Watch and Wait Management of Inactive Cystic Echinococcosis - Does the Path to Inactivity Matter - Analysis of a Prospective Patient Cohort

The Diagnostic Challenge of Cystic Echinococcosis in Humans: First Assessment of Underreporting Rates in Mongolia

Cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus, is significantly underreported in Mongolia due to geographical remoteness, a lack of early diagnostics, and poor clinical management. This study aimed to provide a more accurate estimate of CE in Mongolia by comparing data from surgical (reported) and diagnosed (unreported) cases and assessing the challenges faced by rural doctors in disease management and surveillance. We collected data on surgical cases hospitalized between 2006 and 2016 and newly diagnosed CE cases in 2016 from eight provinces. Using a quasi-Poisson regression model, we extrapolated the collected data to estimate the number of diagnosed cases for the entire country. Additionally, forty health professionals from all 21 provinces rated local clinical management for CE through a questionnaire. The results reveal that surgical cases (2.2 per year) represent only one-eighth of diagnosed cases (15.9 per year). The laboratory facilities, disease reporting, and cyst classification usage scored below 2. These results highlight the significant underreporting of CE in Mongolia and urge human and animal health experts, along with policymakers, to invest in combating CE, particularly in remote provincial areas. This study also emphasizes the need for standard clinical management involving cyst classification according to the WHO-IWGE and seamless integration of CE reporting and monitoring mechanisms, which can significantly contribute to the national and global burden estimation of CE.

Treatment of uncomplicated hepatic cystic echinococcosis (hydatid disease)

BACKGROUND

Cystic echinococcosis is a parasitic infection mainly impacting people living in low- and middle-income countries. Infection may lead to cyst development within organs, pain, non-specific symptoms or complications including abscesses and cyst rupture. Treatment can be difficult and varies by country. Treatments include oral medication, percutaneous techniques and surgery. One Cochrane review previously assessed the benefits and harms of percutaneous treatment compared with other treatments. However, evidence for oral medication, percutaneous techniques and surgery in specific cyst stages has not been systematically investigated and the optimal choice remains uncertain.

OBJECTIVES

To assess the benefits and harms of medication, percutaneous and surgical interventions for treating uncomplicated hepatic cystic echinococcosis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, two other databases and two trial registries to 4 May 2023. We searched the reference lists of included studies, and contacted experts and researchers in the field for relevant studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in people with a diagnosis of uncomplicated hepatic cystic echinococcosis of World Health Organization (WHO) cyst stage CE1, CE2, CE3a or CE3b comparing either oral medication (albendazole) to albendazole plus percutaneous interventions, or to surgery plus albendazole. Studies comparing praziquantel plus albendazole to albendazole alone prior to or following an invasive intervention (surgery or percutaneous treatment) were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were symptom improvement, recurrence, inactive cyst at 12 months and all-cause mortality at 30 days. Our secondary outcomes were development of secondary echinococcosis, complications of treatment and duration of hospital stay. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included three RCTs with 180 adults and children with hepatic cystic echinococcosis. Two studies enrolled people aged 5 to 72 years, and one study enrolled children aged 6 to 14 years. One study compared standard catheterization plus albendazole with puncture, aspiration, injection and re-aspiration (PAIR) plus albendazole, and two studies compared laparoscopic surgery plus albendazole with open surgery plus albendazole. The three RCTs were published between 2020 and 2022 and conducted in India, Pakistan and Turkey. There were no other comparisons. Standard catheterization plus albendazole versus PAIR plus albendazole The cyst stages were CE1 and CE3a. The evidence is very uncertain about the effect of standard catheterization plus albendazole compared with PAIR plus albendazole on cyst recurrence (risk ratio (RR) 3.67, 95% confidence interval (CI) 0.16 to 84.66; 1 study, 38 participants; very low-certainty evidence). The evidence is very uncertain about the effects of standard catheterization plus albendazole on 30-day all-cause mortality and development of secondary echinococcosis compared to open surgery plus albendazole. There were no cases of mortality at 30 days or secondary echinococcosis (1 study, 38 participants; very low-certainty evidence). Major complications were reported by cyst and not by participant. Standard catheterization plus albendazole may increase major cyst complications compared with PAIR plus albendazole, but the evidence is very uncertain (RR 10.74, 95% CI 1.39 to 82.67; 1 study, 53 cysts; very low-certainty evidence). Standard catheterization plus albendazole may make little to no difference on minor complications compared with PAIR plus albendazole, but the evidence is very uncertain (RR 1.03, 95% CI 0.60 to 1.77; 1 study, 38 participants; very low-certainty evidence). Standard catheterization plus albendazole may increase the median duration of hospital stay compared with PAIR plus albendazole, but the evidence is very uncertain (4 (range 1 to 52) days versus 1 (range 1 to 15) days; 1 study, 38 participants; very low-certainty evidence). Symptom improvement and inactive cysts at 12 months were not reported. Laparoscopic surgery plus albendazole versus open surgery plus albendazole The cyst stages were CE1, CE2, CE3a and CE3b. The evidence is very uncertain about the effect of laparoscopic surgery plus albendazole on cyst recurrence in participants with CE2 and CE3b cysts compared to open surgery plus albendazole (RR 3.00, 95% CI 0.13 to 71.56; 1 study, 82 participants; very low-certainty evidence). The second study involving 60 participants with CE1, CE2 or CE3a cysts reported no recurrence in either group. The evidence is very uncertain about the effect of laparoscopic surgery plus albendazole on 30-day all-cause mortality in participants with CE1, CE2, CE3a or CE3b cysts compared to open surgery plus albendazole. There was no mortality in either group (2 studies, 142 participants; very low-certainty evidence). The evidence is very uncertain about the effect of laparoscopic surgery plus albendazole on major complications in participants with CE1, CE2, CE3a or CE3b cysts compared to open surgery plus albendazole (RR 0.50, 95% CI 0.13 to 1.92; 2 studies, 142 participants; very low-certainty evidence). Laparoscopic surgery plus albendazole may lead to slightly fewer minor complications in participants with CE1, CE2, CE3a or CE3b cysts compared to open surgery plus albendazole (RR 0.13, 95% CI 0.02 to 0.98; 2 studies, 142 participants; low-certainty evidence). Laparoscopic surgery plus albendazole may reduce the duration of hospital stay compared with open surgery plus albendazole (mean difference (MD) -1.90 days, 95% CI -2.99 to -0.82; 2 studies, 142 participants; low-certainty evidence). Symptom improvement, inactive cyst at 12 months and development of secondary echinococcosis were not reported.

AUTHORS' CONCLUSIONS

Percutaneous and surgical interventions combined with albendazole can be used to treat uncomplicated hepatic cystic echinococcosis; however, there is a scarcity of randomised evidence directly comparing these interventions. There is very low-certainty evidence to indicate that standard catheterization plus albendazole may lead to fewer cases of recurrence, more major complications and similar complication rates compared to PAIR plus albendazole in adults and children with CE1 and CE3a cysts. There is very low-certainty evidence to indicate that laparoscopic surgery plus albendazole may result in fewer cases of recurrence or fewer major complications compared to open surgery plus albendazole in adults and children with CE1, CE2, CE3a and CE3b cysts. Laparoscopic surgery plus albendazole may lead to slightly fewer minor complications. Firm conclusions cannot be drawn due to the limited number of studies, small sample size and lack of events for some outcomes.

Investigation of patients with new infection of echinococcal cyst in Sardinia, Italy

Cystic Echinococcosis (CE) is a zoonotic disease caused by the larval stage of a tapeworm of Taeniidae family, genus Echinococcus and species Echinococcus granulosus sensu lato (s.l.). CE is a worldwide public health problem and is highly incident in all Mediterranean areas. Following clinical, image techniques and serological investigations all 83 subjects involved in the study were diagnosed for CE. General and clinical data were entered into a database and evaluated. The 43.37% were female and 56.63% male, mean age was 50.71 while the range most represented (22.7%) was between 61->70 years. The purposes of our survey were to investigate these 83 patients enrolled in the study and to deeply examine 20 (24.10%) patients that developed a new echinococcal cyst. Moreover, the causes at the basis of the onset of a new cyst were analysed, together with a possible correlation with different treatments related to primary infection corresponding to surgery (n=7), albendazole (n=6), PAIR (n=3) and watch and wait (n=4). A possible link with medical treatments of the primary infection was observed in the subjects who underwent surgery or PAIR and a likely correlation attributable to high environmental contamination in subjects managed with drugs or watch and wait was detected. Moreover, our analysis evidenced that patients with a new infection presented a more severe diagnosis along with a major mortality rate. Finally, these data may have an important contribution for an epidemiological point of view concerning the percentage of CE in a specific geographical endemic area, such as Sardinia.

Percutaneous drainage and combined praziquantel-albendazole therapy: a novel approach for the treatment of simple echinococcal liver cysts

Cystic echinococcosis (CE) is a worldwide helminthic zoonosis causing serious disease in humans. The WHO Informal Working Group on Echinococcosis recommends a stage-specific treatment approach of hepatic CE that facilitates the decision on what therapy option is most appropriate. Percutaneous aspiration, instillation of a scolicide, e.g., ethanol or hypertonic saline, and subsequent re-aspiration (PAIR) have been advocated for treating medium-size unilocular WHO-stage CE1 cysts. PAIR can pose a risk of toxic cholangitis because of spillage of ethanol in the case of a cysto-biliary fistula or of life-threatening hypernatriaemia when hypertonic saline is used. The purpose of our study is to develop an alternative, safe, minimally invasive method to treat CE1 cysts, avoiding the use of toxic topic scolicides.We opt for percutaneous drainage (PD) in four patients: the intrahepatic drainage catheter is placed under CT-fluoroscopy, intracystic fluid is aspirated, and the viability of intracystic echinococcal protoscolices is assessed microscopically. Oral praziquantel (PZQ) is added to albendazole (ABZ) instead of using topical scolicidals.Protoscolices degenerate within 5 to 10 days after PZQ co-medication at a cumulative dosage of 250 to 335 mg/kg, and the cysts collapse. The cysts degenerate, and no sign of spillage nor relapse is observed in the follow-up time of up to 24 months post-intervention.In conclusion, PD combined with oral PZQ under ABZ coverage is preferable to PAIR in patients with unilocular echinococcal cysts.

Proton Nuclear Magnetic Resonance (1H NMR) Metabolomics Study in Serum, Urine, and Cystic Fluid for Differentiating Fertility and Staging of Intra-abdominal Hydatid Cyst in Adults

Background

Cystic echinococcosis (CE) is a parasitic zoonosis caused by the tapeworm Echinococcus granulosus. Over the past few years, a lot of research has been done on liver illnesses using metabolomics techniques to identify biomarkers which could identify the diseases in its early stages. The present study was done to explore biomarkers in serum, urine, and cystic fluid which would help in differentiating, staging, and assessing fertility of intra-abdominal hydatid cyst by using proton nuclear magnetic resonance (1H NMR) metabolomics.

Materials and methods

In the study, 28 subjects (16 cases and 12 controls) were enrolled. Staging of hydatid cysts was performed using ultrasonography. In patients complying with case and control definition, blood, urine, and cystic fluid were collected for complete blood count, urine culture, Echinococcus IgG enzyme-linked immunosorbent assay (ELISA), and metabolomic analysis. The 17, 15, and 11 metabolites in serum, urine, and cystic fluid samples were quantified, respectively, to differentiate between case and control group.

Results

In this study, we observed that there was a significant downregulation of succinate metabolite in urine samples of cases, down-regulation of five metabolites (isoleucine, valine, histidine, tyrosine and formate) and upregulation of alanine in cystic fluid of cases.

Conclusion

Current study demonstrates that metabolomics can be used non-invasively for rapid diagnosis of CE. This is one of the very few studies, which used 1H NMR spectroscopy, to analyze the profile of metabolites in serum, urine, and cystic fluid in cases of CE and controls.

How to cite this article

Raj N, Pandey A, Roy R, et al. Proton Nuclear Magnetic Resonance (1H NMR) Metabolomics Study in Serum, Urine, and Cystic Fluid for Differentiating Fertility and Staging of Intra-abdominal Hydatid Cyst in Adults. Euroasian J Hepato-Gastroenterol 2024;14(1):30-34.

Echinococcoses - A Primer for Radiologists

BACKGROUND

Cystic (CE) and alveolar (AE) echinococcoses are zoonotic parasitoses that may pose diagnostic problems due to their relative rarity in Middle Europe.

METHODS

Based on a recent literature search and the observation of casuistics from a national echinococcosis treatment center, epidemiological, radiological, and therapeutic fundamentals are presented and important differences between AE and CE are discussed.

RESULTS AND CONCLUSION

AE and CE must be regarded as completely different diseases, which differ from each other in every significant aspect. This applies not only to the epidemiological background of the patients but also to the biology of the diseases and their respective imaging features.

KEY POINTS

· AE and CE are very distinct from one another and must be considered separately.. · AE is endemic in Middle Europe and is known as malignant parasitosis due to its destructive growth form.. · CE is primarily seen in Middle Europe in individuals with migration background and has a rather benign character..

CITATION FORMAT

· Weber TF, Mokry T, Stojkovic M. Die Echinokokkosen - Einblicke aus Sicht der Radiologie. Fortschr Röntgenstr 2023; 195: 1106 - 1121.

Watch-and-wait approach for inactive echinococcal cysts: scoping review update since the issue of the WHO-IWGE Expert Consensus and current perspectives

PURPOSE OF REVIEW

This work aims to provide an update of knowledge on the evolution of inactive cystic echinococcosis (CE) cysts (CE4-CE5) managed by 'watch-and-wait', by means of a scoping review of the literature published after the publication of the WHO-IWGE (Informal Working Group on Echinococcosis) Expert Consensus document in 2010.

RECENT FINDINGS

A total of 31 articles were included. Population ultrasound-based studies showed that spontaneously inactivated CE cysts represent 50.2% (95% confidence interval 38.7-61.8) of all detected untreated CE cysts, and that the prevalence of CE4-CE5 cysts tends to increase with age. Four longitudinal population-based studies showed that CE cysts naturally tend to evolve towards inactivation and that spontaneously inactivated cysts reactivate in a minority of cases. This was confirmed by four hospital-based studies, showing that spontaneously inactivated cysts reactivate rarely, while rate of reactivation is higher if inactivity was obtained posttreatment. It was not possible to drive conclusions on any difference in the clinical course of infection in immunocompromised or pregnant patients.

SUMMARY

CE cysts tend to evolve spontaneously to inactivation over time. The published literature supports the safety of the watch-and-wait approach for inactive cysts, sparing treatment to a substantial proportion of asymptomatic patients. A regular follow-up with ultrasound of all inactive cysts is required to detect reactivations.

'No cyst, no echinococcosis': a scoping review update on the diagnosis of cystic echinococcosis after the issue of the WHO-IWGE Expert Consensus and current perspectives

PURPOSE OF REVIEW

In 2010, the WHO-Informal Working Group on Echinococcosis (IWGE) published an Expert Consensus on the diagnosis and treatment of echinococcal infections. We provide an update on the diagnosis of cystic echinococcosis through a scoping review of the literature published after the release of the WHO-IWGE document.

RECENT FINDINGS

Ultrasound accurately and reliably depicts the pathognomonic signs of cystic echinococcosis (CE) stages compared with other imaging techniques. Among these, T2-wighted MRI is to be preferred to computed tomography, which has poor performance for the etiological diagnosis of CE. A negative serology cannot exclude the diagnosis of CE, while a positive serology, applied after the visualization of a CE-compatible lesion, may confirm a CE diagnosis. Serology alone must not be used to define 'CE' nor as 'screening' tool for infection. Other imaging and laboratory techniques did not show clinically applicable performances.

SUMMARY

In the absence of a focal lesion compatible with a CE cyst, no diagnosis of CE should be attempted. There is urgent need to achieve univocal CE case definitions and consensus diagnostic algorithm, as well as standardization of diagnostic methods and issue of a Target Product Profile of CE diagnostics, as advocated by the WHO in the 2021-2030 roadmap for neglected tropical diseases (NTDs).

Pitsilka M, Magouliotis D, Zacharoulis D. New Energy Devices in the Treatment of Cystic Echinococcosis

Treatment of cystic echinococcosis of the liver still remains a debatable subject. The method of choice should aim for the total elimination of the parasite with minimum morbidity and mortality. Different approaches have been proposed. Medical treatment as a monotherapy has been abandoned due to the high chances of recurrence and is mostly used as an adjuvant to surgery or minimally invasive methods. Surgical methods are divided into conservative ones, which include cystectomy and partial pericystectomy, and radical ones, total pericystectomy and hepatectomy. Radical procedures are correlated with lower complication and recurrence rates and, therefore, should be attempted when indications are present. On the other hand, conservative surgery can be the first option in endemic areas, performed by non-specialized general surgeons. The development of laparoscopic techniques made their use a possible alternative approach in selected cases. The use of percutaneous treatments is also quite widespread due to their minimally invasive nature. New energy devices seem to play a significant role in the treatment of cystic echinococcosis, although more studies are needed to establish their efficacy. Observation without intervention is an option for inactive uncomplicated cysts.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part I - Cystic lesions

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the first part of the guideline, concerning the characterization of focal hepatic lesions detected by ultrasound, and the diagnosis and clinical management of simple and parasitic hepatic cysts, and of polycystic liver disease.

Turkish HPB Surgery Association consensus report on hepatic cystic Echinococcosis (HCE)

OBJECTIVES

Cystic Echinococcosis (CE) is one of the important problems of the Eurasian region. We aimed to prepare a consensus report in order to update the treatment approaches of this disease. This study was conducted by Turkish HPB Surgery Association.

MATERIAL AND METHODS

This study was conducted with the modified Delphi model. For this purpose, we conducted a three-stage consensus-building approach.

RESULTS

Six topics, including diagnosis, medical treatment, percutaneous treatment, surgical treatment, management of complications and posttreatment follow-up and recurrences in HCE were discussed.

CONCLUSION

The expert panel made recommendations for every topic.

Progress in diagnosis and treatment of hepatic cystic echinococcosis in children

Hepatic cystic echinococcosis is a zoonotic parasitic disease caused by infection with Echinococcus granulosus that is widely distributed worldwide. As a special population, children are the key population for the prevention and treatment of echinococcosis, and are also the key target for monitoring in large-scale prevention and treatment. The symptoms of hepatic cystic echinococcosis in children are atypical and easy to be misdiagnosed, and irregular treatment can easily lead to recurrence or even death. This paper provides a review of the diagnosis and treatment modalities for hepatic cystic echinococcosis in children.

Comparison of the multi-epitope recombinant antigen DIPOL and hydatid fluid for the diagnosis of patients with cystic echinococcosis

The use of serological tests containing multiple immunodominant antigens rather than single antigens have the potential to improve the diagnostic performance in Cystic Echinococcoses (CE) as a complement tool to clear the inconclusive imaging data. Here, we comparatively evaluated the diagnostic value of Hydatid Fluid (HF) and the recently described recombinant multi-epitope antigen DIPOL in IgG-ELISA in a clinically defined cohort of CE patients. The serum samples from 149 CE patients were collected just before surgical or Percutaneous- Aspiration- Injection- Reaspiration (PAIR) procedures. Additionally, serum samples of patients with other parasitic infections (n=49) and healthy individuals (n=21) were also included in the study as controls. To investigate the association between the genotype of the parasite and DIPOL, cyst materials from 20 CE patients were sequenced. In terms of overall sensitivity, HF was higher than DIPOL (82.55%,78.52%, respectively). However, while the sensitivity of HF was higher than DIPOL in patients with active and transitional cysts (83.3%, 75.4%, respectively), sensitivity of DIPOL in inactive cysts was higher compared to HF (95.6%, 78.3%, respectively). The sensitivity of DIPOL depending on cyst stage was statistically significant (P= 0.041). In terms of specificity, DIPOL was found to be better than HF (97.71%, 91.43%, respectively). By genotyping, the majority of 20 patients showed G1 genotype (80%). All patients harboring G3 and G1/G3 cyst genotypes were positive with both antigens, while 87.5% of patients with G1 genotype were seropositive with HF and 75% with DIPOL. The overall sensitivity and high specificity of DIPOL suggest that this recombinant protein containing immunodominant epitopes is a potential substitute for the HF by serological tests for the diagnosis of CE.

Is Surgery for Hepatic Echinococcosis Appropriate in a Low-Volume Center?

Background: Cystic echinococcosis is a parasitic disease that develops in endemic areas due to the transmission of Echinococcus granulosus. The liver is the organ most affected. The most frequent symptoms include pain, palpable mass, jaundice, and fever. Diagnosis is based on epidemiologic history, examination, imaging, and serologic tests. Patients and Methods: We conducted a retrospective study of patients with hepatic echinococcosis diagnosed in our center. We collected data from our patients regarding personal history, cyst characteristics, surgery performed, and post-operative complications. Results: Sixteen patients were diagnosed with hepatic echinococcosis, 11 of whom underwent surgery. We found multiple cysts in six patients (37.5%) and a single cyst in 10 (62.5%). In 14 patients the cysts were found only in the right hepatic lobe (87.5%) and in two patients they were found in both lobes (12.5%). Segment 4 was affected in seven cases. The sizes ranged from 2.7 to 20 cm. Endoscopic retrograde cholangiopancreatography was prior to surgery in five patients. The interventions performed were partial cyst-pericystectomies in eight patients, a total cyst-pericystectomy in one case, and drains were placed in two cases of rupture. Post-operative fistulas were evident in five patients, four of which were closed. The fifth, which occurred after emergency surgery for rupture of the cyst, has maintained suppuration. The mean follow-up was 3.5 years. There was no post-operative mortality or recurrence to date. Conclusions: We can state that center without highly specialized hepato-biliary surgery units can assume the surgery of hydatid liver cysts excluding those with well-defined characteristics. The establishment of recommendations for the referral of patients with complex hydatid cysts may help in the optimal management of this pathology.

Prospective collection of clinical data on cystic echinococcosis: experience with the European Registry of Cystic Echinococcosis in Pavia, Italy

BACKGROUND

Cystic echinococcosis (CE) is a chronic, complex and neglected infection that may cause serious disease in humans. Given its peculiar epidemiologic and clinical features, collection of clinical data is challenging. Notification systems, when available, fail to record important clinical features, available data are mostly retrospectively collected and no prospectively enrolled uniform surveillance systems exist. The European Register of Cystic Echinococcosis database (ERCE) is the first systematic attempt to address these issues.

METHODS

Here, we describe the demographics and clinical characteristics of 436 patients who accessed the CE clinic at the University of Pavia-San Matteo Hospital Foundation, in Pavia, Italy, from March 2012 to February 2020.

RESULTS

Overall, 436 patients, consisting of 204 (46.8%) males and 232 (53.2%) females were enrolled; the mean age at enrollment was 50 (range 4-88) y. Of the 436 patients, 248 (56.9%) were born in Italy while 188 (43.1%) were foreign-born. In total, 638 CE cysts were counted, most of them in the CE4 (230; 36.1%) and CE3b (131; 20.5%) stages.

CONCLUSIONS

This is the largest cohort of CE patients with detailed clinical and demographic data published to date. We strongly encourage colleagues caring for CE patients in the European Union to join the ERCE.

Percutaneous Versus Surgical Interventions for Hepatic Cystic Echinococcosis: A Systematic Review and Meta-Analysis

Purpose

This systematic review and meta-analysis summarises the current literature on invasive treatment options of cystic hepatic echinococcosis (CE), comparing percutaneous radiological interventions to surgery, still the cornerstone of treatment in many countries.

Methods

A literature search was conducted in Medline and EMBASE databases (PROSPERO registration number: CRD42019126150). The primary outcome was recurrence of cysts after treatment. Secondary outcomes were complications, duration of hospitalisation, mortality and treatment conversion.

Results

The number of eligible prospective studies, in particular RCTs, was limited. In the four included studies, only conventional surgery is compared directly to percutaneous techniques. From the available data, in terms of recurrence, percutaneous treatment of hydatid cysts is non-inferior to open surgery. With regard to complications and length of hospital stay, outcomes favour percutaneous therapy.

Conclusion

Although evidence from prospective research is small, percutaneous treatment in CE is an effective, safe and less invasive alternative to surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00270-021-02911-4.

Parasites of the liver - epidemiology, diagnosis and clinical management in the European context

Parasites in the liver cause significant global morbidity and mortality, as they can lead to recurrent cholangitis, cirrhosis, liver failure and cancer. Due to climate change and globalisation, their incidence is increasing, especially in Europe. The correct diagnosis of a hepatic parasite is often delayed because clinicians are unfamiliar with respective entities. Therefore, in this review, we aim to provide clinicians with a comprehensive clinical picture of hepatic parasites and to bring these neglected parasitic liver diseases to the wider attention of hepatology stakeholders in Europe and around the world.

Endocystectomy as a conservative surgical treatment for hepatic cystic echinococcosis: A systematic review with single-arm meta-analysis

BACKGROUND

In patients with hepatic cystic echinococcosis (CE), treatment effectiveness, outcomes, complications, and recurrence rate are controversial. Endocystectomy is a conservative surgical approach that adequately removes cyst contents without loss of parenchyma. This conservative procedure has been modified in several ways to prevent complications and to improve surgical outcomes. This systematic review aimed to evaluate the intraoperative and postoperative complications of endocysectomy for hepatic CE as well as the hepatic CE recurrence rate following endocystectomy.

METHODS

A systematic search was made for all studies reporting endocystectomy to manage hepatic CE in PubMed, Web of Science, and Cochrane CENTRAL databases. Study quality was assessed using the methodological index for non-randomized studies (MINORS) criteria and the Cochrane revised tool to assess risk of bias in randomized trials (RoB2). The random-effects model was used for meta-analysis and the arscine-transformed proportions were used to determine complication-, mortality-, and recurrence rates. This study is registered with PROSPERO (number CRD42020181732).

RESULTS

Of 3,930 retrieved articles, 54 studies reporting on 4,058 patients were included. Among studies reporting preoperative anthelmintic treatment (31 studies), albendazole was administered in all of them. Complications were reported in 19.4% (95% CI: 15.9-23.2; I2 = 84%; p-value <0.001) of the patients; biliary leakage (10.1%; 95% CI: 7.5-13.1; I2 = 81%; p-value <0.001) and wound infection (6.6%; 95% CI: 4.6-9; I2 = 27%; p-value = 0.17) were the most common complications. The post-endocystectomy mortality rate was 1.2% (95% CI: 0.8-1.8; I2 = 21%; p-value = 0.15) and the recurrence rate was 4.8% (95% CI: 3.1-6.8; I2 = 87%; p-value <0.001). Thirty-nine studies (88.7%) had a mean follow-up of more than one year after endocystectomy, and only 14 studies (31.8%) had a follow-up of more than five years.

CONCLUSION

Endocystectomy is a conservative and feasible surgical approach. Despite previous disencouraging experiences, our results suggest that endocystectomy is associated with low mortality and recurrence.

Proteomic analysis of plasma exosomes from Cystic Echinococcosis patients provides in vivo support for distinct immune response profiles in active vs inactive infection and suggests potential biomarkers

The reference diagnostic method of human abdominal Cystic Echinococcosis (CE) is imaging, particularly ultrasound, supported by serology when imaging is inconclusive. However, current diagnostic tools are neither optimal nor widely available. The availability of a test detecting circulating biomarkers would considerably improve CE diagnosis and cyst staging (active vs inactive), as well as treatments and follow-up of patients. Exosomes are extracellular vesicles involved in intercellular communication, including immune system responses, and are a recognized source of biomarkers. With the aim of identifying potential biomarkers, plasma pools from patients infected by active or inactive CE, as well as from control subjects, were processed to isolate exosomes for proteomic label-free quantitative analysis. Results were statistically processed and subjected to bioinformatics analysis to define distinct features associated with parasite viability. First, a few parasite proteins were identified that were specifically associated with either active or inactive CE, which represent potential biomarkers to be validated in further studies. Second, numerous identified proteins of human origin were common to active and inactive CE, confirming an overlap of several immune response pathways. However, a subset of human proteins specific to either active or inactive CE, and central in the respective protein-protein interaction networks, were identified. These include the Src family kinases Src and Lyn, and the immune-suppressive cytokine TGF-β in active CE, and Cdc42 in inactive CE. The Src and Lyn Kinases were confirmed as potential markers of active CE in totally independent plasma pools. In addition, insights were obtained on immune response profiles: largely consistent with previous evidence, our observations hint to a Th1/Th2/regulatory immune environment in patients with active CE and a Th1/inflammatory environment with a component of the wound healing response in the presence of inactive CE. Of note, our results were obtained for the first time from the analysis of samples obtained in vivo from a well-characterized, large cohort of human subjects.

The European Register of Cystic Echinococcosis, ERCE: state-of-the-art five years after its launch

BACKGROUND

The real burden of human cystic echinococcosis (CE) remains elusive, due to the peculiar characteristics of the disease and the heterogeneous and incomplete data recording of clinical cases. Furthermore, official notification systems do not collect pivotal clinical information, which would allow the comparison of different treatment outcomes, and thus circumvent the difficulty of implementing clinical trials for CE. The Italian Register of CE (RIEC) was launched in 2012 and expanded in 2014 into the European Register of CE (ERCE). The primary aim of the ERCE was to highlight the magnitude of CE underreporting, through the recording of cases that were not captured by official records. We present an overview of data collated in the ERCE and discuss its future, five years after its inception.

METHODS

The ERCE database was explored on March 31st 2019; data concerning participating centres and registered cases were descriptively analysed.

RESULTS

Forty-four centres from 15 countries (7 non-European) were affiliated to the ERCE. Thirty-four centres (77%) registered at least one patient; of these, 18 (53%) recorded at least one visit within the past 18 months. A total of 2097 patients were registered, 19.9% of whom were immigrants. Cyst characteristics were reported for at least one cyst at least in one visit in 1643 (78.3%) patients, and cyst staging was used by 27 centres. In total, 3386 cysts were recorded at first registration; mostly located in the liver (75.5%). Data concerning clinical management could be analysed for 920 "cyst stage-location-management" observations, showing great heterogeneity in the implementation of the stage-specific management approach recommended by the WHO.

CONCLUSIONS

The ERCE achieved its goal in showing that CE is a relevant but neglected public health problem in Europe and beyond, since a proportion of patients reaching medical attention are not captured by official notification systems. The ERCE may provide a valuable starting platform to complement hospital-derived data, to obtain a better picture of the epidemiology of clinical CE, and to collect clinical data for the issue of evidence-based recommendations. The ERCE will be expanded into the International Register of CE (IRCE) and restructured aiming to overcome its current criticalities and fulfil these aims.

Sound Around the World: Ultrasound for Tropical Diseases

Ultrasound for diagnosis and staging of schistosomiasis and echinococcosis have paved the way over the past several decades for the application of ultrasound in tropical diseases. Until recently, the size and cost of ultrasound systems limited the application in low-resource settings. The increase in portable ultrasound systems has given more clinicians access to ultrasound, and clinically based protocols for the care of patients have emerged, such as focused assessment with sonography for HIV/TB and tropical cardiac ultrasound. This article explores the history and current use of ultrasound in these diseases and highlights their application in the care of patients.

Structural and Immunodiagnostic Characterization of Synthetic Antigen B Subunits From Echinococcus granulosus and Their Evaluation as Target Antigens for Cyst Viability Assessment

Background

Several tools have been proposed for serodiagnosis of cystic echinococcosis (CE), but none seems promising for cyst viability assessment. Antigens with stage-specific diagnostic value have been described, but few studies with well-characterized antigens and human serum samples have been performed. Antigen B (AgB) proteoforms hold promise as markers of viability, due to their differential stage-related expression and immunoreactivity.

Methods

Four AgB subunits (AgB1, AgB2, AgB3, AgB4) were synthesized and structurally characterized. Based on the preliminary evaluation of the subunits by western immunoblotting and enzyme-linked immunosorbent assay (ELISA), AgB1 and AgB2 were further tested in two ELISA setups and extensively validated on 422 human serum samples.

Results

All subunits showed a high degree of spontaneous oligomerization. Interacting residues within oligomers were identified, showing that both the N-terminal and C-terminal of each subunit are involved in homo-oligomer contact interfaces. No hetero-oligomer was identified. AgB1 and AgB2 ELISAs revealed different sensitivities relative to cyst stage. Of note, besides high specificity (97.2%), AgB1 revealed a higher sensitivity for active-transitional cysts (100% for CE1, 77.8% for CE2, 81.5% for CE3a, and 86.3% for CE3b) than for inactive cysts (41.7% for CE4 and 11.1% for CE5) and postsurgical patients (44%). Interestingly, 19 of 20 patients with spontaneously inactive cysts and 6 of 9 treated with albendazole >5 years earlier were negative on the AgB1 assay.

Conclusions

The structural characterization of subunits provides insights into the synthetic antigen conformation. The stage-related sensitivity of synthetic AgB1 holds promise as part of a multiantigen setting and deserves further longitudinal evaluation as marker of cyst viability.

Case Report: Percutaneous Treatment of Multiple Echinococcal Cysts Presenting as Abdominal Palpable Mass

We report the case of an adolescent Moroccan girl with abdominal pain and palpable mass in the upper right side of the abdomen. In the emergency department, an abdominal ultrasound showed hepatomegaly and eight active liver cysts, compatible with cystic echinococcosis. Serology for Echinococcus granulosus confirmed the diagnosis. Other sites of localization were excluded. Treatment involved albendazole combined with puncture, aspiration, injection, re-aspiration, performed only for the most medial cysts. Periodical follow-up with abdominal ultrasound and with abdominal magnetic resonance imaging showed a progressive involution of all cysts. The treatment with albendazole was stopped after, overall, 6 months, and monthly ultrasound scan were planned as follow-up. In case of hepatic cysts, E. granulosus should be excluded, especially in children from endemic countries. A multidisciplinary approach with pediatric infectious disease specialists, radiologists, and surgeons is fundamental for disease management.

Clinical management of cystic echinococcosis: state of the art and perspectives

PURPOSE OF REVIEW

This review draws attention to patients with cystic echinococcosis migrating from highly endemic to non-endemic countries with limited experience in cystic echinococcosis management, to ultrasound-based cyst staging, and to the WHO cyst classification as a powerful, to date underused tool to triage patients into the four currently available treatment modalities.

RECENT FINDINGS

In non- and low-prevalence countries, cystic echinococcosis is often misclassified. Differential diagnoses, such as simple cysts and other benign and malignant space-occupying lesions, have similar appearances on imaging. Serology is confirmatory but often disappointing due to sensitivity and specificity problems. There is increasing confidence in assigning uncomplicated cystic echinococcosis cysts to the four treatment modalities [drug treatment (benzimidazoles), percutaneous methods, surgery, watch and wait] on the basis of cyst stage (WHO cyst classification), size and location. However, current best practice is still not widely implemented outside cystic echinococcosis treatment centres, and further consolidation is needed by well-designed clinical trials. Recently published long-term follow-up studies have shown that patients with inactive cyst stages CE4 and CE5 benefit, especially since they do not need any treatment at all if they have not received prior benzimidazole or percutaneous therapy. Instead, cysts that have reached cyst stages CE4 and CE5 through drug treatment do need careful follow-up as they often relapse. Surgical procedures in which the cysts are opened and percutaneous approaches require very careful control of cyst content spillage to the peritoneum, pleura and intravascularly to prevent dissemination - a still too often neglected issue with severe consequences for patients.

SUMMARY

Though a neglected disease with predominantly expert-opinion-based treatment strategies, cystic echinococcosis patients can greatly benefit from interdisciplinary management in cystic echinococcosis treatment centres and cyst-stage-based assignment of treatment modalities. Increased suspicion for cystic echinococcosis in migrants from endemic to non-endemic countries is urgently needed at the current level of global mobility.

Standardized endocystectomy technique for surgical treatment of uncomplicated hepatic cystic echinococcosis

BACKGROUND

Two surgical options are available for cystic echinococcosis (CE). The two principal approaches are radical (resection of the cyst) and conservative (evacuation of the cyst content and partial removal of the cyst capsule). Here, we describe a standardized endocystectomy technique for hepatic echinococcosis.

SUBJECTS AND METHODS

Twenty-one patients (male/female: 4/3; median age: 28 years) with uncomplicated, isolated hepatic CE (cyst stages WHO CE1, 2, 3a, and 3b) that were treated with the standardized endocystectomy described in this paper. Before the operation and during the follow-up period (mean: 33.8 months, median: 24 months), patients underwent clinical and sonographical and/or magnetic resonance imaging assessment during regular visits managed by an interdisciplinary team.

RESULTS

Forty-seven cysts were treated with the standardized endocystectomy technique. The median number of cysts per patient was two (range: 1-8). Nine patients (43%) had a single cystic lesion. The median operation time was 165 minutes and the median intraoperative bleeding volume was 200 mL. The median hospital stay was nine days (range: 6-28 days). Morbidity (Clavien-Dindo III) occurred in four patients (19%). No mortality and no recurrence were found during the median follow-up time of 24 months.

CONCLUSIONS

The standardized endocystectomy technique presented is a safe procedure with acceptable morbidity, no mortality, and without recurrences in our patient series. Important components of our CE management are interdisciplinary patient care, adequate diagnostic work-ups, and regular pre- and postoperative visits, including long-term follow-up for early and reliable capture of recurrences.

Should Pediatricians Be Aware of Cystic Echinococcosis? A Literature Review

Among parasitic hepatic cystic lesions, the most common disease is represented by cystic echinococcosis (CE), especially in high endemic countries. European epidemiology of CE in children is difficult to assess because of under-reporting but is increasing, because of high immigration flows from endemic countries and an increased awareness. Hydatidosis can be localized in every part of the body. The liver and lungs are the most common localizations in both children and adults. Multiorgan involvement is rarely reported in children. Different tests are available. Usually the sensitivity of serological screening tests is variable, ranging between 60% and 90%. The immunoblot assay is used as a confirmatory test because of its higher sensitivity and specificity. Radiological tests are the criterion standard for diagnosis of CE, with an ultrasound accuracy of approximately 90%. In case of inactive and uncomplicated cysts the watch-and-wait approach is recommended. Albendazole, currently used for 3 to 6 months consecutively represents the most commonly used drug in children even if there is limited experience in treating children younger than 6 years of age. Percutaneous treatment with the puncture, aspiration, injection, and reaspiration technique is a minimally invasive procedure. Surgery is indicated based on cyst characteristics in case of big cysts with multiple daughter cysts, single superficial cysts at risk of spontaneous or traumatic rupture, cysts related with the biliary tract in which the percutaneous treatment is contraindicated, and cysts compressing related structures.

Severe chest allodynia as an unusual first presentation of hydatid disease: a case report

Background

Cystic echinococcosis (CE) is a worldwide zoonosis and the liver is the most commonly affected organ. Clinical manifestations range from completely asymptomatic cysts to a potential lethal cyst rupture and anaphylaxis.

Case presentation

Severe chest allodynia was an unusual clinical presentation of hepatic cyst rupture in the retroperitoneal space, without any other specific symptoms. CE diagnosis was confirmed by computed tomography scan and magnetic resonance. The patient underwent hepatectomy with complete resolution of the neuropathic pain.

Conclusions

Retroperitoneal hydatid cyst rupture is a rare event and its clinical manifestation may mimic other chest neuropathies.

Evaluation of the recombinant antigens B2t and 2B2t, compared with hydatid fluid, in IgG-ELISA and immunostrips for the diagnosis and follow up of CE patients

Cystic echinococcosis (CE) is one of the most widespread helminthic zoonoses and is caused by the tapeworm Echinococcus granulosus complex. CE diagnosis and monitoring primarily rely on imaging techniques, complemented by serology. This is usually approached by the detection of IgG antibodies against hydatid fluid (HF), but the use of this heterogeneous antigenic mixture results in a variable percentage of false positive and negative results, and has shown to be useless for follow-up due to the long persistence of anti-HF antibodies in cured patients. To improve test performances and standardization, a number of recombinant antigens mainly derived from HF have been described, among them the B2t and 2B2t antigens. The performance of these antigens in the diagnosis and follow up of patients with CE has been so far evaluated on a limited number of samples. Here, we evaluated the performances of tests based on B2t and 2B2t recombinant antigens compared to HF in IgG-ELISA and immunochromatography (IC) for the diagnosis and follow-up of patients with CE in a retrospective cohort study. A total of 721 serum samples were collected: 587 from 253 patients with CE diagnosed by ultrasonography (US), 42 from patients with alveolar echinococcosis and 92 from healthy donors from Salamanca (Spain). The highest overall sensitivity was obtained with HF in ELISA (85.5%), followed by IC containing HF and 2B2t-HF (83.0% and 78.2%, respectively). The lowest sensitivity was obtained with B2t and 2B2t in ELISA (51.8%). The highest specificity was obtained with IC containing 2B2t-HF (100%), and the lowest with HF-ELISA (78.0%). The lowest cross-reactivity with sera from patients with alveolar echinococcosis was detected with the recombinant antigens in ELISA (9.5% - 16.7%) and the highest with the HF-IC (64.3%). The results of B2t and 2B2t-ELISA were influenced by cyst stage, as classified by US according to the WHO-Informal Working Group on Echinococcosis (WHO-IWGE), with low sensitivity for inactive (CE4 and CE5) cysts, and by the drug treatment, with higher sensitivity in patients after drug treatment compared with patients not subjected to drug treatment. The two recombinant antigens in ELISA provided promising results for monitoring patients in follow-up, although their use is limited to patients with positive serology against them at the beginning of the follow-up. Potential biological reasons behind the low sensitivity of the recombinant antigens and possible strategies to enhance the performance of CE serology are discussed.

Cystic echinococcosis (CE) is a helminthic zoonosis caused by Echinococcus granulosus sensu lato. CE diagnosis and monitoring is of paramount importance for the clinical management of patients and primarily rely on imaging techniques, complemented by serology. CE serology is usually based on the detection of antibodies against hydatid fluid (HF), but the use of this heterogeneous antigenic mixture shows several drawbacks, including false positive and negative results, unsatisfied predictive values, and long persistence of detectable antibody levels in cured patients. As an alternative, to improve test performances and standardization, several recombinant antigens have been described, but these have been so far evaluated only on a limited number of samples. Here, two recombinant antigens derived from one of the immunodominant HF antigens (antigen B2) have been tested in enzyme-linked immunosorbent assay (ELISA) and in immunochromatographic strips (IC) against 721 serum samples. Although more specific than the HF, the recombinant antigens in ELISA showed low sensitivity for patients with inactive (CE4 and CE5) cysts and for patients not subjected to drug treatment. This limited their use for follow-up, although promising, to those patients with positive serology at the beginning of the follow-up period. These results will aid in the future development of a serological test with enhanced performance in the diagnosis and follow-up of patients with CE.

Patients with cystic echinococcosis in the three national referral centers of Mongolia: A model for CE management assessment

Background

Mongolia is one of the endemic countries for cystic echinococcosis (CE), a zoonotic disease caused by the larval stage of Echinococcus granulosus. The goal of this study is to describe the current clinical management of CE in Mongolia, to capture the distribution of cyst stages of patients treated, and to contrast current practice with WHO-IWGE expert consensus.

Methods

Hospital records of CE patients treated between 2008 and 2015 at the three state hospitals and fulfilling the inclusion criterion ‘discharge diagnosis CE’ (ICD 10 code B.67.0–67.9) were reviewed. Demographical, geographical, clinical and ultrasonography (US) data were extracted and analyzed. The annual surgical incidence was estimated. The digital copies of US cyst images were independently staged by three international experts following the WHO CE cyst classification to determine the proportions of patients which ideally would have been assigned to the WHO recommended treatment modalities surgery, percutaneous, medical (benzimidazole) treatment and watch & wait.

Results

A total of 290 patient records fulfilled the inclusion criteria of the study. 45.7% of patients were below 15 years of age. 73.7% of CE cysts were located in abdominal organs, predominantly liver. US images of 84 patients were staged and assessed for interrater-agreement. The average raw agreement was 77.2%. Unweighted Kappa coefficient and weighted Kappa was 0.57 and 0.59, respectively. Mean proportions of images judged as stages CE1, CE2, CE3a, CE3b, CE4 and CL were 0.59, 0.01, 0.19, 0.08, 0.03 and 0.11, respectively. 40 cysts met the inclusion criteria of treatment modality analysis. The mean proportions of cases with a single cyst assigned to medical, percutaneous treatment, surgery and watch & wait were 52.5% (95% CI 42–65), 25.8% (95% CI 15–30), 5.1% (95% CI 0–10) and 3.3% (95% CI 0–10), respectively. 13.3% (95% CI 5–25) of cysts were staged as CL and therefore assigned to further diagnostic requirement.

Conclusion

WHO CE cyst classification and WHO-IWGE expert consensus on clinical CE management is not implemented in Mongolia. This results in exclusively surgical treatment, an unnecessary high risk approach for the majority of patients who could receive medical, percutaneous treatment or observation (watch & wait). Introduction of WHO-IWGE expert consensus and training in ultrasound CE cyst staging would be highly beneficial for patients and the health care services.

Cystic Echinococcosis (CE) is a zoonotic disease, commonly known as dog tapeworm. The disease is distributed globally and predominantly affects rural populations with limited access to health care. Following the expert consensus of the WHO-Informal Working Group on Echinococcosis (WHO—IWGE) patients with uncomplicated cysts are assigned on the basis of WHO cyst classification to four treatment modalities: medical (benzimidazoles), percutaneous, surgical treatment, and ‘watch & wait’. In Mongolia, one third of the population practices nomadic farming. These populations are heavily affected by CE. However, cyst staging and WHO-IWGE recommendations are not implemented and patients referred to the three national treatment centres receive surgical treatment. This exposes a large proportion of patients to an unnecessary high risk approach who could be treated–depending on cyst stage—with benzimidazoles, percutaneously or observed (watch & wait). We reviewed the hospital records of patients with CE and admitted between 2008 and 2015 to the three national CE treatment centres, retrospectively staged the cysts and assigned the patients to the four WHO-IWGE recommended treatment modalities. We found a high proportion of patients in the study population who would have most likely benefitted from non-surgical treatment options.

Watch and Wait Approach for Inactive Echinococcal Cyst of the Liver: An Update

Human cystic echinococcosis (CE) is a chronic, complex and neglected infection causing severe disease in humans. Hepatic CE cysts are detected and classified mainly by using ultrasound. Expert opinion and published data suggest that uncomplicated inactive liver cysts do not require treatment and only need to be monitored over time ("Watch and Wait"). Here we update our findings as published in 2014 on the "Watch and Wait" approach applied to inactive, asymptomatic cysts of the liver to keep the medical community informed. Clinical data of patients who accessed the World Health Organization Collaborating Center for CE at the University of Pavia-San Matteo Hospital Foundation from January 1991 to October 2017 were analyzed. Inclusion criteria were presence of one or more inactive uncomplicated cysts in the liver (CE4 or CE5), without any history of previous treatment, and an ultrasound-based follow-up of at least 24 months. Fifty-three patients with 66 inactive cysts fulfilled the inclusion criteria. Of these, 11 patients are newly described here; 37 were part of our previously described cohort and the follow-up for 17 of them was further extended; and five were excluded from the previously published analysis as their follow-up was too short, but could be included now. Without the need for treatment and without development of complications, 98.5% of cysts remained inactive over time. In only one patient (1.9% of patients), a reactivation of one cyst (1.5% of cysts) was observed.

Prevalence of abdominal cystic echinococcosis in rural Bulgaria, Romania, and Turkey: a cross-sectional, ultrasound-based, population study from the HERACLES project

BACKGROUND

Cystic echinococcosis is a neglected zoonotic infection that is distributed worldwide and prioritised by WHO for control efforts. The burden of human cystic echinococcosis is poorly understood in most endemic regions, including eastern Europe. We aimed to estimate the prevalence of abdominal cystic echinococcosis in rural areas of Bulgaria, Romania, and Turkey.

METHODS

We did a cross-sectional ultrasound-based survey that recruited volunteers from 50 villages in rural areas of Bulgaria, Romania, and Turkey. These villages were in provinces with annual hospital incidence of cystic echinococcosis within the mid-range for the respective countries. All people who attended a session were allowed to participate if they agreed to be screened. Abdominal ultrasound screening sessions were hosted in public community structures such as community halls, primary health-care centres, schools, and mosques. Lesions were classified using an adapted WHO classification. We reported the prevalence of abdominal cystic echinococcosis adjusted by sex and age through direct standardisation, using the country's rural population as a reference.

FINDINGS

From July 1, 2014, to Aug 3, 2015, 24 693 individuals presented to screening sessions and 24 687 underwent ultrasound screening. We excluded a further six indivduals due to missing data, leaving 24 681 people in our analysis. Abdominal cystic echinococcosis was detected in 31 of 8602 people screened in Bulgaria, 35 of 7461 screened in Romania, and 53 of 8618 screened in Turkey. The age and sex adjusted prevalence of abdominal cystic echinococcosis was 0·41% (95% CI 0·29-0·58) in Bulgaria, 0·41% (0·26-0·65) in Romania, and 0·59% (0·19-1·85) in Turkey. Active cysts were found in people of all ages, including children, and in all investigated provinces.

INTERPRETATION

Our results provide population-based estimates of the prevalence of abdominal cystic echinococcosis. These findings should be useful to support the planning of cost-effective interventions, supporting the WHO roadmap for cystic echinococcosis control.

FUNDING

European Union Seventh Framework Programme.