Metabolic viability assessment of cystic echinococcosis using high-field 1H MRS of cyst contents

Is there echinococcosis in West Africa? A refugee from Niger with a liver cyst

BACKGROUND

Italy is presently facing an increase in immigration from sub-Saharan Africa through the Mediterranean Sea. Case reports of human cystic echinococcosis (CE) have been reported from most sub-Saharan countries. Therefore, an increase in the number of patients with CE coming from these areas in the Italian and European centers for infectious diseases is expected. Unfortunately, the epidemiology of CE in sub-Saharan countries is poorly known, which makes clinical suspicion and diagnosis of such infection difficult in patients coming from these areas.

RESULTS

Here we report a case of hepatic CE in a patient from Niger who arrived in Italy through Libya and visited in a Tropical Medicine referral center in Northern Italy. The parasite was identified molecularly as the G6 "camel" strain of Echinococcus granulosus (E. canadensis). The diagnosis and management of a chronic and clinically complex infection like CE in such situation is difficult. Only 40 cases of CE from Niger have been reported; of these, 75% had extra-hepatic localization. To our knowledge, no strain characterization of human isolates from Niger has been reported so far. The CE cyst of the patient was in CE3a stage, indicating active transmission from the area in which the patient came. However, prevalence data from Niger, and from any other country in West Africa, are almost inexistent.

CONCLUSIONS

We argue that population epidemiology surveys with ultrasound are warranted in Sahelian countries, including Niger. These studies could improve the knowledge of CE epidemiology, provide health authorities with important information for public health interventions targeting this zoonosis, and shed light on any difference between tissue tropism and clinical manifestations caused by the different E. granulosus strains.

Expert Reliability for the World Health Organization Standardized Ultrasound Classification of Cystic Echinococcosis

Cystic echinococcosis (CE), a parasitic zoonosis, results in cyst formation in the viscera. Cyst morphology depends on developmental stage. In 2003, the World Health Organization (WHO) published a standardized ultrasound (US) classification for CE, for use among experts as a standard of comparison. This study examined the reliability of this classification. Eleven international CE and US experts completed an assessment of eight WHO classification images and 88 test images representing cyst stages. Inter- and intraobserver reliability and observer performance were assessed using Fleiss' and Cohen's kappa. Interobserver reliability was moderate for WHO images (κ = 0.600, P < 0.0001) and substantial for test images (κ = 0.644, P < 0.0001), with substantial to almost perfect interobserver reliability for stages with pathognomonic signs (CE1, CE2, and CE3) for WHO (0.618 < κ < 0.904) and test images (0.642 < κ < 0.768). Comparisons of expert performances against the majority classification for each image were significant for WHO (0.413 < κ < 1.000, P < 0.005) and test images (0.718 < κ < 0.905, P < 0.0001); and intraobserver reliability was significant for WHO (0.520 < κ < 1.000, P < 0.005) and test images (0.690 < κ < 0.896, P < 0.0001). Findings demonstrate moderate to substantial interobserver and substantial to almost perfect intraobserver reliability for the WHO classification, with substantial to almost perfect interobserver reliability for pathognomonic stages. This confirms experts' abilities to reliably identify WHO-defined pathognomonic signs of CE, demonstrating that the WHO classification provides a reproducible way of staging CE.

The Echinococcoses: Diagnosis, Clinical Management and Burden of Disease

The echinococcoses are chronic, parasitic diseases that are acquired after ingestion of infective taeniid tapeworm eggs from certain species of the genus Echinococcus. Cystic echinococcosis (CE) occurs worldwide, whereas, alveolar echinococcosis (AE) is restricted to the northern hemisphere, and neotropical echinococcosis (NE) has only been identified in Central and South America. Clinical manifestations and disease courses vary profoundly for the different species of Echinococcus. CE presents as small to large cysts, and has commonly been referred to as 'hydatid disease', or 'hydatidosis'. A structured stage-specific approach to CE management, based on the World Health Organization (WHO) ultrasound classification of liver cysts, is now recommended. Management options include percutaneous sterilization techniques, surgery, drug treatment, a 'watch-and-wait' approach or combinations thereof. In contrast, clinical manifestations associated with AE resemble those of a 'malignant', silently-progressing liver disease, with local tissue infiltration and metastases. Structured care is important for AE management and includes WHO staging, drug therapy and long-term follow-up for at least a decade. NE presents as polycystic or unicystic disease. Clinical characteristics resemble those of AE, and management needs to be structured accordingly. However, to date, only a few hundreds of cases have been reported in the literature. The echinococcoses are often expensive and complicated to treat, and prospective clinical studies are needed to better inform case management decisions.

Laboratory Diagnosis of Echinococcus spp. in Human Patients and Infected Animals

Among the species composing the genus Echinococcus, four species are of human clinical interest. The most prevalent species are Echinococcus granulosus and Echinococcus multilocularis, followed by Echinococcus vogeli and Echinococcus oligarthrus. The first two species cause cystic echinococcosis (CE) and alveolar echinococcosis (AE) respectively. Both diseases have a complex clinical management, in which laboratory diagnosis could be an adjunctive to the imaging techniques. To date, several approaches have been described for the laboratory diagnosis and followup of CE and AE, including antibody, antigen and cytokine detection. All of these approaches are far from being optimal as adjunctive diagnosis particularly for CE, since they do not reach enough sensitivity and/or specificity. A combination of several methods (e.g., antibody and antigen detection) or of several (recombinant) antigens could improve the performance of the adjunctive laboratory methods, although the complexity of echinococcosis and heterogeneity of clinical cases make necessary a deep understanding of the host-parasite relationships and the parasite phenotype at different developmental stages to reach the best diagnostic tool and to make it accepted in clinical practice. Standardization approaches and a deep understanding of the performance of each of the available antigens in the diagnosis of echinococcosis for the different clinical pictures are also needed. The detection of the parasite in definitive hosts is also reviewed in this chapter. Finally, the different methods for the detection of parasite DNA in different analytes and matrices are also reviewed.

Current status of diagnosis and treatment of hepatic echinococcosis

Echinococcus granulosus (E. granulosus) and Echinococcus multilocularis (E. multilocularis) infections are the most common parasitic diseases that affect the liver. The disease course is typically slow and the patients tend to remain asymptomatic for many years. Often the diagnosis is incidental. Right upper quadrant abdominal pain, hepatitis, cholangitis, and anaphylaxis due to dissemination of the cyst are the main presenting symptoms. Ultrasonography is important in diagnosis. The World Health Organization classification, based on ultrasonographic findings, is used for staging of the disease and treatment selection. In addition to the imaging methods, immunological investigations are used to support the diagnosis. The available treatment options for E. granulosus infection include open surgery, percutaneous interventions, and pharmacotherapy. Aggressive surgery is the first-choice treatment for E. multilocularis infection, while pharmacotherapy is used as an adjunct to surgery. Due to a paucity of clinical studies, empirical evidence on the treatment of E. granulosus and E. multilocularis infections is largely lacking; there are no prominent and widely accepted clinical algorithms yet. In this article, we review the diagnosis and treatment of E. granulosus and E. multilocularis infections in the light of recent evidence.

Abdominal Cystic Echinococcosis Treated with Albendazole. A Pediatric Cohort Study

Introduction

Cystic echinococcosis is endemic in Argentina. The standard pharmacological treatment for the disease is albendazole, but surgery is a common alternative. Even though primary infection occurs mainly in the pediatric population, the optimal therapeutic option in pediatrics is not clearly defined and few pediatric cohorts with cystic echinococcosis treated with albendazole have been described to date.

Objective

To describe therapeutic response to albendazole in a cohort of pediatric patients with abdominal cystic echinococcosis.

Population and Methods

Patients (0–18 years old) with abdominal cystic echinococcosis who were treated with albendazole between January 1998 and August 2013. Diagnosis of abdominal cystic echinococcosis was made by ultrasound. All patients received albendazole, 10–15 mg/kg/day. Epidemiological data, symptoms, number, location and outcome of the cysts, serology and treatment received were analyzed. The parameter used to assess treatment response was cyst changes evaluated by ultrasound follow up using the WHO-IWGE classification.

Results

A total of 28 patients (with 46 abdominal cysts) were included in the cohort. Mean age at enrolment was 9.4 years and mean duration of follow-up, 23.8 months. All patients resided in rural areas and had had contact with dogs. The asymptomatic form of the disease was the most common presentation. All patients received albendazole (mean duration: 142.5 days), with low incidence of adverse events. Albendazole had a positive effect on most of the cysts. Surgery was performed in 13 patients.

Conclusion

Treatment with albendazole for uncomplicated cystic echinococcosis cysts is safe and effective, and can potentially reduce the need for surgical intervention.

Diagnostic Accuracy of Antigen 5-Based ELISAs for Human Cystic Echinococcosis

BACKGROUND

Clinical diagnosis and follow up of cystic echinococcosis (CE) are based on imaging complemented by serology. Several immunodiagnostic tests are commercially available, but the development of new tools is still needed to overcome the lack of standardization of the target antigen, generally consisting of a crude extract of Echinococcus granulosus hydatid cyst fluid. In a previous work, we described a chromatographic method for the preparation of a highly enriched Antigen 5 fraction from hydatid cyst fluid. The high reactivity of patient sera against this preparation prompted us to evaluate further this antigen for the serodiagnosis of CE on a larger cohort of samples.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 327 sera from CE patients with heterogeneous conditions for cyst stage, cyst number, organ localization, drug therapy, and surgical intervention, together with 253 sera from healthy controls, were first analyzed by an ELISA based on the Ag5 preparation in two different experimental setups and, in parallel, by a commercial ELISA routinely used in clinical laboratories for CE serodiagnosis. The Ag5 ELISAs revealed different sensitivity (88.3% vs 95.3%) without significant differences in specificity (94.1% vs 92.5%), for the two setups, respectively. Moreover, possible relationships between the Ag5 ELISA absorbance results and clinical variables were investigated. Chi squared test, bivariate logistic regression and multiple regression analyses highlighted differences in the serology reactivity according to pharmacological treatment, cyst activity, and cyst number.

CONCLUSIONS/SIGNIFICANCE

The two Ag5 ELISAs revealed different performances depending on the setup. The good diagnostic sensitivity and the high reliability of the Ag5 preparation method make this antigen a promising candidate for the serodiagnosis of CE. Further studies will be needed to evaluate the ability of our test to provide useful information on specific CE clinical traits.

Comparison of the Diagnostic Accuracy of Three Rapid Tests for the Serodiagnosis of Hepatic Cystic Echinococcosis in Humans

BACKGROUND

The diagnosis of cystic echinococcosis (CE) is based primarily on imaging, in particular with ultrasound for abdominal CE, complemented by serology when imaging results are unclear. In rural endemic areas, where expertise in ultrasound may be scant and conventional serology techniques are unavailable due to lack of laboratory equipment, Rapid Diagnostic Tests (RDTs) are appealing.

METHODOLOGY/PRINCIPAL FINDINGS

We evaluated the diagnostic accuracy of 3 commercial RDTs for the diagnosis of hepatic CE. Sera from 59 patients with single hepatic CE cysts in well-defined ultrasound stages (gold standard) and 25 patients with non-parasitic cysts were analyzed by RDTs VIRapid HYDATIDOSIS (Vircell, Spain), Echinococcus DIGFA (Unibiotest, China), ADAMU-CE (ICST, Japan), and by RIDASCREEN Echinococcus IgG ELISA (R-Biopharm, Germany). Sensitivity, specificity and ROC curves were compared with McNemar and t-test. For VIRapid and DIGFA, correlation between semiquantitative results and ELISA OD values were evaluated by Spearman's coefficient. Reproducibility was assessed on 16 randomly selected sera with Cohen's Kappa coefficient. Sensitivity and Specificity of VIRapid (74%, 96%) and ADAMU-CE (57%, 100%) did not differ from ELISA (69%, 96%) while DIGFA (72%, 72%) did (p = 0.045). ADAMU-CE was significantly less sensitive in the diagnosis of active cysts (p = 0.019) while DIGFA was significantly less specific (p = 0.014) compared to ELISA. All tests were poorly sensitive in diagnosing inactive cysts (33.3% ELISA and ADAMU-CE, 42.8% DIGFA, 47.6% VIRapid). The reproducibility of all RDTs was good-very good. Band intensity of VIRapid and DIGFA correlated with ELISA OD values (r = 0.76 and r = 0.79 respectively, p<0.001).

CONCLUSIONS/SIGNIFICANCE

RDTs may be useful in resource-poor settings to complement ultrasound diagnosis of CE in uncertain cases. VIRapid test appears to perform best among the examined kits, but all tests are poorly sensitive in the presence of inactive cysts, which may pose problems with accurate diagnosis.

Treatment of Hepatic Cystic Echinococcosis in Patients from the Southeastern Rhodope Region of Bulgaria in 2004-2013: Comparison of Current Practices with Expert Recommendations

Cystic echinococcosis (CE) is a clinically complex chronic parasitic disease, management options for which include surgery, percutaneous treatments, and treatment with albendazole (ABZ) for active cysts, and the "Watch-and-Wait" approach for uncomplicated, inactive cysts. We examined, retrospectively, the clinical management of 334 patients with hepatic CE from the southeastern Rhodope region of Bulgaria between 2004 and 2013. Cysts were reclassified according to the World Health Organization Informal Working Group on Echinococcosis (WHO-IWGE) on the basis of ultrasound reports and images. The majority (62.3%) of uncomplicated cysts were CE1, 66% of which were treated surgically. Of all interventions, 5% were performed on inactive uncomplicated CE4-CE5 cysts. About half (47.6%) of these cysts were therefore treated inappropriately, exposing patients to unnecessary treatment-related risks and the health system to unnecessary costs. No management change was observed after the publication of the WHO-IWGE Expert Consensus recommendations in 2010. In Bulgaria, ABZ is still used in interrupted cycles as this is reimbursed, and peri-interventional chemoprophylaxis was not administered in the majority of surgical patients. Efforts are needed to introduce the WHO-IWGE classification and management recommendations and to encourage reception of state-of-the-art practices by public health regulatory bodies to improve patient quality of care and optimization of health resources.

Polyfunctional Specific Response to Echinococcus Granulosus Associates to the Biological Activity of the Cysts

BACKGROUND

Cystic echinococcosis (CE) is a complex disease caused by Echinococcus granulosus (E.granulosus), and its immunophatogenesis is still not clearly defined. A peculiar feature of chronic CE is the coexistence of Th1 and Th2 responses. It has been suggested that Th1 cytokines are related to disease resistance, whereas Th2 cytokines are related to disease susceptibility and chronicity. The aim of this study was to evaluate, by multi-parametric flow cytometry (FACS), the presence of CE specific immune signatures.

METHODOLOGY/PRINCIPAL FINDINGS

We enrolled 54 subjects with suspected CE; 42 of them had a confirmed diagnosis, whereas 12 were classified as NO-CE. Based on the ultrasonography images, CE patients were further categorized as being in "active stages" (25) and "inactive stages" (17). The ability of CD4+ T-cells to produce IFN-γ, IL-2, TNF-α, Th2 cytokines or IL-10 was assessed by FACS on antigen-specific T-cells after overnight stimulation with Antigen B (AgB) of E.granulosus. Cytokine profiles were evaluated in all the enrolled subjects. The results show that none of the NO-CE subjects had a detectable AgB-specific response. Among the CE patients, the frequency and proportions of AgB-specific CD4+ T-cells producing IL-2+TNF-α+Th2+ or TNF-α+Th2+ were significantly increased in the "active stages" group compared to the "inactive stages" group. Moreover, an increased proportion of the total polyfunctional subsets, as triple-and double-functional CD4 T-cells, was found in CE patients with active disease. The response to the mitogen, used as a control stimulus to evaluate the immune competence status, was characterized by the same cytokine subsets in all the subjects enrolled, independent of CE.

CONCLUSIONS

We demonstrate, for the first time to our knowledge, that polyfunctional T-cell subsets as IL-2+TNF-α+Th2+ triple-positive and TNF-α+Th2+ double-positive specific T-cells associate with cyst biological activity. These results contribute to increase knowledge of CE immunophatogenesis and the disease outcome in terms of control and persistence.

Factors Influencing the Serological Response in Hepatic Echinococcus granulosus Infection

Knowledge of variables influencing serology is crucial to evaluate serology results for the diagnosis and clinical management of cystic echinococcosis (CE). We analyzed retrospectively a cohort of patients with hepatic CE followed in our clinic in 2000-2012 to evaluate the influence of several variables on the results of commercial enzyme-linked immunosorbent assay (ELISA) and indirect hemagglutination (IHA) tests. Sera from 171 patients with ≥ 1 hepatic CE cyst, and 90 patients with nonparasitic cysts were analyzed. CE cysts were staged according to the WHO-IWGE classification and grouped by activity. A significant difference in ELISA optical density (OD) values and percentage of positivity was found among CE activity groups and with controls (P < 0.001). The serological response was also influenced by age (P < 0.001) and cyst number (P = 0.003). OD values and cyst size were positively correlated in active cysts (P = 0.001). IHA test showed comparable results. When we analyzed the results of 151 patients followed over time, we found that serology results were significantly influenced by cyst activity, size, number, and treatment ≤ 12 months before serum collection. In conclusion, serological responses as assessed by commercial tests depend on CE cyst activity, size and number, and time from treatment. Clinical studies and clinicians in their practice should take this into account.

Serological Diagnosis and Follow-Up of Human Cystic Echinococcosis: A New Hope for the Future?

Cystic echinococcosis (CE) is an important helminthic zoonotic disease caused by the Echinococcus granulosus complex. In humans, CE is a chronic disease driven by the growth of echinococcal cysts in different organs. Prognosis of this disease depends on multiple factors, including location, number, size, and stage of the cysts, making CE a disease of complex management. CE is usually asymptomatic for years and attracts limited attention from funding organizations and health authorities. For this reason, only experts' recommendations are available but no evidence-based conclusions have been drawn for CE clinical management. One of those pitfalls refers to the lack of evidence to support the use of serological tools for the diagnosis and follow-up of CE patients. In this respect, crude antigens are used to detect specific antibodies in patients, giving rise to false positive results. The advent of molecular techniques allowing the production of recombinant proteins has provided a number of candidate antigens that could overcome the problems associated with the use of crude parasite extracts in the serological assays. In this review, we present the last advances in this field, proposing the use of serology to support cyst stage-specific diagnosis and follow-up.

Non-surgical and non-chemical attempts to treat echinococcosis: do they work?

Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are chronic, complex and neglected diseases. Their treatment depends on a number of factors related to the lesion, setting and patient. We performed a literature review of curative or palliative non-surgical, non-chemical interventions in CE and AE. In CE, some of these techniques, like radiofrequency thermal ablation (RFA), were shelved after initial attempts, while others, such as High-Intensity Focused Ultrasound, appear promising but are still in a pre-clinical phase. In AE, RFA has never been tested, however, radiotherapy or heavy-ion therapies have been attempted in experimental models. Still, application to humans is questionable. In CE, although prospective clinical studies are still lacking, therapeutic, non-surgical drainage techniques, such as PAIR (puncture, aspiration, injection, re-aspiration) and its derivatives, are now considered a useful option in selected cases. Finally, palliative, non-surgical drainage techniques such as US- or CT-guided percutaneous biliary drainage, centro-parasitic abscesses drainage, or vascular stenting were performed successfully. Recently, endoscopic retrograde cholangiopancreatography (ERCP)-associated techniques have become increasingly used to manage biliary fistulas in CE and biliary obstructions in AE. Development of pre-clinical animal models would allow testing for AE techniques developed for other indications, e.g. cancer. Prospective trials are required to determine the best use of PAIR, and associated procedures, and the indications and techniques of palliative drainage.

IL-4 specific-response in whole blood associates with human Cystic Echinococcosis and cyst activity

OBJECTIVES

Human Cystic Echinococcosis (CE) is estimated in 2-3 million global cases. CE diagnosis and clinical management are based on imaging and serology, which lacks sensitivity and does not provide cyst stage information. This study aimed to evaluate tools for improving diagnosis by analysing the Interleukin (IL)-4-response to Antigen B (AgB) of Echinococcus granulosus.

METHODS

Whole blood (WB) and peripheral blood mononuclear cells were stimulated with AgB. IL-4 levels were measured by enzyme-linked immunosorbent assay.

RESULTS

WB 1-day stimulation resulted the best experimental condition for evaluating AgB IL-4-response. IL-4 levels were significantly higher in CE patients than healthy donors (p ≤ 0.0001). A ROC analysis showed significant area under the curve (AUC) results (AUC, 0.85; p = 0.0001) identifying an IL-4 level cut-off point ≥0.39 pg/mL which predicted CE with 71.4% sensitivity and 93.3% specificity. Moreover, we found that IL-4 levels were significantly increased in patients with active cysts compared to those with inactive cysts (p ≤ 0.0001). ROC analysis showed significant AUC results (0.94; p = 0.0001) with a cut-off point of 4.6 pg/mL which predicted active cysts with 84.6% sensitivity and 92% specificity.

CONCLUSIONS

We found immunological correlates associated with CE and biological cyst activity.

Medical treatment versus "Watch and Wait" in the clinical management of CE3b echinococcal cysts of the liver

Background

Available treatments for uncomplicated hepatic cystic echinococcosis (CE) include surgery, medical therapy with albendazole (ABZ), percutaneous interventions and the watch-and-wait (WW) approach. Current guidelines indicate that patients with hepatic CE should be assigned to each option based on cyst stage and size, and patient characteristics. However, treatment indications for transitional CE3b cysts are still uncertain. These cysts are the least responsive to non-surgical treatment and often present as indolent, asymptomatic lesions that may not warrant surgery unless complicated. Evidence supporting indications for treatment of this stage is lacking. In the attempt to fill this gap before the implementation of randomized clinical trials, we compared the clinical behavior of single hepatic CE3b cysts in 60 patients followed at the WHO Collaborating Centre for Cystic Echinococcosis of the University of Pavia.

Methods

We analyzed retrospectively data of 60 patients with hepatic CE3b cysts seen at our clinic over 27 years, who either received ABZ or were monitored with WW. Univariate and multivariate analysis were performed to investigate the effect on outcome (inactivation or relapse) of variables such as age, sex, origin, treatment, cyst size and presence of other echinococcal hepatic cysts using a multiple failure Cox proportional hazard model.

Results

ABZ treatment was positively associated with inactivation (p < 0.001), but this was not permanent, and no association was found between therapeutic approach and relapse (p = 0.091). No difference was found in the rate of complications between groups.

Conclusions

In conclusion, our study shows that ABZ treatment induces temporary inactivation of CE3b cysts, while during WW cysts remain stable over time. As the rate of adverse events during periods of ABZ treatment and WW did not differ significantly in the follow-up period considered in this study (median 43 months, IQR 10.7-141.5), expectant management might represent a valuable option for asymptomatic CE3b cysts when strict indication for surgery is absent and patients comply with regular long-term follow-up.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-492) contains supplementary material, which is available to authorized users.

Long-term sonographic and serological follow-up of inactive echinococcal cysts of the liver: hints for a "watch-and-wait" approach

Human cystic echinococcosis is a chronic, complex and neglected infection. Its clinical management has evolved over decades without adequate evaluation of efficacy. Recent expert opinion recommends that uncomplicated inactive cysts of the liver should be left untreated and solely monitored over time ("watch-and-wait" approach). However, clinical data supporting this approach are still scant and published mostly as conference proceedings. In this study, we report our experience with long-term sonographic and serological follow-up of inactive cysts of the liver. From March 1994 to October 2013, 38 patients with 47 liver cysts, diagnosed as inactive without any previous treatment history, were followed with ultrasound and serology at 6-12 months intervals for a period of at least 24 months (median follow-up 51.95 months) in our outpatient clinic. In 97.4% of patients, the cysts remained inactive over time and in only one case was reactivation of the cyst detected. No complications occurred during the time of monitoring. During follow-up, serology tests for CE were negative at diagnosis or became negative in 74.1% and were positive or became positive in 25.9% of cases. Patients with inactive cysts on ultrasound but positive serological tests were also investigated by CT scan (chest and abdomen) to rule out extra-hepatic cyst localization. This study confirms the importance of a stage-specific approach to the management of cystic echinococcosis and supports the use of a monitoring-only approach to inactive, uncomplicated cysts of the liver. It also confirms that serology plays only an ancillary role in the clinical management of these patients, compared to ultrasound and other imaging techniques. The implications of these findings for clinical management and natural history of cystic echinococcosis are discussed.

Cystic echinococcosis of the liver: A primer for hepatologists

Cystic echinococcosis (CE) is a complex, chronic and neglected disease with a worldwide distribution. The liver is the most frequent location of parasitic cysts. In humans, its clinical spectrum ranges from asymptomatic infection to severe, potentially fatal disease. Four approaches exist in the clinical management of CE: surgery, percutaneous techniques and drug treatment for active cysts, and the ”watch and wait” approach for inactive cysts. Allocation of patients to these treatments should be based on cyst stage, size and location, available clinical expertise, and comorbidities. However, clinical decision algorithms, efficacy, relapse rates, and costs have never been properly evaluated. This paper reviews recent advances in classification and diagnosis and the currently available evidence for clinical decision-making in cystic echinococcosis of the liver.

Recombinant AgB8/1 ELISA test vs. commercially available IgG ELISA test in the diagnosis of cystic echinococcosis

The diagnosis and clinical management of cystic echinococcosis (CE) rely on imaging and serology, the latter still having a complementary role as its accuracy in assessing cyst viability is unsatisfactory. We used an experimental IgG ELISA test based on the recombinant antigen rEgAgB8/1 cloned from Echinococcus granulosus to differentiate active from inactive/cured CE infection, comparing its performance to that of a commercially available ELISA test used routinely in our hospital laboratory. Both tests were performed on sera from 88 patients with hepatic echinococcal cysts, grouped according to cyst stage based on ultrasonographical morphology, and on 17 patients surgically treated for echinococcosis and 18 patients with nonparasitic hepatic cysts included as controls. Tests' performances did not differ significantly, but the overall concordance between tests drastically dropped when groups were analysed separately. Further longitudinal studies should evaluate whether these discrepancies reflect the different ability of either test to predict the evolution of cysts over time. Although the recombinant-AgB8/1-based ELISA test seems to have no clinical advantage over the commercially available ELISA test in the assessment of hepatic CE cyst viability, the easiness of production and reproducibility of high-quality recombinant antigens makes rEgAgB8/1 a valid candidate for use in CE ELISA diagnostic tests.

Immunoblotting with human native antigen shows stage-related sensitivity in the serodiagnosis of hepatic cystic echinococcosis

The diagnosis of hepatic cystic echinococcosis is based on ultrasonography and confirmed by serology. However, no biological marker of cyst viability is currently available implying years-long patient follow-up, which is not always feasible in endemic areas. We characterized the performance of an immunoblotting test based on human hydatid cyst fluid with particular regard to its ability to distinguish between cyst stages. Sera from patients with cysts in different stages showed distinctive band pattern recognition. Most importantly, the test discriminated in 80% of cases CE3a from CE3b transitional cysts, known to have different viability profiles. Interestingly, we observed a rapid change in band pattern recognition of sera from one patient at time points when his cyst passed from active to transitional to inactive stages. Further identification of different antigens expressed by different cyst stages will support the development of diagnostic tools that could early define cyst viability, to guide clinical decision making, and shorten patient follow-up.

Unusual growth rate during cystic echinococcosis

Cystic echinococcosis is a world wild zoonosis caused by Echinococcus granulosus, leading to hepatic and lung cysts with a usually slight growth rate. We report the case of an 82year-old Algerian woman with hepatic and lung cystic echinococcosis with a 10-fold size increase in 6months.

Unexpected discovery of massive liver echinococcosis. A clinical, morphological, and functional diagnosis

We report a case of symptomatic massive liver echinococcosis due to Echinococcus granulosus, unexpectedly found in a 34 year old woman living in Apulia, Italy. Based on size (max diameter 18 cm), clinical presentation, geographical area, and natural history of echinococcosis, we estimate that the initial infection should have occurred 9-20 yrs before. Presenting symptoms were those of typical mass effect with RUQ pain, pruritus, malaise, and recent weight loss. Abdominal ultrasound diagnosis of probable echinococcal cyst was subsequentely confirmed by positive serology and further detailed by radiological imaging. The cyst was massively occupying subdiaphragmatic liver segments and extending to the omentum and the stomach. The characteristics of the lesion were compatible with the WHO 2003 classification type CE2l, indicating a large active fertile cyst with daughter cysts. The cyst was successfully treated with medical therapy followed by surgery. The prevalence, diagnostic workup, management, and costs of echinococcosis are discussed in this case presentation.

Extrahepatic textiloma long misdiagnosed as calcified echinococcal cyst

Textiloma or gossypiboma is a retained surgical swab in the body after an operation and is a complication that can remain undetected for many years and may represent a diagnostic dilemma depending on its location. It may be confused with several focal lesions and an accurate history taking, combined with clinical and instrumental data, is key to suspecting the diagnosis. We report a case of abdominal textiloma that was initially misdiagnosed as echinococcal cyst and discuss the differential diagnosis based on sonographic features and the WHO-IWGE classification.

Cystic and alveolar echinococcosis

Echinococcosis of the CNS is very rare. Cystic (CE) and alveolar echininococcosis (AE) vary in their clinical manifestations, course of disease, and prognosis, to the extent that clinicians should look at these two parasitic infections as distinctly different entities. CE causes displacement and pressure atrophy, while AE expands by infiltrative growth. Due to the embolic nature of CE and AE, CNS lesions are most commonly localized supratentorially in the middle cerebral artery. Symptoms and clinical signs are those of space-occupying lesions. Diagnosis is primarily based on imaging (MRI, CT); serology can help to confirm the diagnosis, but is unreliable. In vivo MRS techniques for immobile intracranial CE lesions have become feasible and will assist in diagnosing such lesions in the future. Patients with cerebral CE and AE need an individual therapeutic approach and should generally be managed by a multidisciplinary team of clinicians experienced in the management of CE and neurosurgeons. A minimum follow-up of 5 years, but ideally 10 years, is necessary. Treatment is difficult in advanced disease, in particular in AE, when curative surgery is not possible. AE and CE are among the most neglected infectious diseases and urgently need more attention to improve early detection in exposed populations, diagnosis, and treatment.

Diagnosing and staging of cystic echinococcosis: how do CT and MRI perform in comparison to ultrasound?

BACKGROUND

Imaging plays the key role in diagnosing and staging of CE. The description of CE-specific imaging features and the WHO CE cyst classification is based on ultrasound. The reproducibility of the ultrasound-defined features of CE cysts is variable in MR- and CT-imaging. This is of particular importance for cysts that are not accessible by US and because of the increasing availability and overuse of CT and MR imaging.

METHODOLOGY/PRINCIPAL FINDINGS

Retrospective analysis of patients with abdominal CE cysts of an interdisciplinary CE clinic who had CT and/or MRI scans performed additionally to US imaging. All images were read and interpreted by the same senior radiologist experienced in the diagnosis of CE. US, CT and MR images were staged according to the WHO classification criteria. The agreement beyond chance was quantified by kappa coefficients (κ). 107 patients with 187 CE cysts met the inclusion criteria. All cysts were assessed by US, 138 by CT, and 125 by MRI. The level of agreement beyond chance of the individual CE stages 1-4 was clearly lower for CT, with κ ranging from 0.62 to 0.72, compared to MRI with values of κ between 0.83 and 1.0. For CE5 cysts CT (κ = 0.95) performed better than MRI (κ = 0.65).

CONCLUSIONS

Ultrasound remains the corner stone of diagnosis, staging and follow up of CE cysts. MRI reproduces the ultrasound-defined features of CE better than CT. If US cannot be performed due to cyst location or patient-specific reasons MRI with heavily T2-weighted series is preferable to CT.

Cestode infestations: hydatid disease and cysticercosis

Although humans can be definitive hosts for cestodes (tapeworms), major pathologic conditions occur during cestode larval stages when humans serve as the intermediate host for these parasites. The most relevant forms of human disease caused by cestode larvae are echinococcosis, caused by Echinococcus granulosus (cystic echinococcosis) and Echinococcus multilocularis (alveolar echinococcosis), and cysticercosis, caused by Taenia solium. These infections occur worldwide, but their relevance is particularly high in developing countries, where poor hygiene conditions facilitate the transmission of the parasites. The therapeutic approach is often complex, requiring surgery and/or chemotherapy or, in the case of cystic echinococcosis, percutaneous treatments.

Improved serodiagnosis of cystic echinococcosis using the new recombinant 2B2t antigen

A standardized test for the serodiagnosis of human cystic echinococcosis (CE) is still needed, because of the low specificity and sensitivity of the currently available commercial tools and the lack of proper evaluation of the existing recombinant antigens. In a previous work, we defined the new ELISA-B2t diagnostic tool for the detection of specific IgGs in CE patients, which showed high sensitivity and specificity, and was useful in monitoring the clinical evolution of surgically treated CE patients. Nevertheless, this recombinant antigen gave rise to false-negative results in a percentage of CE patients. Therefore, in an attempt to improve its sensitivity, we constructed B2t-derived recombinant antigens with two, four and eight tandem repeat of B2t units, and tested them by ELISA on serum samples of CE patients and patients with related parasites. The best diagnostic values were obtained with the two tandem repeat 2B2t antigen. The influence of several clinical variables on the performance of the tests was also evaluated. Finally, the diagnostic performance of the 2B2t-ELISA was compared with that of an indirect haemagglutination commercial test. The 2B2t recombinant antigen performed better than the HF and B2t antigens, and the IHA commercial kit. Therefore, this new 2B2t-ELISA is a promising candidate test for the serodiagnosis of CE in clinical settings.

Cystic echinococcosis (CE) is a widespread zoonotic disease. Its complex clinical presentation precludes a “one-size-fits-all” approach to clinical management, particularly with regard to serodiagnosis. While CE is often detected incidentally by imaging, imaging findings may be inconclusive. Therefore, there is a need for standardised and approachable diagnostic tools that may complement imaging data. In this regard, serological tests based in the use of native antigens like hydatid fluid present a low specificity and sensitivity. Although recombinant antigens with potential to replace native antigens have been proposed in the literature, none has been systematically tested for diagnostic performance. Here, we describe the new recombinant antigen 2B2t, derived from the previously described recombinant B2t, and determine its usefulness for the serodiagnosis of CE by ELISA in patients with a complete set of clinical data. The influence of clinical variables on the performance of 2B2t was evaluated and compared with the hydatid fluid (the most commonly used antigen for CE serology) and a commercial diagnostic kit based on the haemagglutination reaction. Our results show that the 2B2t antigen has potential to be routinely used for the standardised diagnosis of CE in clinical settings.

Hepatic echinococcosis: clinical and therapeutic aspects

Echinococcosis or hydatid disease (HD) is a zoonosis caused by the larval stages of taeniid cestodes belonging to the genus Echinococcus. Hepatic echinococcosis is a life-threatening disease, mainly differentiated into alveolar and cystic forms, associated with Echinoccus multilocularis (E. multilocularis) and Echinococcus granulosus (E. granulosus) infection, respectively. Cystic echinococcosis (CE) has a worldwide distribution, while hepatic alveolar echinococcosis (AE) is endemic in the Northern hemisphere, including North America and several Asian and European countries, like France, Germany and Austria. E. granulosus young cysts are spherical, unilocular vesicles, consisting of an internal germinal layer and an outer acellular layer. Cyst expansion is associated with a host immune reaction and the subsequent development of a fibrous layer, called the pericyst; old cysts typically present internal septations and daughter cysts. E. multilocularis has a tumor-like, infiltrative behavior, which is responsible for tissue destruction and finally for liver failure. The liver is the main site of HD involvement, for both alveolar and cystic hydatidosis. HD is usually asymptomatic for a long period of time, because cyst growth is commonly slow; the most frequent symptoms are fatigue and abdominal pain. Patients may also present jaundice, hepatomegaly or anaphylaxis, due to cyst leakage or rupture. HD diagnosis is usually accomplished with the combined use of ultrasonography and immunodiagnosis; furthermore, the improvement of surgical techniques, the introduction of minimally invasive treatments [such as puncture, aspiration, injection, re-aspiration (PAIR)] and more effective drugs (such as benzoimidazoles) have deeply changed life expectancy and quality of life of patients with HD. The aim of this article is to provide an up-to-date review of biological, diagnostic, clinical and therapeutic aspects of hepatic echinococcosis.

Serum cytokine profile by ELISA in patients with echinococcal cysts of the liver: a stage-specific approach to assess their biological activity

To investigate the usefulness of serum cytokine dosage in the clinical management of cystic echinococcosis (CE), we analyzed serum levels of Th1 and Th2 cytokines in patients with hepatic CE in different cyst stages, CE1-2 (active), CE3a-3b (transitional), and CE4-5 (inactive). Ex vivo assessment of Th1 (IFN-γ) and Th2 (IL-4, IL-13, and IL-10) cytokines in sera was carried out using ELISA. IL-10 was undetectable in all serum samples of patients and controls, while a few sera contained measurable amounts of IFN-γ, IL-4, and IL-13. No statistically significant difference was found between the percentages of positive samples for each cytokine and the different groups analyzed (patients/controls, stage, number, location, and size of the cyst, serology, and sex of patients), with the exception of the association of IL-4 and IL-13 with the cyst stage. Overall, this investigation showed many limits of serum cytokine dosage as a marker of biological activity of echinococcal cysts. Because of low sensitivity and lack of specificity of this test, we believe that other ways to evaluate ex vivo biological activity of the cysts should be explored.

Early diagnosis, treatment and follow-up of cystic echinococcosis in remote rural areas in Patagonia: impact of ultrasound training of non-specialists

Cystic echinococcosis (CE) is a chronic, complex and neglected disease caused by the larval stage of Echinococcus granulosus. The effects of this neglect have a stronger impact in remote rural areas whose inhabitants have no chances of being diagnosed and treated properly without leaving their jobs and travelling long distances, sometimes taking days to reach the closest referral center.

BACKGROUND

In 1980 our group set up a control program in endemic regions with CE in rural sections of Rio Negro, Argentina. Since 1997, we have used abdominopelvic ultrasound (US) as a screening method of CE in school children and determined an algorithm of treatment.

OBJECTIVES

To describe the training system of general practitioners in early diagnosis and treatment of CE and to evaluate the impact of the implementation of the field program.

MATERIALS AND METHODS

In 2000, to overcome the shortage of radiologists in the area, we set up a short training course on Focused Assessment with Sonography for Echinococcosis (FASE) for general practitioners with no previous experience with US. After the course, the trainees were able to carry out autonomous ultrasound surveys under the supervision of the course faculty. From 2000 to 2008, trainees carried out 22,793 ultrasound scans in children from 6 to 14 years of age, and diagnosed 87 (0.4%) new cases of CE. Forty-nine (56.4%) were treated with albendazole, 29 (33.3%) were monitored expectantly and 9 (10.3%) were treated with surgery.

DISCUSSION

The introduction of a FASE course for general practitioners allowed for the screening of CE in a large population of individuals in remote endemic areas with persistent levels of transmission, thus overcoming the barrier of the great distance from tertiary care facilities. The ability of local practitioners to screen for CE using US saved the local residents costly travel time and missed work and proved to be an efficacious and least expensive intervention tool for both the community and health care system.

Efficacy and safety of PAIR for cystic echinococcosis: experience on a large series of patients from Bulgaria

We report our experience with puncture, aspiration, injection, and reaspiration (PAIR) for the treatment of cystic echinococcosis in Bulgaria. PAIR was performed in 230 patients with 348 echinococcal cysts. At 12-month follow-up, 77.6% of the cysts, all cystic echinococcosis (CE) 1 and CE3a cysts according to the World Health Organization Informal Working Group classification, showed various degrees of obliteration. In 11.5% of cysts, all of which were > 10 cm-type CE1, a significant amount of fluid persisted, and they were punctured again. Of those, 16 (4.6%) contained protoscolices and were treated by a second PAIR. The remaining 24 (6.9%) cysts were treated by simple aspiration or drainage. No significant reduction in size and no changes in the structure were observed in 10.9% of cysts, all of which were classified as CE2 or CE3b. Complications developed in 25.2% of patients, including severe anaphylactic reaction in two (0.9%) patients. Our experience confirms that PAIR is a successful first-choice treatment when a stage-specific approach is taken.

Expert consensus for the diagnosis and treatment of cystic and alveolar echinococcosis in humans

The earlier recommendations of the WHO-Informal Working Group on Echinococcosis (WHO-IWGE) for the treatment of human echinococcosis have had considerable impact in different settings worldwide, but the last major revision was published more than 10 years ago. Advances in classification and treatment of echinococcosis prompted experts from different continents to review the current literature, discuss recent achievements and provide a consensus on diagnosis, treatment and follow-up. Among the recognized species, two are of medical importance -Echinococcus granulosus and Echinococcus multilocularis - causing cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. For CE, consensus has been obtained on an image-based, stage-specific approach, which is helpful for choosing one of the following options: (1) percutaneous treatment, (2) surgery, (3) anti-infective drug treatment or (4) watch and wait. Clinical decision-making depends also on setting-specific aspects. The usage of an imaging-based classification system is highly recommended. For AE, early diagnosis and radical (tumour-like) surgery followed by anti-infective prophylaxis with albendazole remains one of the key elements. However, most patients with AE are diagnosed at a later stage, when radical surgery (distance of larval to liver tissue of >2cm) cannot be achieved. The backbone of AE treatment remains the continuous medical treatment with albendazole, and if necessary, individualized interventional measures. With this approach, the prognosis can be improved for the majority of patients with AE. The consensus of experts under the aegis of the WHO-IWGE will help promote studies that provide missing evidence to be included in the next update.

Update on cystic hydatid disease

PURPOSE OF REVIEW

Cystic echinococcosis, or cystic hydatidosis, is a complex, chronic disease with a cosmopolitan distribution. In humans, its clinical spectrum ranges from asymptomatic infection to severe, rarely even fatal disease. Four approaches in clinical management exist: surgery, percutaneous techniques and drug treatment for active cysts, and the so-called watch and wait approach for inactive cysts. Allocation of patients to these treatments should be based on cyst stage, size and location, available clinical expertise and comorbidities. However, clinical decision algorithms, efficacy, relapse rates, and costs have never been properly evaluated.We review the currently available evidence for clinical decision-making and discuss ways to improve standards of care of one of the most neglected infectious diseases.

RECENT FINDINGS

Data are mostly derived from case series and small clinical trials, and treatment guidelines remain at the level of expert opinion. No single high-quality comparative clinical trial of the four treatment options is available to resolve important questions such as stage-specific allocation of treatments, adverse events and long-term relapse rates. Recent work is beginning to acknowledge this problem.

SUMMARY

Currently, four treatment modalities are available for cystic echinococcosis. The level of evidence on which clinicians have to rely is low. For the time being patients should thus be treated in referral centres. Proper comparative clinical trials are urgently needed.

Echinococcus metacestodes as laboratory models for the screening of drugs against cestodes and trematodes

Among the cestodes, Echinococcus granulosus, Echinococcus multilocularis and Taenia solium represent the most dangerous parasites. Their larval stages cause the diseases cystic echinococcosis (CE), alveolar echinococcosis (AE) and cysticercosis, respectively, which exhibit considerable medical and veterinary health concerns with a profound economic impact. Others caused by other cestodes, such as species of the genera Mesocestoides and Hymenolepis, are relatively rare in humans. In this review, we will focus on E. granulosus and E. multilocularis metacestode laboratory models and will review the use of these models in the search for novel drugs that could be employed for chemotherapeutic treatment of echinococcosis. Clearly, improved therapeutic drugs are needed for the treatment of AE and CE, and this can only be achieved through the development of medium-to-high throughput screening approaches. The most recent achievements in the in vitro culture and genetic manipulation of E. multilocularis cells and metacestodes, and the accessability of the E. multilocularis genome and EST sequence information, have rendered the E. multilocularis model uniquely suited for studies on drug-efficacy and drug target identification. This could lead to the development of novel compounds for the use in chemotherapy against echinococcosis, and possibly against diseases caused by other cestodes, and potentially also trematodes.

Metabolomics: moving to the clinic

Assessment of a biological system by means of global and non-targeted metabolite profiling--metabolomics or metabonomics--provides the investigator with molecular information that is close to the phenotype in question in the sense that metabolites are an ultimate product of gene, mRNA, and protein activity. Over the last few years, there has been a rapidly growing number of metabolomics applications aimed at finding biomarkers which could assist diagnosis, provide therapy guidance, and evaluate response to therapy for particular diseases. Also, within the fields of drug discovery, drug toxicology, and personalized pharmacology, metabolomics is emerging as a powerful tool. This review seeks to update the reader on analytical strategies, biomarker findings, and implications of metabolomics for the clinic. Particular attention is paid to recent biomarkers found related to neurological, cardiovascular, and cancer diseases. Moreover, the impact of metabolomics in the drug discovery and development process is examined.