showed 99 % sequence identity in the HA gene among each other and belonged to the Arctic-like lineage of CDV. CONCLUSIONS: The present study highlights the imminent risks of spreading contagious viral and vector-borne infections through the non-selective import of sick dogs and dogs with incomplete vaccination from Eastern Europe. CDV shedding was detected for several months after the cessation of clinical signs, which emphasised the roles of asymptomatic carriers in CDV epidemiology. A long-term follow-up using sensitive PCR and strict quarantine measures is of upmost importance in preventing the spread of infection. Dog owners and animal welfare organisations should be educated regarding the importance of complete vaccinations and the impact of dog imports on the spread of viral and vector-borne pathogens.

Nematode dermatitis due to Angiostrongylus vasorum infection in a dog.

BACKGROUND: Angiostrongylus vasorum is a nematode that primarily infects Canidae. The adult parasites are found in the pulmonary arterial circulation and the right side of the heart. The most common clinical sign is respiratory dysfunction. Bleeding, neurological, ocular, cardiovascular and gastrointestinal disorders are also reported. Skin lesions are very unusual. HYPOTHESIS/OBJECTIVES: This report describes a nematode dermatitis due to A. vasorum infection. To the best of the authors' knowledge, this is the first case of a dog infected with this parasite that initially presented with skin lesions only. ANIMAL: A 3-year-old female Weimaraner dog presented with a crusted papular dermatitis on the bridge of the nose and on the pinnae, and an erythematous pododermatitis with erosions and perionyxis of one digit of 1 week's duration. Two weeks later the dog developed respiratory distress. METHODS AND RESULTS: Skin scrapings and fungal culture were negative for parasites and dermatophytes. Histopathological examination showed dermal granulomas and pyogranulomas with eosinophils centred around parasitic elements compatible with nematode larvae. Angiostrongylus vasorum DNA was demonstrated in skin biopsies. Chest radiographs were compatible with verminous pneumonia and a Baermann test revealed A. vasorum larvae. The dog was treated orally with fenbendazole, with rapid improvement and complete cure after 3 months. CONCLUSIONS AND CLINICAL IMPORTANCE: Angiostrongylus vasorum should be considered in dogs presented with skin lesions and respiratory signs. Skin biopsy, chest radiographs and Baermann test should be included in the diagnostic investigation.

Assessing PCR-Positive Acanthamoeba Keratitis-A Retrospective Chart Review.

Ophthalmologists' diagnostic and treatment competence in Acanthamoeba keratitis varies widely. This investigator-initiated, retrospective, single-center chart review examined the electronic patient files regarding PCR-positive Acanthamoeba keratitis. We included corneal and contact lens assessments. We further reviewed the patient's medical history, corneal scraping results regarding viral or fungal co-infections, and the duration from symptom onset to final diagnosis. We identified 59 eyes of 52 patients from February 2010 to February 2023, with 31 of 52 (59.6%) being female patients. The median (IQR, range) patient age was 33 (25.3 to 45.5 [13 to 90]) years, and the mean (SD, range) time to diagnosis after symptom onset was 18 (10.5 to 35 [3 to 70]) days. Overall, 7 of 52 (7.7%) patients displayed a bilateral Acanthamoeba infection, and 48 (92.3%) used contact lenses at symptom onset. Regarding other microbiological co-infections, we found virologic PCR testing in 45 of 52 (86.5%) patients, with 3 (6.7%) positive corneal scrapings. Fungal cultures were performed in 49 of 52 (94.2%) patients, with 5 (10.2%) positive corneal scrapings. The medical treatment success rate was 45/46 (97.8%). This study raises awareness of patient education in contact lens handling and screens for further microbial co-infections in suspected Acanthamoeba cases.

Unusual presentation of alveolar echinococcosis as prostatic and paraprostatic cysts in a dog.

BACKGROUND: Alveolar echinococcosis (AE) is caused by the larval stage (metacestode) of Echinococcus multilocularis. The domestic dog can act as a definitive host and harbor adult cestodes in its small intestine or become an aberrant intermediate host carrying larval stages that may cause severe lesions in the liver, lungs and other organs with clinical signs similar to AE in humans. CASE PRESENTATION: A case of canine AE, affecting the liver and prostate with development of multilocular hydatid paraprostatic cysts and possible lung involvement is described in an 8-year-old neutered male Labrador retriever dog.The dog presented with progressive weight loss, acute constipation, stranguria and a suspected soft tissue mass in the sublumbar region. Further evaluation included computed tomography of the thorax and abdomen, which revealed cystic changes in the prostate, a paraprostatic cyst, as well as lesions in the liver and lungs. Cytological examination of fine-needle aspirates of the liver, prostate and paraprostatic cyst revealed parasitic hyaline membranes typical of an Echinococcus infection and the presence of E. multilocularis-DNA was confirmed by PCR. The dog was treated with albendazole and debulking surgery was considered in case there was a good response to antiparasitic treatment. Constipation and stranguria resolved completely. Six months after the definitive diagnosis, the dog was euthanized due to treatment-resistant ascites and acute anorexia and lethargy. CONCLUSIONS: To the authors' knowledge, this is the first publication of an E. multilocularis infection in a dog causing prostatic and paraprostatic cysts. Although rare, E. multilocularis infection should be considered as an extended differential diagnosis in dogs presenting with prostatic and paraprostatic disease, especially in areas where E. multilocularis is endemic.

A Muskrat (Ondatra zibethicus) with alveolar echinococcosis bitten to death by a dog - a challenge for the forensic pathologist as an expert witness.

We present a case that illustrates the complex contexts in which forensic veterinary pathology examinations may be carried out. A wild muskrat (Ondatra zibethicus) had died after a putative bite attack from a domestic dog. Bite attacks by privately owned dogs on wild animals in Switzerland violate the Swiss civil (and/or hunting) laws, and dog owners are generally punished with a monetary fine; hence, this case appeared to be straightforward. However, the results of the subsequent post-mortem examination of the muskrat not only confirmed the presence of injuries related to the bite attack, but also detected alveolar echinococcosis (ie, infestation with Echinococcus multilocularis). Therefore, as an intermediate host of the parasite, the muskrat could have contributed to further spread of a severe helminthic zoonosis had it not been killed by the dog. It was probably an easy prey for the dog as it probably had been weakened by the disease. Furthermore, muskrats are considered as pests and invasive species, and are non-indigenous huntable game in Switzerland and other European countries in which programmes for the prevention of their further spread and endangerment of native wildlife are established. The role of the forensic veterinary pathologist in such a complex scenario is to adopt an unbiased approach and establish the facts, which in this case was to determine the cause of death and suspected perpetrator, identify any concomitant and/or underlying diseases and consider potential animal welfare issues.

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.

Immortalization and transformation of primary cells mediated by engineered ecDNAs.

Focal gene amplifications are among the most common cancer-associated mutations, but their evolution and contribution to tumorigenesis have proven challenging to recapitulate in primary cells and model organisms. Here we describe a general approach to engineer large (>1 Mbp) focal amplifications mediated by extrachromosomal circular DNAs (ecDNAs, also known as "double minutes") in a spatiotemporally controlled manner in cancer cell lines and in primary cells derived from genetically engineered mice. With this strategy, ecDNA formation can be coupled with expression of fluorescent reporters or other selectable markers to enable the identification and tracking of ecDNA-containing cells. We demonstrate the feasibility of this approach by engineering MDM2-containing ecDNAs in near-diploid human cells, showing that GFP expression can be used to track ecDNA dynamics under physiological conditions or in the presence of specific selective pressures. We also apply this approach to generate mice harboring inducible Myc - and Mdm2 -containing ecDNAs analogous to those spontaneously occurring in human cancers. We show that the engineered ecDNAs rapidly accumulate in primary cells derived from these animals, promoting proliferation, immortalization, and transformation.

Xenosurveillance proof-of-principle: Detection of Toxoplasma gondii and SARS-CoV-2 antibodies in mosquito blood meals by (pan)-specific ELISAs.

Blood-fed insects can be used to analyse the host blood for circulating vertebrate pathogens or antibodies directed against them. We tested whether naturally acquired antibodies in different host species can be detected by host-specific and pan-specific ELISAs in mosquito blood meals. Cat- and alpaca-specific ELISAs could detect antibodies against Toxoplasma gondii or SARS-CoV-2 in blood meals of Aedes japonicus for 48 and at least 24 h, respectively. In the pan-specific ELISA, a conjugated protein A/G and anti-IgY were used to detect antibodies of mammalian and bird hosts. Thus, Toxoplasma antibodies could be detected in mosquitoes fed on blood from humans, chicken, pig, and sheep up to 72 h after the blood meal. The results, however, demonstrated differences in sensitivities between different host species, and the assay requires further evaluation. Xenosurveillance with antibody detection in mosquito blood meals can be an additional surveillance tool that would especially be helpful when it is difficult to sample the potential animal reservoirs.

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.

Evaluation of a structured treatment discontinuation in patients with inoperable alveolar echinococcosis on long-term benzimidazole therapy: A retrospective cohort study.

OBJECTIVES: Alveolar echinococcosis (AE) is an orphan zoonosis of increasing concern in endemic areas, including Europe. It frequently presents in an advanced, inoperable stage, that requires life-long parasitostatic benzimidazole therapy. In some patients, long-term therapy leads to negative anti-Em18 antibody ELISA and PET. It is disputed, whether these patients are truly cured and treatment can be safely discontinued. Our aim was to retrospectively assess long-term outcome of 34 patients with inoperable AE who participated in a previous study to determine feasibility of benzimidazole treatment cessation. METHODS: Retrospective analysis of medical charts was undertaken in all 34 AE patients who participated in our previous study. Of particular interest were AE recurrence or other reasons for re-treatment in patients who stopped benzimidazole therapy and whether baseline clinical and laboratory parameters help identify of patients that might qualifiy for treatment cessation. Additionally, volumetric measurement of AE lesions on contrast-enhanced cross-sectional imaging was performed at baseline and last follow-up in order to quantify treatment response. RESULTS: 12 of 34 patients stopped benzimidazole therapy for a median of 131 months. 11 of these patients showed stable or regressive AE lesions as determined by volumetric measurement. One patient developed progressive lesions with persistently negative anti-Em18 antibody ELISA but slight FDG-uptake in repeated PET imaging. At baseline, patients who met criteria for treatment cessation demonstrated higher lymphocyte count and lower total IgE. CONCLUSION: Treatment cessation is feasible in inoperable AE patients, who demonstrate negative anti-Em18 antibody ELISA and PET on follow-up. Close monitoring including sectional imaging is strongly advised.

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).

Self-assembly of supramolecular architectures and polymers by orthogonal metal complexation and hydrogen-bonding motifs.

A modular construction kit with two orthogonal noncovalent binding sites for self-assembly of supramolecular architectures is presented. The heteroditopic building blocks contain a terpyridine (tpy) unit for coordination of metal ions and a Hamilton receptor for multiple H-bonding of cyanuric acid derivatives. The association constants of ligand binding of M(II) complexes (M=Ru, Zn, Fe, and Pt) with a dendritic end cap were determined to be in the range of 10(2) and 10(4) L mol(-1) in chloroform. The capabilities for binding of metal ions were investigated by (1)H NMR and UV/Vis spectroscopy. The Fe complexes are most appropriate for the generation of discrete and high-ordered architectures due to their strong tendency to form FeL(2) complexes. Superstructures are readily formed in a one-pot procedure at room temperature. No mutual interactions between the orthogonal binding motifs were observed, and this demonstrates the highly specific nature of each binding process. Decomplexation experiments were carried out to examine the reversibility of Fe-tpy coordination. Substitution of the terminal end cap with a homoditopic bis-cyanurate linkage leads to formation of an iron-containing supramolecular strand. Formation of coordination polymers was confirmed by viscosity measurements. The supramolecular polymer strands can be reversibly cleaved by addition of a terminating cyanuric acid building block, and this proves the dynamic nature of this noncovalent polymerization process.

Alternatives to robenidine to control gastrointestinal disorders of weaner rabbits in the field.

Gastrointestinal disorders due to Eimeria sp. and E. coli overgrowth cause high mortality in weaner rabbits and the interest in alternatives to coccidiostats is high. This study aimed to investigate the superiority of natural feed additives towards robenidine preserving gastrointestinal health in the field. Rabbits were divided into four groups, Control Group (CG) exclusively supplemented with robenidine, Sainfoin Group (SG) was supplemented with a combination of robenidine and sainfoin, and two additional groups were respectively supplemented with Herb-All COCC-X (garlic; conessi tree) (HG: Herbal Group) and by a combination of Herb-All COCC-X and Klinofeed (clinoptilolite) (MG: Mineral Group). Eimeria sp. (98,40%) and E. coli overgrowth (73.60%) could be confirmed as the main causes for losses. High mortality rates (SG: 30.00% - MG: 47.50%), also in the groups receiving robenidine (SG: 30.00%; CG: 45.00%), reinforced the importance of alternatives in the field. The natural additives of groups SG, HG and MG did not have a significant influence on the weight gains and the oocyst counts in the jejunum/ileum and caecum of slaughter rabbits at the end of the trial, compared to group CG. Significantly higher oocyst shedding in SG (p = 1.4E-03) and HG (p = 1.4E-05) during the trial may be explained by a higher surviving rate of diseased rabbits in those groups, fostered by beneficial effects of the additives, which should be investigated further.

PET/CT helps to determine treatment duration in patients with resected as well as inoperable alveolar echinococcosis.

PURPOSE: The aim of the study was to determine the role of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) at the end of benzimidazole therapy in alveolar echinococcosis. METHODS: A total of 22 patients undergoing PET/CT at the end of benzimidazole therapy were retrospectively registered. Maximum standardized uptake values (SUVmax) were measured in remaining echinococcus manifestations and compared to normal liver tissue. Long-term clinical follow-up was performed, and recorded data included laboratory parameters, clinical information and imaging. RESULTS: All patients had no detectable levels of Em-18 antibodies and all echinococcus manifestations were negative on PET/CT, i.e. without focally increased FDG uptake or uptake higher than normal/non-infected liver tissue. All manifestations displayed significantly less FDG-uptake than normal liver tissue, i.e. SUVmax 1.8 (interquartile range (IQR) 1.5-3.5) vs. 3.0 (IQR 2.6-5.7), (p < 0.001). Patients were clinically followed for a median of 9.5 years (IQR 6.5-32.0 years) after their initial diagnosis and for 4.5 years (IQR 3.0-14.0 years) after discontinuation of benzimidazole therapy. No patient showed signs of recurrent infection at the last clinical visit. The 10-year and 20-year freedom from all-cause mortality was 95.0% (95% confidence interval 69.5% - 99.3%), for both. Two events occurred in 292 patient years of follow-up; i.e. two patients (9%) died, one because of pancreatic cancer, the other one because of unknown reasons with no detectable antibody levels. CONCLUSIONS: Negative FDG-PET/CT results combined with no detectable levels of Em-18 antibodies may allow for the safe discontinuation of benzimidazole therapy in patients with alveolar echinococcosis.

An immunocompetent farmer with isolated cerebral alveolar echinococcosis: illustrative case.

BACKGROUND: Alveolar echinococcosis is a rare condition, but living or working in a rural environment is a substantial risk factor. The liver is the organ primarily affected, with additional extrahepatic manifestations in approximately 25% of cases. Primary extrahepatic disease is rare, and isolated cerebral involvement is extremely unusual. OBSERVATIONS: The authors described an illustrative case of isolated cerebral alveolar echinococcosis in an immunocompetent farmer. Magnetic resonance imaging of the brain showed a predominantly cystic lesion with perifocal edema and a "bunch of grapes" appearance in the left frontal lobe. Histology revealed sharply demarcated fragments of a fibrous cyst wall accompanied by marked inflammation and necrosis. Higher magnification showed remnants of protoscolices with hooklets and calcified corpuscles. Immunohistochemistry and polymerase chain reaction (PCR) analysis confirmed the diagnosis of cerebral alveolar echinococcosis. Interestingly, serology and thoracic and abdominal computed tomography results were negative, indicative of an isolated primary extrahepatic manifestation. LESSONS: Isolated, primary central nervous system echinococcosis is extremely rare, with only isolated case reports. As in the authors' case, it can occur in immunocompetent patients, especially persons with a rural vocational history. Negative serology results do not exclude cerebral echinococcosis, which requires histological confirmation. Immunohistochemical staining and PCR analysis are especially useful in cases without classic morphological findings.