Risk factors for alveolar echinococcosis in humans

Alveolar Echinococcosis: Is Non-Radical Liver Resection a Game Changer in the Current Treatment Approach to Patients with Advanced Alveolar Echinococcosis Disease? Single Center Experience of Poland

BACKGROUND

Alveolar echinococcosis is parasitic disease caused by Echinococcus multilocularis and spread endemically in the northern hemisphere. Although alveolar echinococcosis is considered a rare disease, with approximately 18,000 new cases diagnosed annually, it continues to present significant diagnostic and therapeutic challenges. Alveolar echinococcosis affects the liver through slow, asymptomatic infiltration over many years. At the time of diagnosis, approximately 70% of cases are not eligible for radical lesion resection. The aim of the study was to evaluate whether non-radical surgery increases patients' survival rates.

METHODS

We conducted a prospective analysis on patients diagnosed with alveolar echinococcosis in years 1995-2017 who underwent liver resection. Age, gender, mass of lesion, extensive nature of the operation (radical vs. conservative) and surgical procedures were collected. Mortality was analyzed.

RESULTS

Mean resected lesions' weight was statistically higher in non-radically resected group 1396,00 g (SD ± 845,39) compared with radically resected group 549,43 g (SD ± 364,27), p = 0,004. The type of surgical treatment did not significantly affect patient survival.

CONCLUSION

The complete lesion resection (in combination with albendazole) is only a curative therapy, if feasible. In advance stages when radical resection is not feasible, the reductive or debulking surgery should be done for symptoms' alleviation and quality of life improvement.

Spinal Echinococcosis in a Japanese Woman Living in Tokyo: Diagnostic Challenges in Non-endemic Areas and Public Health Implications

Echinococcosis, caused by Echinococcus spp., often affects the lungs and liver, and spinal involvement is rare. Echinococcus multilocularis is prevalent in Japan, particularly in Hokkaido. We herein report a rare case of spinal echinococcosis in a 31-year-old woman who was diagnosed in Tokyo. Spinal echinococcosis is uncommon and often leads to misdiagnoses. The patient likely contracted the disease via contaminated fresh produce transported from an endemic region. This study emphasizes the diagnostic challenges of spinal echinococcosis in non-endemic regions and highlights the public health concerns related to the spread of infections in non-endemic areas.

Retrospective multidisciplinary analysis of human alveolar echinococcosis in Hungary using spatial epidemiology approaches

Human alveolar echinococcosis (HAE), which is caused by the larval stage of the Echinococcus multilocularis tapeworm, is an increasing healthcare issue in Hungary. Among the 40 known cases in the country, 25 were detected in the last five years. Our study aimed to reveal the geographically underlying risk factors associated potentially with these cases. We investigated the spatial pattern and the impact of potential risk factors of HAE by cluster analysis, and local and global regression models. Also, a questionnaire survey on the patients' lifestyle was implemented. We found two HAE hyperendemic foci in the country with very dissimilar biotic and climatic features, and controversial impact of different environmental factors. Four factors, viz. forest cover (β = 0.291, p < 0.0001), surface soil wetness (β = - 0.157, p = 0.033), fox infection rate (β = 0.369, p < 0.0001) and socio-economic development (β = - 0.216, p = 0.009), proved important countrywide. The most forested and the least developed districts showed the highest HAE risk. Among the patients, kitchen gardening (67.86%) and dog ownership (67.86%) seemed the riskiest activities. Our models detected an anomaly in one of the poorest regions of Hungary where all risk factors behaved contrary to that of the neighboring areas. This phenomenon was supposed to be the result of under-detection of the disease, and it called attention to the urgent priority of knowledge dissemination to the public and the healthcare professionals.

Challenges and pitfalls in managing lumbosacral hydatid disease: Lessons learned from clinical practice

OBJECTIVE

Lumbosacral hydatid disease (LHD), a rare skeletal parasitic disease that involves the lumbosacral region. In this study, we summarized the diagnostic and therapeutic procedures for patients with LHD to provide insights into managing this rare disease.

METHODS

Between 2000 and 2023, 16 patients diagnosed with LHD were retrospectively analyzed. Each patient's medical records and follow-up details, were carefully assessed. The average follow-up period was 11.25 ± 6.41 years, providing valuable insights into treatment durability and effectiveness.

RESULTS

The diagnosis was confirmed via imaging, serological tests, and pathological examination. The clinical symptoms included lumbago with lower limb numbness (25 %) and urinary and fecal incontinence (25 %). All patients underwent surgery, with an average of 2.6 surgeries per patient. Thirteen (81.25 %) patients experienced recurrence postoperatively.

CONCLUSION

LHD is a severe and complex skeletal parasitic disease with significant diagnostic and therapeutic challenges. Effective management requires a comprehensive strategy involving surgery and additional therapies.

Case report: Echinococcus multilocularis infection in a dog showing gastrointestinal signs in Hokkaido, Japan

Echinococcus multilocularis is a cestode that causes human alveolar echinococcosis, a lethal zoonotic disease distributed in the northern hemisphere. The life cycle of this parasite is maintained in nature by voles as intermediate hosts and foxes as definitive hosts in Hokkaido, Japan. Although dogs are also susceptible to the parasite, the infection has been considered typically asymptomatic. We report the detection of E. multilocularis eggs in the diarrheal feces of a dog with chronic gastrointestinal signs, which disappeared after anthelmintic treatment. The mitochondrial genome sequence constructed by sequencing of the overlapping PCRs using DNA from the eggs was identical to the most predominant haplotype previously reported in red foxes in Hokkaido. This case highlights that Echinococcus infection should be considered as a differential diagnosis for diarrheal dogs in the disease endemic areas. Further efforts are needed to accumulate parasite genotypes in domestic dogs as well as humans to assess the risk of human infection from dogs.

What is the role of Swiss domestic cats in environmental contamination with Echinococcus multilocularis eggs?

BACKGROUND

The role of the domestic cat as definitive host for Echinococcus multilocularis and thus in environmental contamination with eggs has not yet been entirely resolved. This study aimed to assess the prevalence of E. multilocularis and other gastrointestinal parasites in Swiss domestic cats and to compare the diagnostic sensitivity of different methods for the detection of intestinal taeniid infection.

METHODS

Faecal samples from 146 cats were included in the study. Faecal samples only were available from 55 cats; for the other 91 cats, necropsy was performed in addition to faecal sample testing. All (n = 146) faecal samples were analysed by a combined sedimentation/flotation technique (44% ZnCl2) and by the sodium acetate-acetic acid-formalin (SAF) sedimentation technique; when sufficient material was available (n = 121 samples) the Baermann-Wetzel technique was also used. Additionally, all samples were analysed by two coproantigen (copro)-quantitative PCRs (qPCR): (i) a multiplex qPCR able to detect and differentiate between E. multilocularis, Echinococcus granulosus sensu lato and Taenia spp./other cestodes (CEST-qPCR) and (ii) an E. multilocularis-specific qPCR (EM-qPCR). Finally, the intestines were examined macroscopically and microscopically for parasite stages at necropsy (n = 91) and using an intestinal scraping technique (IST) (n = 64).

RESULTS

Of the 146 cats examined, 24 (17.1%) were infected by intestinal parasites, namely Hydatigera (syn. Taenia) taeniaeformis (8.9%), Toxocara cati (6.1%), Capillaria sp. (3.4%), hookworms (3.4%), Mesocestoides litteratus (1.4%), Giardia sp. (1.4%), Cystoisospora rivolta (1.4%), Cystoisospora felis (0.7%), Toxoplasma gondii (0.7%), Hammondia hammondi (0.7%) and Strongyloides sp. (0.7%). Necropsy and the IST revealed adult H. taeniaeformis in 12 animals, of which eight faecal samples were positive by the CEST-qPCR (sensitivity = 67%) and six samples by the sedimentation/flotation technique (sensitivity = 50%). No E. multilocularis infection was detected in the sampled cats. Using Bayesian latent class analysis, the mean posterior prevalence probability was 0.0% (95% confidence interval 0-0.83%) for E. multilocularis.

CONCLUSIONS

There was no evidence of E. multilocularis infection among the 146 cats examined, suggesting that the prevalence of this parasite is low (< 1%) in the Swiss domestic cat population. Nonetheless, some of the sampled cats were infected by parasites that have rodents as intermediate hosts, demonstrating successful predation by these cats, and some were infected with zoonotic parasites. Cats therefore should not be disregarded as potential hosts for E. multilocularis and other zoonotic parasites.

Chylothorax due to hepatic alveolar echinococcosis with infiltration of diaphragm and left pleura: a case report

BACKGROUND

Alveolar echinococcosis (AE) is an endemic parasitic zoonosis in Germany. In most cases, the liver is the primary organ affected.

CASE PRESENTATION

A 59-year old female patient presented with increasing exertional dyspnea and unintentional weight loss. A computed tomography (CT) scan showed a left-sided chylous pleural effusion and multiple intrahepatic masses with infiltration of the diaphragm and the pleura. The findings were initially misinterpreted as hepatocellular carcinoma (HCC) with infiltrating growth. Liver biopsy of one of the masses showed no evidence of malignancy, but an amorphous necrosis of unclear origin. HCC was further ruled out by magnetic resonance imaging (MRI). However, MRI findings were highly suspicious for hepatothoracic dissemination and complications due to AE. Typical histologic findings in a repeated and more specific examination of the liver tissue and a positive serology for echinococcosis confirmed the diagnosis of AE. As the hepatic and pulmonary manifestations were considered inoperable in a curative matter, an anti-parasitic treatment with albendazole was initiated. A video-assisted thoracoscopic surgery (VATS) with removal of the chylous effusion as well as a talc pleurodesis was performed to relieve the patient from dyspnea. Two months later, the patient was asymptomatic and a positron emission tomography (PET)-CT-scan with [18 F] fluoro-2-deoxy-d-glucose (FDG) showed a remarkable diminution of the hepatic manifestation.

CONCLUSIONS

This case demonstrates a rare presentation of alveolar echinococcosis with a focus on pulmonary symptoms, emphasizing the importance of evaluation for pulmonary involvement in patients with AE and respiratory symptoms.

Host spatiotemporal overlap in a park with high endemicity of Echinococcus multilocularis

Background

There has been a spate of recent cases of human alveolar echinococcosis (AE) in Alberta, Canada. Alveolar echinococcosis is caused by Echinococcus multilocularis, which is prevalent among coyote populations and present in domestic dogs in Alberta.

Methods and results

Using qPCR, we estimated the seasonal fecal prevalence of E. multilocularis in coyotes and dogs in a multiuse recreation area close to Edmonton, Alberta, where we also setup remote cameras to model seasonal changes in the overlap in temporal activity and the spatial intensity of use among coyotes, humans, and dogs, as a proxy of potential transmission. We detected E. multilocularis in 18 of 137 wild canid feces and none in 44 dog feces. After correcting for the qPCR test's sensitivity and specificity, we estimated at 15.7% (9.7-22.7%, 95% CrI) the true fecal prevalence for coyotes. Temporal overlap between coyotes and both humans and dogs increased in the fall and winter relative to the spring and summer. Coyote intensity of use showed seasonal variations and was higher on maintained trails and locations closer to visitor parking and at sites with high intensity of dog use.

Conclusions

Our results reinforce the need of an integrated approach, typical of both One-Health and Eco-Health, to park management for minimizing the likelihood of transmission where human and dog activity results in significant overlap with the one of the natural definitive hosts of zoonotic parasites.

Differentiation of hepatic alveolar echinococcosis with a hemangioma-like pattern compared to typical liver hemangioma using contrast-enhanced ultrasound: a pilot study

PURPOSE

Echinococcus multilocularis infects humans as a false intermediate host, primarily with intrahepatic manifestation. Incorrect diagnostic interpretation of these liver tumors, especially the hemangioma-like pattern, can lead to progressive disease. The aim of the study was to investigate the differentiation of typical hemangioma and a hemangioma-like pattern of E. multilocularis using contrast-enhanced ultrasound (CEUS).

METHODS

This prospective clinical pilot study comprised patients with hemangioma (n = 14) and patients with alveolar echinococcosis (AE) and hemangioma-like pattern (n = 7). Inclusion criteria were the detection of a liver lesion according to a hemangioma-like pattern on E. multilocularis Ulm classification-ultrasound (EMUC-US) and "confirmed" or "probable" AE according to WHO case definition. The comparison group had hepatic hemangioma with typical B-scan sonographic morphology. All participants underwent conventional and contrast-enhanced ultrasonography.

RESULTS

The patient group comprised five men (71.4%) and two women (28.6%) with a mean average age of 64.1 ± 11.2 years. The patient group with hemangioma comprised nine female subjects (64.3%) and five male subjects (35.7%) with a mean average age of 56.1 ± 12.0 years. Early arterial bulbous ring enhancement (p < 0.0001) and iris diaphragm phenomenon could only be visualized in the patients with hemangioma (p < 0.0001). Furthermore, the patients with hemangioma exhibited hyperenhancement in the late phase (p = 0.0003). In contrast, the patients exhibited typical early arterial rim enhancement (p < 0.0001) and, in the portal venous and late phase, complete or incomplete non-enhancement (black hole sign; p = 0.0004).

CONSLUSION

The behavior of hemangioma-like AE lesions and typical liver hemangiomas is significantly different on CEUS. AE should be considered as a possible differential diagnosis, especially in high-endemic areas.

Assessment of risk, landscape epidemiology and management strategies to combat alveolar echinococcosis in the rural communities of Hunza, Pakistan

BACKGROUND

Human alveolar echinococcosis (AE) is a neglected zoonotic disease. Prevalence of AE in humans is reported in Pakistan as a result of poor economic and sanitary conditions, close proximity to wildlife and limited knowledge of AE. Studies on the prevalence and transmission of AE have been limited, especially for rural Pakistan. The study objectives were to identify knowledge, attitudes and practices relating to AE, to determine awareness of the disease, and to identify knowledge about possible risk factors of infections involving the landscape epidemiological attributes of rural villages in Hunza, one of the districts of Gilgit-Baltistan, a region of Pakistan that borders China.

METHODS

A community-based cross-sectional study was conducted among the general population of Hunza to establish the level of awareness, knowledge, attitudes, practices, landscape epidemiology, and disease management and control relating to AE in rural areas of Hunza. Data were collected by questionnaire.

RESULTS

A total of 387 questionnaires was received. Statistical analysis showed that the population's knowledge about the disease was poor. The attitudes and practices of the participants indicated that their risk of infection was low. Knowledge of landscape epidemiology of the disease was poor but knowledge about AE disease management was good. The attitudes of residents toward disease treatment and control strategies were positive, although the overall knowledge of participants about prevention of infection was poor.

CONCLUSION

Knowledge of AE is poor among the residents of Hunza, Pakistan. Our study demands continued and strengthened awareness of the changes to lifestyle and practices associated with AE, not only in the study locality but throughout other areas of Pakistan.

Screening for Parasitic Infection and Tuberculosis in Immunosuppressed and Pre-Immunosuppressed Patients: An Observational Study

Reactivation of latent tuberculosis infection (LTBI) or latent parasitic infection (LPI) during drug-induced immunosuppression can have serious consequences. The Division of tropical and humanitarian medicine of the Geneva University Hospitals runs a specific consultation for parasitic screening of immunosuppressed or pre-immunosuppressed patients. We sought to determine the seroprevalence of LTBI and LPI in such patients and explore its relationship with country of origin or previous travel in a retrospective, single-centre observational study from 2016 to 2019. Demographic data, travel history, ongoing treatments and results of the parasitological (Strongyloides stercoralis, Trypanosoma cruzi, Echinococcus multilocularis, Entamoeba histolytica and Leishmania spp.) and TB screening were collected to calculate LPI or LTBI prevalence. Risk factors for LTBI and strongyloidiasis were analysed using Poisson regression with robust variance. Among 406 eligible patients, 24/353 (6.8%) had LTBI, 8/368 (2.2%) were positive for Strongyloides stercoralis infection, 1/32 (3.1%) was positive for Entamoeba histolytica and 1/299 (0.3%) was positive for Leishmaniasis. No cases of Trypanosoma cruzi (0/274) or Echinococcus multilocularis (0/56) infection were detected. Previous travel to or originating from high-prevalence countries was a risk factor for LTBI (PR = 3.4, CI 95%: 1.4–8.2 and 4.0, CI 95%: 1.8–8.9, respectively). The prevalence of serological Strongyloidiasis in immunosuppressed patients is lower in comparison to those without immunosuppression (PR = 0.1, CI 95%: 0.01–0.8). In conclusion, screening before immunosuppression needs to be individualized, and LTBI and LPI need to be ruled out in patients who originate from or have travelled to high-prevalence countries. The sensitivity of strongyloidiasis serology is reduced following immunosuppression, so an algorithm combining different tests or presumptive treatment should be considered.

Clinical Features, Radiological Characteristics, and Outcomes of Patients With Intracranial Alveolar Echinococcosis: A Case Series From Tibetan Areas of Sichuan Province, China

Objectives: Intracranial alveolar echinococcosis (IAE), a zoonotic disease, is a critical health problem in the Tibetan region. We aimed to describe the clinical and radiological characteristics and outcomes among patients with IAE.

Methods: We screened patients diagnosed with IAE between March 2015 and May 2019 at the Ganzi Tibetan Autonomous Prefecture People's Hospital. Detailed demographics, clinical characteristics, neuroimaging features, and outcomes were recorded.

Results: A total of 21 patients with an average age of 44.1 ± 12.7 years were included. Thirteen (61.9%) patients were male. The most common chief neurological complaint was headache (n = 17, 81.0%), followed by dizziness, seizure, visual disturbances, hemiparesis, disturbed consciousness, and dysphasia. All the patients had coexisting liver localizations. The typical neuroimaging features of IAE on cerebral magnetic resonance imaging scans showed obvious low-signal shadow with multiple small vesicles inside the lesions on T2-weighted images and FLAIR images. The pathological HE staining demonstrates vesicular lesions with several internal sacs. For hepatic alveolar echinococcosis (AE), the hepatic portal was invaded in six (28.6%) patients, and the portal vein (n = 5, 23.8%) was the mostly commonly involved vessel. As for treatment, 11 patients (52.4%) had poor compliance with albendazole. The duration of patients taken albendazole ranged from 2 months to 3 years. Cerebral AE surgery was performed in 11 patients, five of them underwent partial resection of AE lesions, and six patients received total resection. One patient with primary IAE underwent radical surgery. Ten patients (47.6%) died during the follow-up for a mean of 21.7 ± 11.9 (3–46) months. In total, 28.9% of the patients died within 5 years, and 71.6% died within 10 years. The median interval between the date of diagnosis as AE and death was 84 (19–144) months.

Conclusion: Despite substantial advances in diagnostic and therapeutic methods, the treatment of IAE remains difficult and results in unsatisfactory outcomes. The major critical issue is surgical treatment of IAE although the disease is disseminated. Besides, lifelong albendazole would be indicated, but most patients had poor medication compliance. It is important to educate patients about the necessity of medical treatment.

Species Detection within the Echinococcus granulosus sensu lato Complex by Novel Probe-Based Real-Time PCRs

Infections with eggs of Echinococcus granulosus sensu lato (s.l.) can cause cystic echinococcosis in intermediate host animals and humans. Upon ingestion of viable eggs, oncospheres hatch from the eggs and subsequently develop into fluid-filled larval cysts, most frequently in the liver or the lungs. The slowly growing cysts progressively interfere with organ function. The risk of infection is determined by the host range of the parasite, its pathogenicity and other epidemiologically relevant parameters, which differ significantly among the five species within the E. granulosus s.l. complex. It is therefore essential to diagnose the correct species within E. granulosus s.l. to help understand specific disease epidemiology and to facilitate effective implementation of control measures. For this purpose, simple, fast and cost-effective typing techniques are needed. We developed quantitative real-time polymerase chain reactions (qPCRs) to target polymorphic regions in the mitochondrial genome of E. granulosus s.l. In a single-step typing approach, we distinguished E. granulosus s.l. members in four epidemiologically relevant subgroups. These were E. granulosus sensu stricto, E. equinus, E. ortleppi and the E. canadensis cluster. The technique also allowed identification and differentiation of these species from other Echinococcus or Taenia taxa for samples isolated from cysts or faeces.

Parasites in the changing world - Ten timely examples from the Nordic-Baltic region

The world is changing, and parasites adapt. The Nordic-Baltic region in northern Europe - including the Nordic countries Denmark, Finland, Iceland, Norway and Sweden, and the Baltic States Estonia, Latvia and Lithuania - is facing new parasitological challenges due to changes in populations of parasites and their hosts and the spread of new parasites to the region due to climate change. Some changes can also be ascribed to increased awareness and detection. In this paper, we review and discuss a convenience selection of ten timely examples of recent observations that exemplify trends and challenges from different fields of parasitology, with particular focus on climate change and potential changes in epidemiology of pathogens in northern Europe. The examples illustrate how addressing parasitological challenges often requires both intersectoral and international collaboration, and how using both historical baseline data and modern methodologies are needed.

A Sensitive, One-Way Sequential Sieving Method to Isolate Helminths' Eggs and Protozoal Oocysts from Lettuce for Genetic Identification

Different helminths and protozoa are transmitted to humans by oral uptake of environmentally resistant parasite stages after hand-to-mouth contact or by contaminated food and water. The aim of this study was to develop and validate a method for the simultaneous detection of parasite stages from fresh produce (lettuce) by a one-way isolation test kit followed by genetic identification (PCR, sequencing). Three sentinel zoonotic agents (eggs of Toxocara canis, Echinococcus multilocularis and oocysts of Toxoplasma gondii) were used to investigate the practicability and sensitivity of the method. The detection limits (100% positive results) in the recovery experiments were four Toxocara eggs, two E. multilocularis eggs and 18 T. gondii oocysts (in 4/5 replicates). In a field study, helminth DNA was detected in 14 of 157 lettuce samples including Hydatigera taeniaeformis (Syn. Taenia taeniaeformis) (four samples), T. polyacantha (three), T. martis (one), E. multilocularis (two) and Toxocara cati (four). Toxoplasma gondii was detected in six of 100 samples. In vivo testing in mice resulted in metacestode growth in all animals injected with 40–60 E. multilocularis eggs, while infection rates were 20–40% with 2–20 eggs. The developed diagnostic strategy is highly sensitive for the isolation and genetic characterisation of a broad range of parasite stages from lettuce, whereas the sensitivity of the viability tests needs further improvement.

Source attribution of human echinococcosis: A systematic review and meta-analysis

BACKGROUND

A substantial proportion of echinococcosis transmission to humans via contamination of food has been assumed. However, the relative importance of food as a transmission vehicle has previously been estimated through expert opinion rather than empirical data.

OBJECTIVE

To find and evaluate empirical data that could be used to estimate the source attribution of echinococcosis, in particular the proportion that is transmitted through contaminated food.

METHODS

A systematic review was undertaken to identify reports on the risk factors for human cystic (CE) and alveolar (AE) echinococcosis. Data bases searched included PubMed, Scopus, Web of Knowledge, Cab Direct, Science Direct, Google Scholar, eLIBRARY.RU, CyberLeninka, CNKI and VIP. Search terms included Echinococc*, hydatid, epidemiology, logistic regression, risk factors, odds ratio, relative risk, risk factors. Reports, including grey literature where available, that had suitable data were selected and data were extracted. The main pathways of transmission were hypothesised to be contact with the definitive host, contaminated water, contaminated food and contaminated environment (other than food). For each study the attributable fraction for these potential sources of infection was calculated from the data presented. A meta-analysis was then undertaken to obtain pooled estimates for the relative contribution of these transmission pathways.

RESULTS

Data from 28 cross-sectional studies and 14 case-control studies were extracted. There was strong evidence for transmission by direct contact with dogs for both CE and AE. The estimated attributable fractions were 26.1% (CI 13.8%-39.6%) and 34.4% (CI 20.7% -48.2%) respectively. Transmission through contaminated water was estimated to be responsible for approximately 29.4% (CI 12.1%-51.7%) for CE and 24.8% (CI 10.6% to 42.6%) for AE. Contaminated food may be responsible for approximately 23.4% of CE cases (CI 2.1%-47.3%). Globally, there was insufficient evidence to conclude AE can be transmitted by food, although case control studies from low human incidence areas suggested that possibly 32.5% (CI 10.0%-53.2%) could be transmitted by food. There was also insufficient evidence that direct contact with foxes was a significant source of human disease. There were no suitable studies with a risk of environmental contact reported, but the residual attributable fraction thatwould likely include this pathway was approximately 21.1% for CE and 11.1% for AE.

CONCLUSIONS

The results support the hypothesis that dog contact and drinking contaminated water are major pathways of transmission of both CE and AE. For contaminated food, the results are less consistent, but suggest that it is an important transmission pathway and provide better evidence than expert elicitations as previously used.

Hepatic alveolar echinococcosis: Comparative computed tomography study between two Chinese and two European centres

The main endemic areas for alveolar echinococcosis (AE) are in Central Europe and Western China, and in >98% of cases, AE manifests in the liver. The aim of this work was to compare European and Chinese patient groups for number, size, and computed tomography (CT) appearance of hepatic AE lesions. A total of 200 CT scans of patients with hepatic AE were evaluated by four blinded, experienced radiologists from two European (Besancon, Ulm) and two Chinese centres (Xining, Urumqi). In addition to noting the number, size, and localisation of the lesions, the radiologists evaluated morphological appearance using the Echinococcus multilocularis Ulm Classification - CT scheme. Chinese patients were younger than European patients (36.8 ± 13.2 vs. 63.5 ± 17.7; p < 0.0001) and had significantly larger lesions (120.4 ± 50.8 vs. 70.9 ± 39.8; p < 0.0001). The morphological appearance of the lesions on CT differed significantly between the two groups (p < 0.05), as did the number of lesions (2.6 ± 3.9 in European centres versus 3.8 ± 5.0 in Chinese centres; p = 0.0062). Patient age and AE-related morphological manifestations differ between Europe and China, but the reasons for the differences are unknown.

Genotyping Echinococcus multilocularis in Human Alveolar Echinococcosis Patients: An EmsB Microsatellite Analysis

For clinical epidemiology specialists, connecting the genetic diversity of Echinococcusmultilocularis 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.

A new SYBR green real-time PCR assay for semi-quantitative detection of Echinococcus multilocularis and Echinococcus canadensis DNA on bilberries (Vaccinium myrtillus)

Berries and vegetables are potential transmission vehicles for eggs of pathogenic parasites, such as Echinococcus spp. We developed a SYBR Green based semi-quantitative real-time PCR (qPCR) method for detection of Echinococcus multilocularis and Echinococcus canadensis DNA from berry samples. A set of primers based on the mitochondrial NADH dehydrogenase subunit 1 (nad1) gene was designed and evaluated. To assess the efficacy of the assay, we spiked bilberries (Vaccinium myrtillus) with a known amount of E. multilocularis eggs. The detection limit for the assay using the NAD1_88 primer set was 4.37 × 10-5 ng/μl of E. multilocularis DNA. Under artificial contamination of berries, 50 E. multilocularis eggs were reliably detected in 250 g of bilberries. Analytical sensitivity of the assay was determined to be 100% with three eggs. As an application of the assay, 21 bilberry samples from Finnish market places and 21 bilberry samples from Estonia were examined. Previously described sieving and DNA extraction methods were used, and the samples were analyzed for E. multilocularis and E. canadensis DNA using semi-quantitative real-time PCR and a melting curve analysis of the amplified products. Echinococcus DNA was not detected in any of the commercial berry samples. This easy and fast method can be used for an efficient detection of E. multilocularis and E. canadensis in bilberries or other berries, and it is applicable also for fruits and vegetables.

[Diagnostics and management of intra-abdominal Echinococcus manifestation]

INTRODUCTION

Cystic and alveolar echinococcosis are two potentially life-threatening diseases caused by the helminthic parasites Echinococcus granulosus or Echinococcus multilocularis, respectively. In central Europe a marked increase in incidence of both forms of echinococcosis has recently been observed.

OBJECTIVE

There is widespread uncertainty with diagnostic and treatment algorithms due to the close genetic relationship of both parasites and the similar presentation; however, since the treatment and prognosis significantly differ between the two diseases, a correct diagnosis is essential. This review summarizes the similarities and differences in the diagnostics and surgical treatment of these two parasites.

RESULTS

The correct diagnosis is mainly based on patient history, radiological imaging and serological testing. In cystic echinococcosis cyst viability and stage determine whether treatment is medicinal, interventional, surgical or a watch and wait strategy. For alveolar echinococcosis surgical resection in combination with perioperative or adjuvant medicinal treatment is the gold standard and the only therapeutic option. As identification of the disease is often delayed due to the oligosymptomatic manifestation, complex resections are frequently necessary that need to be treated by a multidisciplinary team of experts.

CONCLUSION

Echinococcosis is still a neglected disease due to the rarity and thus should be referred to experts in a tertiary hospital to avoid mistreatment or overtreatment. Due to a timely surgical, infectiological and interventional treatment in an interdisciplinary work-up, the prognosis of echinococcosis has significantly improved in recent years.

Survey of echinococcoses in southeastern Qinghai Province, China, and serodiagnostic insights of recombinant Echinococcus granulosus antigen B isoforms

Background

Echinococcoses, caused by metacestodes of Echinococcus granulosus (cystic echinococcosis; CE) and E. multilocularis (alveolar echinococcosis; AE), represent major emerging parasitic diseases. These enzootic helminthiases invoke significant public health concerns and social burdens in endemic areas. The diseases are prevalent in the Qinghai-Tibetan Plateau, China, while community-based epidemiological studies have been scarcely reported. We surveyed echinococcosis patients in the southeastern Qinghai Province, China, to better understand the concurrent epidemiological situation in this area.

Methods

During July and August of 2013 and 2014, we screened echinococcosis patients at Yushu and Golog Prefectures, Qinghai Province, China, in a diagnostic campaign. A total of 2856 people (male:female ratio, 1:1.12; mean age, 34.6 years; age range, 6–88 years) were ultrasonographically examined for the presence of hepatic echinococcal cysts. We also collected serum samples from patients and analyzed antibody reactivity against recombinant forms of diverse E. granulosus antigen Bs (rEgAgB1-5) by enzyme-linked immunosorbent assay.

Results

We detected 134 patients whose imaging scans were compatible with CE (115 cases) and AE (20 patients). One patient might have been infected with both CE and AE. The overall incidence was 4.7% (CE, 4.0%; AE, 0.7%). A large proportion (67.5%) of CE patients was diagnosed at active and transitional CE1-CE3 stages in their late 30s. The AE cases were generally detected at advanced stage in patients at early 20s (60%). Analysis of the receiver operating characteristic curve and Youden’s index indicated that rEgAgB2 was the most promising biomarker, followed by rEgAgB3 and rEgAgB1. Overall, sensitivity and specificity of rEgAgB1-3 were 84.5–92.7% and 91.9–94.6%, respectively. rEgAgB4 and 5 showed low sensitivity with high cross-reactivity.

Conclusions

Our results strongly suggest that disability-adjusted life years related to echinococcoses in Qinghai-Tibetan areas might be more serious than previously considered. Control and prevention strategy against CE and AE are highly required in these areas. In addition to ultrasonography, serological tests might provide supportive data. However, serological data should be carefully interpreted for differential diagnosis, especially in areas where both CE and AE are co-endemic.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3569-6) contains supplementary material, which is available to authorized users.

Seroprevalence of cystic echinococcosis in a high-risk area (Al-Mafraq Governorate) in Jordan, using indirect hemagglutination test

Hydatid disease (HD) is a zoonotic disease of humans and animals which is caused by infection with the larval stages of the taeniid cestodes of the genus Echinococcus. HD is endemic in many countries of the Middle East, including Jordan. The seroprevalence rate of HD in areas of elevated risk in Jordan has not previously been investigated using indirect haemagglutination (IHA) testing. In the present study, 512 blood samples were collected from recruited outpatients from an internal medicine clinic in Al-Mafraq Governmental Hospital in Jordan. Each participant signed a consent form and completed a questionnaire. The presence of antibodies specific for E. granulosus antigens was detected using an IHA test. Statistical analysis was performed by SPSS software using the Chi-square test. In all, 4.1% of the study participants were seropositive for E. granulosus IgG antibodies. There was a significant correlation between unexplained weight loss among seropositive patients (P = 0.018). Seropositivity was significantly higher in patients who slaughtered sheep inside their houses (P = 0.023). HD seroprevalence did not correlate with gender (P = 0.433), age (P = 0.880), residency status (P = 0.938), or educational level (P = 0.808). The vast majority (75.2%) of participants reported no prior knowledge about HD, and 99.8% were not aware about the etiology of the disease.

Health-related quality of life in patients with alveolar echinococcosis: a cross-sectional study

PURPOSE

The Alveolar echinococcosis (AE) is a rare zoonosis caused by the parasite Echinococcus multilocularis. To date, nothing is known about the health-related quality of life (HRQoL) in patients with AE. The aim of the study was to evaluate the HRQoL in patients with AE in comparison of the healthy population.

METHODS

We used the 36-Item Short Form Health Survey (SF-36) questionnaire to evaluate the HRQoL. The SF-36 scales have a range of 0-100 (0 represents the worst and 100 the most favourable state of health). SAS Version 9.2 was used for the statistical analysis of AE-cases (n = 30) and the healthy control group (n = 35).

RESULTS

The analysis showed that the HRQoL in people with AE is reduced in comparison with the control population. The study group consisted of 15 (50.0%) men and 15 (50.0%) women; the control group of 16 (45.7%) men and 19 (54.3%) women. The mean age was 55.73 ± 16.65 years, while that of the control group was 54.57 ± 15.34 years. The physical quality of life in patients with AE (45.21 ± 11.42) was not significantly less than that of the control group (50.54 ± 10.52); p = 0.0568. Nevertheless, AE-patients show lower SF-36 scores for the physical quality of life. For the mental quality of life, patients with AE had a significantly lower score (45.46 ± 10.57) than the control group (51.57 ± 9.04); p = 0.0154.

CONCLUSIONS

The HRQoL in people with AE is reduced in comparison with a control population. Assessment of the physical and mental quality of life in patients with AE may help to evaluate the patient outcome.

Hunting Poses Only a Low Risk for Alveolar Echinococcosis

The Austrian province of Tyrol belongs to the areas where the alveolar echinococcosis (AE) caused by the fox tapeworm Echinococcus multilocularis (E. multilocularis) is highly endemic. In Central Europe and since 2011 in Austria, a growing incidence of human cases of AE has been observed, presumably linked with increasing fox populations infected by the fox tapeworm E. multilocularis. Hunting and the related activities put hunters in a high-risk group, and they are considered particularly vulnerable for the contraction of an AE. In light of this risk and the increased number of AE cases made public in Austria, the objective of the study was to investigate the prevalence of AE in hunters and to provide a possible connection to the incidence increase. In 2015 and 2016, we examined 813 serums of active hunters from all nine districts of Tyrol and serologically tested them for E. multilocularis antibodies. Twenty-one (2.58%) positive results in ELISA were detected via Western blot (WB), and only one (0.12%) serum showed a low positive reaction. No lesion in the liver parenchyma could be detected by abdominal ultrasonography in this patient so far, but the risk of developing alveolar echinococcosis remains for this WB-positive hunter. Risk factor analysis of these 813 hunters revealed that 697 (85.7%) hunted red foxes regularly and 332 (40.8%) of those skinned them as well. Three hundred and eighteen (39.1%) out of the 813 hunters were owners of hunting dogs; 89 (10.9%) and 243 (29.9%) were owners of non-hunting dogs and cats, respectively. Our results indicate that hunters do not have a greater risk of infection with E. multilocularis compared to non-hunters in Austria. The cause of the unexpected increase in AE cases in Austria remains unclear.

Identifying drivers of fox and cat faecal deposits in kitchen gardens in order to evaluate measures for reducing contamination of fresh fruit and vegetables

Preventing foodborne pathogen contamination of raw fruit and vegetables in the field is critically important for public health. Specifically, it involves preventing faecal deposit by wildlife or domestic animals in fields of crops and kitchen gardens. The present study aims to identify the drivers of fox, dog and cat faecal deposits in kitchen gardens in order to mitigate the risk of contamination of raw produce with parasites shed in carnivore faeces. The focus was on Echinococcus multilocularis, ranked highest in the importance of foodborne parasites in Europe, but attention was also paid to other parasites of major concern - Toxoplasma gondii and Toxocara spp. During the winters of 2014 to 2016, faecal samples were collected from 192 kitchen gardens located in north-eastern France. From these samples, 77% contained scat of carnivores. Molecular analyses revealed that 59% of the 1016 faeces collected were from cats, 31% from foxes, and 10% from dogs. The ease of accessibility to kitchen gardens, the presence of food in the vicinity, and the composition of the surrounding vegetation were used to explain the distribution of fox and cat faeces. Generalized Linear Mixed Effects modelling showed that: i) fencing was not efficient in reducing cat faecal deposits, but drastically decreases those of foxes; ii) the abundance of Microtus sp. indicates a reason for the presence of both fox and cat faecal deposits, iii) the abundance of Arvicola terrestris, the proximity of fruit trees or farms and the predominance of forest and grassland around the village are all drivers of fox faecal deposits. These results point to the importance of fencing around kitchen gardens located in E. multilocularis endemic areas, particularly those surrounded by forest and grassland or close to fruit trees or farms.

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192 kitchen gardens sampled 6 times over 2 winters, 1016 carnivore faeces collected.

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Fencing, food and vegetation cover tested as explanatory factors for faeces location.

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Numerous cat faeces, even in enclosed gardens. Microtus sp. drives their deposit.

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Garden accessibility, food and vegetation cover drive the faecal deposits of foxes.

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Fencing off kitchen gardens should be encouraged in E. multilocularis endemic areas.

Koutsoumanis K, Allende A, Alvarez-Ordóñez A, Bolton D, Bover-Cid S, Chemaly M, Davies R, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Cacciò S, Chalmers R, Deplazes P, Devleesschauwer B, Innes E, Romig T, van der Giessen J, Hempen M, Van der Stede Y, Robertson L. Public health risks associated with food-borne parasites

Parasites are important food‐borne pathogens. Their complex lifecycles, varied transmission routes, and prolonged periods between infection and symptoms mean that the public health burden and relative importance of different transmission routes are often difficult to assess. Furthermore, there are challenges in detection and diagnostics, and variations in reporting. A Europe‐focused ranking exercise, using multicriteria decision analysis, identified potentially food‐borne parasites of importance, and that are currently not routinely controlled in food. These are Cryptosporidium spp., Toxoplasma gondii and Echinococcus spp. Infection with these parasites in humans and animals, or their occurrence in food, is not notifiable in all Member States. This Opinion reviews current methods for detection, identification and tracing of these parasites in relevant foods, reviews literature on food‐borne pathways, examines information on their occurrence and persistence in foods, and investigates possible control measures along the food chain. The differences between these three parasites are substantial, but for all there is a paucity of well‐established, standardised, validated methods that can be applied across the range of relevant foods. Furthermore, the prolonged period between infection and clinical symptoms (from several days for Cryptosporidium to years for Echinococcus spp.) means that source attribution studies are very difficult. Nevertheless, our knowledge of the domestic animal lifecycle (involving dogs and livestock) for Echinoccocus granulosus means that this parasite is controllable. For Echinococcus multilocularis, for which the lifecycle involves wildlife (foxes and rodents), control would be expensive and complicated, but could be achieved in targeted areas with sufficient commitment and resources. Quantitative risk assessments have been described for Toxoplasma in meat. However, for T. gondii and Cryptosporidium as faecal contaminants, development of validated detection methods, including survival/infectivity assays and consensus molecular typing protocols, are required for the development of quantitative risk assessments and efficient control measures.

Alveolar echinococcosis in Germany, 1992-2016. An update based on the newly established national AE database

PURPOSE

Alveolar echinococcosis is a rare disease caused by the parasite Echinococcus multilocularis. The newly established national database should enable us to determine high-risk areas and evaluate the endemic levels.

METHODS

The national database was implemented using SQL Workbench. We used EpiInfo™ software to display the prevalence of disease. Moran's I geodata analysis according to cluster and high risk areas was performed with GeoDa™. SAS Version 9.2 was used for the statistical analysis of the cases (n = 523).

RESULTS

The analysis showed a concentration of cases in Baden-Württemberg and Bavaria. Moran's I showed a heterogeneous case distribution throughout Germany (I = 0.208815, Z = 32.6175, p < 0.001). In the period from 1992 to 2016, the prevalence was 0.64/100,000 inhabitants in the whole of Germany, 2.18/100,000 inhabitants in Baden-Württemberg and 1.48/100,000 inhabitants in Bavaria. The analysis also revealed a difference between men and women, with a prevalence of 0.58/100,000 and 0.69/100,000, respectively. The analysis of spatial autocorrelation and possible risk areas showed that the southeast regions of Baden-Württemberg (I = 0.188514, Z = 11.3197, p < 0.001) and the southwest part of Bavaria (I = 0.176953, Z = 13.5144, p < 0.001) constitute the high risk areas.

CONCLUSIONS

The prevalence of disease is noticeably high in the Swabian Jura, the Bavarian Alps and the Alpine foothills. Raising awareness and educating doctors in high risk areas may prevent new cases and assist in earlier diagnosis.

Detection of Echinococcus multilocularis and other foodborne parasites in fox, cat and dog faeces collected in kitchen gardens in a highly endemic area for alveolar echinococcosis

Echinococcus multilocularis, Toxoplasma gondii and Toxocara spp. are foodborne parasites whose eggs or oocysts are spread in the environment via canid or felid faeces. They can cause infections in humans following the raw consumption of contaminated fruit or vegetables. In this study, their occurrence was investigated by quantitative polymerase chain reaction (qPCR) in 254 carnivore faeces deposited in 94 kitchen gardens of northeastern France that were sampled between two and six times from October 2011 to April 2013. Less than 25% of the sampled kitchen gardens contained more than 75% of the collected faeces. Of the 219 faeces that could be attributed to an emitter, cat accounted for 58%, fox for 32% and dog for 10%. Echinococcus multilocularis was detected in 35%, 11% and 7% of fox, dog and cat faeces, respectively, and Toxocara spp. in 33%, 12% and 5.5% of cat, fox and dog faeces, respectively. Toxoplasma gondii was detected in 2/125 cat faeces and 2/21 dog faeces. The 34 faeces that tested positive for E. multilocularis were found in only 19 out of the 94 sampled kitchen gardens, and the 40 faeces that tested positive for Toxocara spp. were found in 28 of them. Consequently, some kitchen gardens appeared particularly at risk of human exposure to foodborne parasites, including E. multilocularis responsible for alveolar echinococcosis (AE), which is a serious zoonosis. In endemic areas, kitchen garden owners should be informed about the zoonotic risk linked to carnivore faeces deposits and encouraged to set up preventive measures.

A flotation/sieving method to detect Echinococcus multilocularis and Toxocara spp. eggs in soil by real-time PCR

Soil can be a source of human infection by many zoonotic helminth species including Echinococcus multilocularis and Toxocara spp. The prevention of alveolar echinococcosis could be greatly improved through the identification of at-risk areas. Yet very few data are available about the detection of E. multilocularis in soil, while more studies have been reported for Toxocara spp. Identification of soil contamination by E. multilocularis eggs requires the use of specific methods. This study describes the development of a method for the detection of E. multilocularis in soil samples with the concentration of eggs using a flotation/sieving method and detection by duplex real-time polymerase chain reaction (PCR). Toxocara spp. egg detection was also undertaken due to the widespread presence of this parasite in soil, despite it being considered less pathogenic. Method sensitivity of 100% was reached for the detection of 10 E. multilocularis eggs spiked in 10 g of soil. Concerning Toxocara spp., method sensitivity was lower but assumed to be due to the reduced effectiveness of the DNA extraction protocol. The parasitological status for E. multilocularis and Toxocara spp. of 63 carnivore fecal samples collected in highly endemic rural areas of France and of soil samples collected under and near these fecal samples was compared. The contamination of soil samples collected under positive fecal samples for E. multilocularis (n = 3) or Toxocara spp. (n = 19) confirmed the transfer of eggs from the definitive host to the environment.

Potential risk factors associated with human alveolar echinococcosis: Systematic review and meta-analysis

Background

Human alveolar echinococcosis (AE) is a severe zoonotic disease caused by the metacestode stage of Echinococcus multilocularis. AE is commonly associated with a long incubation period that may last for more than ten years. The objective of this systematic literature review was to identify and summarize the current knowledge on statistically relevant potential risk factors (PRFs) associated with AE in humans.

Methodology/Principal findings

Six bibliographic databases were searched, generating a total of 1,009 publications. Following the removal of duplicate records and the exclusion of papers that failed to meet the criteria of a previously agreed a priori protocol, 23 publications were retained; however, 6 of these did not contain data in a format that allowed their inclusion in the meta-analysis. The remaining 17 publications (6 case-control and 11 cross-sectional studies) were meta-analysed to investigate associations between AE and PRFs. Pooled odds ratios (OR) were used as a measure of effect and separately analysed for case-control and cross-sectional studies. In the case-control studies, the following PRFs for human AE showed higher odds of outcome: “dog ownership”, “cat ownership”, “have a kitchen garden”, “occupation: farmer”, “haymaking in meadows not adjacent to water”, “went to forests for vocational reasons”, “chewed grass” and “hunting / handling foxes”. In the cross-sectional studies, the following PRFs showed higher odds of outcome: “dog ownership”, “play with dogs”, “gender: female”, “age over 20 years”, “ethnic group: Tibetan”, “low income”, “source of drinking water other than well or tap”, “occupation: herding” and “low education”. Our meta-analysis confirmed that the chance of AE transmission through ingestion of food and water contaminated with E. multilocularis eggs exists, but showed also that food- and water-borne PRFs do not significantly increase the risk of infection.

Conclusions/significance

This systematic review analysed international peer-reviewed articles that have over the years contributed to our current understanding of the epidemiology of human AE. The identification of potential risk factors may help researchers and decision makers improve surveillance and/or preventive measures that aim at decreasing human infection with E. multilocularis. More primary studies are needed to confirm potential risk factors and their role in the epidemiology of human AE.

Human alveolar echinococcosis is a severe zoonotic disease caused by the metacestode stage of the tapeworm Echinococcus multilocularis. The objective of this systematic literature review was to identify and summarize the current knowledge on potential risk factors associated with human alveolar echinococcosis. The categories of potential risk factors included dog-related factors such as dog ownership or play with dogs; vocational factors like being a farmer or handling foxes; human habits such as chewing grass; gender (being female) and socio-cultural factors like being Tibetan or having a low income or poor education, which may be relevant only in particular endemic areas. The identification of potential risk factors may help identify strategies that aim to decrease human infection with E. multilocularis.

Death by food

Although death from food is not an uncommon finding in forensic facilities worldwide, the range of underlying lethal mechanisms and associated conditions that should be sought at the time of autopsy is quite disparate. Deaths may occur from i) infectious agents including bacteria, viruses, protozoa, cestodes, nematodes and prions; ii) natural toxins including amanita toxins, tetrodotoxin, ciguatera and scombroid; iii) anaphylaxis; iv) poisoning; v) mechanical issues around airway and gut obstruction and/or perforation; and vi) miscellaneous causes. Food-related deaths are important in terms of global mortality, and thus autopsies need to be comprehensive with full ancillary testing. Medicolegal matters may involve issues concerning likely exposure to infectious agents, possible foods ingested, the declared content and possible components of food, the significance of toxicological analyses, and aspects of duty of care in cases of café coronary syndrome and gastroenteritis while in care.

Disseminated alveolar echinococcosis resembling metastatic malignancy: a case report

Background

Alveolar echinococcosis is a potentially lethal zoonosis caused by larval forms of the tapeworm Echinococcus multilocularis.

Humans are aberrant intermediate hosts who become infected by ingestion of egg-contaminated food or water or via physical contact with domestic or wild animals that carry the parasite in their small intestine. In humans, the disease usually affects the liver and can spread to other organs causing metastatic infiltration. In this report, we describe an advanced presentation of human alveolar echinococcosis mimicking metastatic malignancy.

Case presentation

A 62-year-old white woman was evaluated for fever, jaundice, and abdominal pain, associated with significant weight loss. She lived in a rural area in Switzerland and used to eat wild forest fruits and mushrooms. She owned cats that used to hunt rodents.

On physical examination, she appeared severely ill with cachexia, altered mental status, jaundice, and massive hepatomegaly. Laboratory tests showed cholestasis with preserved liver function.

An abdominal computed tomography scan showed an enlarged liver with a huge cystic mass in the right lobe extending into the left lobe, infiltrating her hepatic hilum, causing intrahepatic bile duct dilation and occlusion of her right portal vein. A chest computed tomography scan showed multiple calcified bilateral pulmonary nodules. Her clinical and radiological presentation resembled an advanced neoplastic disease. Serologic tests for Echinococcus multilocularis were positive.

The diagnosis of alveolar echinococcosis was established on her past history of exposure, imaging, and serology results.

Conclusions

Clinical presentation and radiologic imaging findings of disseminated alveolar echinococcosis can mimic metastatic malignancy, and diagnosis can be challenging in atypically advanced cases. As the incidence of human alveolar echinococcosis appears to be increasing in Europe and Switzerland, physicians should be aware of alveolar echinococcosis, its epidemiology, and its clinical features.

Fresh fruits, vegetables and mushrooms as transmission vehicles for Echinococcus multilocularis in highly endemic areas of Poland: reply to concerns

Echinococcus multilocularis is a tapeworm that may cause alveolar echinococcosis (AE), one of the most dangerous parasitic zoonoses. As in the case of other foodborne diseases, unwashed fruits and vegetables, contaminated with dispersed forms of E. multilocularis, may serve as an important transmission route for this parasite. In this article, we reply to the incorrect interpretation of results of our study concerning the detection of E. multilocularis DNA in fresh fruit, vegetable and mushroom samples collected from the highly endemic areas of the Warmia-Masuria Province, Poland, to dispel any doubts. The accusations formulated by the commentators concerning our paper are unfounded; moreover, these commentators demand information which was beyond the purview of our study. Making generalisations and drawing far-reaching conclusions from our work is also unjustified. The majority of positive samples were found in only a few hyperendemic communities; this information corresponds with the highest number of both infected foxes and AE cases in humans recorded in this area. Our findings indicate that E. multilocularis is present in the environment and may create a potential risk for the inhabitants. These people should simply be informed to wash fruits and vegetables before eating. No additional far-reaching conclusions should be drawn from our data. We believe these commentators needlessly misinterpreted our results and disseminated misleading information. Nevertheless, we would like to encourage any readers simply to contact us if any aspects of our study are unclear.

Cystic Echinococcosis Epidemiology in Spain Based on Hospitalization Records, 1997-2012

BACKGROUND

Cystic echinococcosis (CE) is a parasitic disease caused by the tapeworm Echinococcus granulosus. Although present throughout Europe, deficiencies in the official reporting of CE result in under-reporting and misreporting of this disease, which in turn is reflected in the wrong opinion that CE is not an important health problem. By using an alternative data source, this study aimed at describing the clinical and temporal-spatial characteristics of CE hospitalizations in Spain between 1997 and 2012.

METHODOLOGY/PRINCIPAL FINDINGS

We performed a retrospective descriptive study using the Hospitalization Minimum Data Set (CMBD in Spanish). All CMBD's hospital discharges with echinococcosis diagnosis placed in first diagnostic position were reviewed. Hospitalization rates were computed and clinical characteristics were described. Spatial and temporal distribution of hospital discharges was also assessed. Between 1997 and 2012, 14,010 hospitalizations with diagnosis of CE were recorded, 55% were men and 67% were aged over 45 years. Pediatric hospitalizations occurred during the whole study period. The 95.2% were discharged at home, and only 1.7% were exitus. The average cost was 8,439.11 €. The hospitalization rate per 100,000 per year showed a decreasing trend during the study period. All the autonomous communities registered discharges, even those considered as non-endemic. Maximum rates were reached by Extremadura, Castilla-Leon and Aragon. Comparison of the CMBD data and the official Compulsory Notifiable Diseases (CND) reports from 2005 to 2012 showed that official data were lower than registered hospitalization discharges.

CONCLUSIONS

Hospitalizations distribution was uneven by year and autonomous region. Although CE hospitalization rates have decreased considerably due to the success of control programs, it remains a public health problem due to its severity and economic impact. Therefore, it would be desirable to improve its oversight and surveillance, since officially reported data are underestimating the real burden of CE in Spain.

Detection of taeniid (Taenia spp., Echinococcus spp.) eggs contaminating vegetables and fruits sold in European markets and the risk for metacestode infections in captive primates

Due to frequent cases of alveolar echinococcosis (AE) in captive primates in Europe, 141 samples of food, which consisting of vegetables and fruits, were investigated for contamination with egg-DNA of taeniids. Each sample consisted of at least 40 heads of lettuce as well as various vegetables and fruits. The samples were purchased at different times of the year: either from September to November (autumn), originating from greenhouses or fields in the Basel region in the North of Switzerland, or in April and May (spring) when fruit and vegetables are sourced from throughout Europe from various wholesalers. Each sample was washed, and the washing water sieved through mesh apertures of 50 μm and 21 μm, respectively. The debris, including taeniid eggs, collected on the 21 μm sieve were investigated by a multiplex PCR-analysis followed by direct sequencing. In 17 (18%) of the 95 samples collected in autumn, taeniid-DNA was detected (Taenia hydatigena in four, Taenia ovis in three, Taenia polyacantha in two and Hydatigera (Taenia) taeniaeformis in five cases). Similarly, in 13 (28%) of the 46 samples collected during spring taeniid-DNA was detected (Echinococcus granulosus s.l. in two, Taenia crassiceps in one, T. hydatigena in two, Taenia multiceps/Taenia serialis in two, Taenia saginata in one and H. taeniaeformis in five cases). Although DNA of Echinococcus multilocularis was not found specifically in this study, the detection of other fox taeniids reveals that vegetables and fruit fed to the primates at the Zoo Basel at different times of the year and from different origin are contaminated with carnivore's faeces and therefore act as a potential source of AE infections.

The first detection of Echinococcus multilocularis DNA in environmental fruit, vegetable, and mushroom samples using nested PCR

The aim of this study was to estimate the presence of Echinococcus multilocularis DNA in fruits, vegetables, and mushrooms in rural areas of Varmia-Masuria Province, Poland, which is the region with the highest number of human alveolar echinococcosis (AE) cases in this country. Recovery tests showed that E. multilocularis DNA is detectable in samples contaminated with at least 100 eggs of this tapeworm. In total, 103 environmental fruit, vegetable, and mushroom samples collected in forests, plantations, and kitchen gardens were analyzed using nested PCR assay based on the mitochondrial 12S ribosomal RNA (rRNA) gene. The parasite DNA was detected in 23.3 % of the samples. Sequencing confirmed that the obtained PCR products represented E. multilocularis. This study is the first environmental survey of the presence of E. multilocularis DNA in fruits, vegetables, and mushrooms intended for consumption. The results clearly demonstrate that it may be a direct source of human infections and shows the need to educate the public about the threat, especially people living in at-risk areas.

The role of wildlife in the transmission of parasitic zoonoses in peri-urban and urban areas

During the last 100 years in many countries of the world, there have been dramatic changes in natural/rural landscapes due to urbanization. Since many wildlife species are unable to adapt to these alterations in their environment, urbanization is commonly responsible for a decline of biodiversity in areas of urban development. In contrast, some wild animal species are attracted to peri-urban and urban habitats due to the availability of an abundant food supply and the presence of structures in which to shelter. Urban foxes and/or raccoons are common sights in many peri-urban and urban areas of Europe where they can reach far higher population densities than in their natural habitats. The same is true for foxes and dingoes in some urban areas of Australia. Unfortunately, some of these highly adaptable species are also hosts for a number of parasites of public health and veterinary importance. Due to the complexity of many parasitic life cycles involving several host species, the interactions between wild animals, domestic animals and humans are not fully understood. The role of potential hosts for transmission of a zoonotic disease in urban or peri-urban areas cannot be extrapolated from data obtained in rural areas. Since more than 75% of human diseases are of zoonotic origin, it is important to understand the dynamics between wildlife, domestic animal species and humans in urbanized areas, and to conduct more focused research on transmission of zoonotic parasites including arthropod vectors under such conditions.

Emerging and Re-Emerging Zoonoses of Dogs and Cats

Simple Summary

Dogs and cats have been sharing our environment for a long time and as pets they bring major psychological well-being to our modern urbanized society. However, they still can be a source of human infection by various pathogens, including viruses, bacteria, parasites, and fungi.

Abstract

Since the middle of the 20th century, pets are more frequently considered as “family members” within households. However, cats and dogs still can be a source of human infection by various zoonotic pathogens. Among emerging or re-emerging zoonoses, viral diseases, such as rabies (mainly from dog pet trade or travel abroad), but also feline cowpox and newly recognized noroviruses or rotaviruses or influenza viruses can sicken our pets and be transmitted to humans. Bacterial zoonoses include bacteria transmitted by bites or scratches, such as pasteurellosis or cat scratch disease, leading to severe clinical manifestations in people because of their age or immune status and also because of our closeness, not to say intimacy, with our pets. Cutaneous contamination with methicillin-resistant Staphylococcus aureus, Leptospira spp., and/or aerosolization of bacteria causing tuberculosis or kennel cough are also emerging/re-emerging pathogens that can be transmitted by our pets, as well as gastro-intestinal pathogens such as Salmonella or Campylobacter. Parasitic and fungal pathogens, such as echinococcosis, leishmaniasis, onchocercosis, or sporotrichosis, are also re-emerging or emerging pet related zoonoses. Common sense and good personal and pet hygiene are the key elements to prevent such a risk of zoonotic infection.

Dynamics of the force of infection: insights from Echinococcus multilocularis infection in foxes

Characterizing the force of infection (FOI) is an essential part of planning cost effective control strategies for zoonotic diseases. Echinococcus multilocularis is the causative agent of alveolar echinococcosis in humans, a serious disease with a high fatality rate and an increasing global spread. Red foxes are high prevalence hosts of E. multilocularis. Through a mathematical modelling approach, using field data collected from in and around the city of Zurich, Switzerland, we find compelling evidence that the FOI is periodic with highly variable amplitude, and, while this amplitude is similar across habitat types, the mean FOI differs markedly between urban and periurban habitats suggesting a considerable risk differential. The FOI, during an annual cycle, ranges from (0.1,0.8) insults (95% CI) in urban habitat in the summer to (9.4, 9.7) (95% CI) in periurban (rural) habitat in winter. Such large temporal and spatial variations in FOI suggest that control strategies are optimal when tailored to local FOI dynamics.

Human alveolar echinococcosis (AE) is caused by the fox tapeworm E. multilocularis and has a high fatality rate if untreated. The frequency of the tapeworm in foxes can be reduced through the regular distribution of anthelmintic baits and thus decrease the risk of zoonotic transmission. Here, we estimate the force of infection to foxes using a mathematical model and data from necropsied foxes. The results suggest that the frequency of anthelmintic baiting of foxes can be optimised to local variations in transmission that depend upon season and type of fox habitat.

Populations at risk for alveolar echinococcosis, France

During 1982–2007, alveolar echinococcosis (AE) was diagnosed in 407 patients in France, a country previously known to register half of all European patients. To better define high-risk groups in France, we conducted a national registry-based study to identify areas where persons were at risk and spatial clusters of cases. We interviewed 180 AE patients about their way of life and compared responses to those of 517 controls. We found that almost all AE patients lived in 22 départements in eastern and central France (relative risk 78.63, 95% CI 52.84–117.02). Classification and regression tree analysis showed that the main risk factor was living in AE-endemic areas. There, most at-risk populations lived in rural settings (odds ratio [OR] 66.67, 95% CI 6.21–464.51 for farmers and OR 6.98, 95% CI 2.88–18.25 for other persons) or gardened in nonrural settings (OR 4.30, 95% CI 1.82–10.91). These findings can help sensitization campaigns focus on specific groups.

Human alveolar echinococcosis in Poland: 1990-2011

Background

Alveolar echinococcosis (AE) caused by Echinococcus multilocularis infections is a dangerous old disease in the Northern Hemisphere. The aim of the paper was to collect and analyze data on human AE in Poland in the last two decades.

Methodology/Principal Findings

The sources of data were both the cases officially registered and detected by an active field and laboratory surveillance. The cases were verified by clinical, epidemiological, and laboratory criteria. Altogether 121 human cases of AE were detected. Among these 83 (68,6%) cases were classified as confirmed, 16 as probable and 22 as possible. During the two decades a continuous increase in detection rate was noticed. The cases were 6–82 years old at the time of diagnosis (mean - 47.7 years). Sex ratio M/F was 0.86/1.0. The AE was fatal in 23 (19%) patients (mean age at death - 54.1 years). Family agglomeration of AE was found in 4 foci, involving 9 patients. Seventy six of the cases were diagnosed in an advanced stage of disease. In all cases the liver was the primary location of AE. In 30 (24.8%) patients a spread to other organs was observed. Ninety four of the patients were treated with albendazole. In 73 (60%) patients a surgical operation was performed, including 15 liver transplantations.

Conclusions/Significance

The studies confirmed that AE is an emerging disease in Poland, which is the fourth country in Europe with over 120 cases detected. The results also indicate the need of a wider national programme for implementation of screening in the highest AE risk areas (north-eastern Poland) with an effort to increase the public awareness of the possibility of contracting E. multilocularis, and above all, training of the primary care physicians in the recognition of the risk of AE to allow for an early detection of this dangerous disease.

Human alveolar echinococcosis (AE) is a consequence of accidental ingestion of the eggs of the tapeworm Echinococcus multilocularis. AE constitutes a serious and increasing medical and epidemiological problem in many countries including Poland. The natural environments with a high AE prevalence are the areas where the definitive hosts (foxes, raccoons) and the intermediate hosts (rodents) live. The increasing population of infected foxes that penetrate nearby the village and urban buildings and infected dogs poses a certain risk to human health. This report is a joint clinical and epidemiological analysis of 121 AE cases recorded in the years 1990–2011 in Poland. The highest percentage of E. multilocularis infected foxes in the north-eastern regions of Poland (about 40% of the examined population infected) bears a clear-cut relation to the highest incidence of detected AE human cases in those areas. An epidemiological and clinical survey of the local population conducted for over a dozen years has contributed to the discovery of several new AE cases. Alveolar echinococcosis in humans caused by Echinococcus multilocularis infection belongs to the emerging diseases in Poland where a continuous increase in the detection rate was noticed during the last two decades.

The first locally acquired human infection of Echinococcus multilocularis in The Netherlands

In the northern part of Western Europe, Echinococcus multilocularis is primarily detected in and spreading among foxes. The present case marks E. multilocularis as an emerging pathogen for humans, as it describes the first human case of probably locally acquired E. multilocularis in The Netherlands, with various interesting clinical aspects.

Combining information from surveys of several species to estimate the probability of freedom from Echinococcus multilocularis in Sweden, Finland and mainland Norway

Background

The fox tapeworm Echinococcus multilocularis has foxes and other canids as definitive host and rodents as intermediate hosts. However, most mammals can be accidental intermediate hosts and the larval stage may cause serious disease in humans. The parasite has never been detected in Sweden, Finland and mainland Norway. All three countries require currently an anthelminthic treatment for dogs and cats prior to entry in order to prevent introduction of the parasite. Documentation of freedom from E. multilocularis is necessary for justification of the present import requirements.

Methods

The probability that Sweden, Finland and mainland Norway were free from E. multilocularis and the sensitivity of the surveillance systems were estimated using scenario trees. Surveillance data from five animal species were included in the study: red fox (Vulpes vulpes), raccoon dog (Nyctereutes procyonoides), domestic pig, wild boar (Sus scrofa) and voles and lemmings (Arvicolinae).

Results

The cumulative probability of freedom from EM in December 2009 was high in all three countries, 0.98 (95% CI 0.96-0.99) in Finland and 0.99 (0.97-0.995) in Sweden and 0.98 (0.95-0.99) in Norway.

Conclusions

Results from the model confirm that there is a high probability that in 2009 the countries were free from E. multilocularis. The sensitivity analyses showed that the choice of the design prevalences in different infected populations was influential. Therefore more knowledge on expected prevalences for E. multilocularis in infected populations of different species is desirable to reduce residual uncertainty of the results.

The global burden of alveolar echinococcosis

BACKGROUND

Human alveolar echinococcosis (AE) is known to be common in certain rural communities in China whilst it is generally rare and sporadic elsewhere. The objective of this study was to provide a first estimate of the global incidence of this disease by country. The second objective was to estimate the global disease burden using age and gender stratified incidences and estimated life expectancy with the disease from previous results of survival analysis. Disability weights were suggested from previous burden studies on echinococcosis.

METHODOLOGY/PRINCIPAL FINDINGS

We undertook a detailed review of published literature and data from other sources. We were unable to make a standardised systematic review as the quality of the data was highly variable from different countries and hence if we had used uniform inclusion criteria many endemic areas lacking data would not have been included. Therefore we used evidence based stochastic techniques to model uncertainty and other modelling and estimating techniques, particularly in regions where data quality was poor. We were able to make an estimate of the annual global incidence of disease and annual disease burden using standard techniques for calculation of DALYs. Our studies suggest that there are approximately 18,235 (CIs 11,900-28,200) new cases of AE per annum globally with 16,629 (91%) occurring in China and 1,606 outside China. Most of these cases are in regions where there is little treatment available and therefore will be fatal cases. Based on using disability weights for hepatic carcinoma and estimated age and gender specific incidence we were able to calculate that AE results in a median of 666,434 DALYs per annum (CIs 331,000-1.3 million).

CONCLUSIONS/SIGNIFICANCE

The global burden of AE is comparable to several diseases in the neglected tropical disease cluster and is likely to be one of the most important diseases in certain communities in rural China on the Tibetan plateau.

Food-borne diseases - the challenges of 20 years ago still persist while new ones continue to emerge

The burden of diseases caused by food-borne pathogens remains largely unknown. Importantly data indicating trends in food-borne infectious intestinal disease is limited to a few industrialised countries, and even fewer pathogens. It has been predicted that the importance of diarrhoeal disease, mainly due to contaminated food and water, as a cause of death will decline worldwide. Evidence for such a downward trend is limited. This prediction presumes that improvements in the production and retail of microbiologically safe food will be sustained in the developed world and, moreover, will be rolled out to those countries of the developing world increasingly producing food for a global market. In this review evidence is presented to indicate that the microbiological safety of food remains a dynamic situation heavily influenced by multiple factors along the food chain from farm to fork. Sustaining food safety standards will depend on constant vigilance maintained by monitoring and surveillance but, with the rising importance of other food-related issues, such as food security, obesity and climate change, competition for resources in the future to enable this may be fierce. In addition the pathogen populations relevant to food safety are not static. Food is an excellent vehicle by which many pathogens (bacteria, viruses/prions and parasites) can reach an appropriate colonisation site in a new host. Although food production practices change, the well-recognised food-borne pathogens, such as Salmonella spp. and Escherichia coli, seem able to evolve to exploit novel opportunities, for example fresh produce, and even generate new public health challenges, for example antimicrobial resistance. In addition, previously unknown food-borne pathogens, many of which are zoonotic, are constantly emerging. Current understanding of the trends in food-borne diseases for bacterial, viral and parasitic pathogens has been reviewed. The bacterial pathogens are exemplified by those well-recognized by policy makers; i.e. Salmonella, Campylobacter, E. coli and Listeria monocytogenes. Antimicrobial resistance in several bacterial food-borne pathogens (Salmonella, Campylobacter, Shigella and Vibrio spp., methicillin resistant Staphylcoccus aureas, E. coli and Enterococci) has been discussed as a separate topic because of its relative importance to policy issues. Awareness and surveillance of viral food-borne pathogens is generally poor but emphasis is placed on Norovirus, Hepatitis A, rotaviruses and newly emerging viruses such as SARS. Many food-borne parasitic pathogens are known (for example Ascaris, Cryptosporidia and Trichinella) but few of these are effectively monitored in foods, livestock and wildlife and their epidemiology through the food-chain is poorly understood. The lessons learned and future challenges in each topic are debated. It is clear that one overall challenge is the generation and maintenance of constructive dialogue and collaboration between public health, veterinary and food safety experts, bringing together multidisciplinary skills and multi-pathogen expertise. Such collaboration is essential to monitor changing trends in the well-recognised diseases and detect emerging pathogens. It will also be necessary understand the multiple interactions these pathogens have with their environments during transmission along the food chain in order to develop effective prevention and control strategies.

Echinococcus multilocularis in Europe--state of the art

New information has become available on the epidemiological situation of Echinococcus multilocularis in Europe. Additional endemic areas have been identified, and, in some areas, prevalences in foxes have drastically increased. In addition, some neozootic mammals may by now be involved in the lifecycle. The parasite is now widespread in urban and suburban areas in central Europe. The number of human cases of alveolar echinococcosis is small, but still underreported, and is likely to increase in the near future. Trials to counteract the spread of this parasite have been performed by application of anthelmintics to foxes via baits, and gave encouraging results on different spatial scales.

Survey of public knowledge about Echinococcus multilocularis in four European countries: need for proactive information

Background

Public information about prevention of zoonoses should be based on the perceived problem by the public and should be adapted to regional circumstances. Growing fox populations have led to increasing concern about human alveolar echinococcosis, which is caused by the fox tapeworm Echinococcus multilocularis. In order to plan information campaigns, public knowledge about this zoonotic tapeworm was assessed.

Methods

By means of representative telephone interviews (N = 2041), a survey of public knowledge about the risk and the prevention of alveolar echinococcosis was carried out in the Czech Republic, France, Germany and Switzerland in 2004.

Results

For all five questions, significant country-specific differences were found. Fewer people had heard of E. multilocularis in the Czech Republic (14%) and France (18%) compared to Germany (63%) and Switzerland (70%). The same effect has been observed when only high endemic regions were considered (Czech Republic: 20%, France: 17%, Germany: 77%, Switzerland: 61%). In France 17% of people who knew the parasite felt themselves reasonably informed. In the other countries, the majority felt themselves reasonably informed (54–60%). The percentage that perceived E. multilocularis as a high risk ranged from 12% (Switzerland) to 43% (France). In some countries promising measures as deworming dogs (Czech Republic, Switzerland) were not recognized as prevention options.

Conclusion

Our results and the actual epidemiological circumstances of AE call for proactive information programs. This communication should enable the public to achieve realistic risk perception, give clear information on how people can minimize their infection risk, and prevent exaggerated reactions and anxiety.

Rudolf Virchow and the recognition of alveolar echinococcosis, 1850s

Virchow proved that the disease “alveolar colloid” was caused by an Echinococcus sp.

Alveolar echinococcosis, which is caused by the larval stage of the fox tapeworm Echinococcus multilocularis, is one of the most dangerous parasitic diseases. It is endemic in many parts of the Northern Hemisphere and an emerging health problem in the People’s Republic of China. In Europe and North America, human cases are rare, but concomitant with an increase in the population of the final host, the red fox, an increase of human infections is expected. Rudolf Virchow, the father of the concept of cellular pathology, determined in the 1850s that an Echinococcus sp. was the causative agent of this enigmatic emerging disease. In his famous publication in 1855, he described the clinical course of the disease, its macroscopic aspects, and histopathologic findings in detail. He also identified the disease formerly known as alveolar colloid of the liver to be an infection with the larval stage of an Echinococcus sp.

Echinococcosis in Tibetan populations, western Sichuan Province, China

This area has the highest prevalences of both forms of this disease in the world.

We screened 3,199 people from Shiqu County, Sichuan Province, China, for abdominal echinococcosis (hydatid disease) by portable ultrasound combined with specific serodiagnostic tests. Both cystic echinococcosis (CE) (Echinococcus granulosus infection) and alveolar echinococcosis (AE) (E. multilocularis) were co-endemic in this area at the highest village prevalence values recorded anywhere in the world: 12.9% were infected with one or the other form (6.8% CE and 6.2% AE). Prevalences of both CE and AE were significantly higher in female than male patients and increased with the age of the person screened. Pastoral herdsmen were at highest risk for infection (prevalence 19.0%). Prevalence of CE varied in 5 townships from 0% to 12.1%, whereas AE prevalence ranged from 0% to 14.3%. Risk factors associated with both infections included the number of owned dogs, frequency of contact with dogs, and sources of drinking water.