Immunobiology of cystic echinococcosis

The present report focuses on the ability of cystic echinoccocosis metacestode to survive for a long time, despite host immunity, by developing avoidance strategies. The tactics believed to come into play, ranging from intrinsic parasitic factors to host-related mechanisms, are briefly discussed and the importance of studies on experimental models is highlighted particularly in relation to furthering the theoretical understanding of the dynamic equilibrium between host and parasite, and to the feasibility of practical approaches in controlling the disease by artificial manipulation of the immunoregulatory mechanisms.     

Past and present of cystic echinococcosis in Bolivia

Viable eggs of the canine intestinal tapeworm Echinococcus granulosus sensu lato (s.l.) infect various intermediate hosts causing cystic echinococcosis (CE). Furthermore, CE represents a serious zoonosis causing a significant global burden of disease. CE is highly endemic in South America, including Argentina, Brazil, Chile, Uruguay, and Peru. For Bolivia, no official data concerning the incidence in humans or the number of livestock and dogs infected are available. However, it is well known that CE occurs in Bolivia. We aim here to fill the gap in the current knowledge of the epidemiological situation of CE in Bolivia, providing a historical overview of documents published within the country, which have never been comprehensively reviewed. The very first documentation of E. granulosus infection in animals dates in 1910, while the first human case was reported in 1913. In total, 876 human CE cases have been reported in the scientific literature, with an apparent increase since the 1970s. In the absence of other epidemiological studies, the highest prevalence in human comes from Tupiza, Potosí Department, where 4.1% (51/1,268) of the population showed signs of CE at mass ultrasound screening in 2011. In the same report, 24% of dog faecal samples were positive for coproantigens of E. granulosus s.l. in ELISA. The highest prevalence in intermediate hosts reported at abattoir reached 37.5% in cattle from Potosí, followed by 26.9% in llamas from Oruro, 2.4% in pigs and 1.4% in sheep from La Paz. Finally, Echinococcus granulosus sensu stricto (s.s.), Echinococcus ortleppi (G5), and Echinococcus intermedius (G7) have been identified in Bolivia. Data reviewed here confirm that E. granulosus s.l. is circulating in Bolivia and that a proper prospective nationwide epidemiological study of CE is urgently needed to define transmission patterns as a basis for the planning and implementation of future control measurements.     

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 82 year-old Algerian woman with hepatic and lung cystic echinococcosis with a 10-fold size increase in 6 months.     

Overview of therapeutic options for cystic echinococcosis

Surgical excision of echinococcal cyst has long been considered the only effective treatment for echinococcosis. However, the remarkable advances in imaging techniques, particularly ultrasound, made during the past 25 years have greatly facilitated diagnosis, treatment and follow-up. Today, chemotherapy and percutaneous treatments have become widely available. A major step forward in management of the disease came in 2001, when the WHO International Working Group on Echinococcosis (WHO-IWGE) came to a consensus by developing a standardized classification of ultrasound images in cystic echinococcosis. Thus, the most appropriate treatment for patients affected by this serious and sometimes life-threatening disease may now be chosen. An overview of the three main therapeutic options for abdominal- and particularly hepatic-cystic echinococcosis is presented, with focus on the indications and contraindications of each one. Data from long-term follow-up studies are also discussed, with emphasis on the resulting stage-specific criteria for treatment.     

Recombinant antigens for immunodiagnosis of cystic echinococcosis

Three cDNAs, termed EpC1, TPxEg and EgG5, were isolated by immunoscreening from an Echinococcus granulosus cDNA library. The recombinant phages exhibited strong reactivity with sera from humans with confirmed cystic echinococcosis (CE) and with sera from mice infected with E. granulosus oncospheres. The cDNAs were subcloned into a pET vector, expressed as fusion proteins tagged with GST and affinity purified against the GST tag. Of the three recombinant proteins, EpC1 achieved the highest performance for serodiagnosis of CE in Western blot analysis using a panel of clinically defined human sera to initially address the sensitivity and specificity of the molecules. The protein yielded an overall sensitivity of 92.2% and specificity of 95.6%, levels unprecedented taking into account the large panel of 896 human sera that were tested. The strategy used may also prove suitable for improved immunodiagnosis of other parasitic infections.     

Economic impact of cystic echinococcosis in peru

Background

Cystic echinococcosis (CE) constitutes an important public health problem in Peru. However, no studies have attempted to estimate the monetary and non-monetary impact of CE in Peruvian society.

Methods

We used official and published sources of epidemiological and economic information to estimate direct and indirect costs associated with livestock production losses and human disease in addition to surgical CE-associated disability adjusted life years (DALYs) lost.

Findings

The total estimated cost of human CE in Peru was U.S.$2,420,348 (95% CI:1,118,384–4,812,722) per year. Total estimated livestock-associated costs due to CE ranged from U.S.$196,681 (95% CI:141,641–251,629) if only direct losses (i.e., cattle and sheep liver destruction) were taken into consideration to U.S.$3,846,754 (95% CI:2,676,181–4,911,383) if additional production losses (liver condemnation, decreased carcass weight, wool losses, decreased milk production) were accounted for. An estimated 1,139 (95% CI: 861–1,489) DALYs were also lost due to surgical cases of CE.

Conclusions

This preliminary and conservative assessment of the socio-economic impact of CE on Peru, which is based largely on official sources of information, very likely underestimates the true extent of the problem. Nevertheless, these estimates illustrate the negative economic impact of CE in Peru.     

Natural history of cystic echinococcosis in humans

This study provides a contribution to understanding of the natural history of the hydatid cyst during its evolution in the human liver examining the high morphostructural variability of larval forms of Echinococcus granulosus. A detailed study of a large sample of intact cysts removed from patients surgically treated by means of total pericystectomy, has enabled to outline the different developmental stages of the parasite over time, up to its death and complete degeneration.     

Notes on cystic echinococcosis in the Mediterranean

Cystic Echinococcosis (CE), caused by Echinococcus granulosus, is present from the beginning of history and in the Mediterranean it is linked to the dog-sheep cycle. The Mediterranean area possesses many features favouring CE. Positive and negative influences derived from the action of the European Community and from recent developments. The control measures of CE have political, economic, public health and environmental implications. Dog population and dog-transmitted zoonoses control, improvement of slaughtering procedures and the destruction of infected viscera, health education, interprofessional cooperation are able individually to constitute a contraposition to CE and combined to compose a control program. Epidemiological surveillance and control of CE in the Mediterranean are coordinated by the WHO Mediterranean Zoonoses Control Centre of Athens.     

Molecular confirmation of a case of multiorgan cystic echinococcosis

We report on the results of radical surgery performed on a 10-yr-old Chinese female with multiple echinococcosis lesions and the diagnosis of the infection by imaging, histology, serology, and DNA analysis. Molecular genotyping provided unequivocal proof that the patient was infected with Echinococcus granulosus, the cause of cystic echinococcosis.     

Notes on human cases of cystic echinococcosis in Peru

Cystic echinococcosis (CE) is a high prevalent zoonosis in the central and southern Peruvian Andes. Serum samples (n50)from patients presenting presumptive clinical and radiological diagnosis of CE (group 1), were tested for antibodies against Echinococcus granulosus metacestode using Arc-5 double diffusion assay (DD5), immunoelectrophoresis (IEF), and immunoelectrotransfer blot (EITB) techniques. Serum samples (n18) from patients presenting other parasite infections (paragonomiasis, cysticercosis, and fascioliasis) or healthy blood donors (n15), were designated as control groups. The overall sensitivity of the tests was of 94% (DD5 and IEF tests) or 96% (EITB test). Only patients from group 1 were seropositive for CE. Polypeptides of 21, 31, and 48 kDa were considered positive for CE. Based on these results, this study demonstrates that CE also occurs in other coastal departments (Piura, Ancash, Ica, Arequipa, and Tacna) besides Lima.     

An up-to-date on clinical management of human cystic echinococcosis

More than one thousand of patients with more than two thousand of Echinococcus granulosus hydatid cysts were observed during the last 20 years. The therapeutic approach ranged from chemotherapy with benzimidazole carbamates (mebendazole and albendazole) to surgery, percutaneous non conventional treatment, and a "wait and see" approach, on the basis of the clinical picture, of the compliance and of the socio-economic background of each patient. The observed results, mainly those regarding chemotherapy, were briefly summarized and discussed. Most important point to underline is the need of data about a more prolonged follow-up on wider casuistries of patients both treated (with chemotherapy, with surgery, with percutaneous non conventional treatment) and not treated, to obtain a more suitable evaluation of the long-term outcome of the performed clinical approach. Moreover, a multidisciplinary approach is advisable to assure a better clinical management to patients with cystic echinococcosis.     

A case of human cystic echinococcosis acquired in Ireland

Cystic echinococcosis (CE) is caused by the cestodes of the Echinococcus granulosus sensu lato complex and, in the majority of cases, is associated with hepatic or pulmonary involvement. Human CE is not thought to be endemic in Ireland. We describe the first reported case of human CE possibly acquired in Ireland.     

Updates on cystic echinococcosis (CE) in Italy

An update on Cystic Echinococcosis (CE) diffusion in Italy during 2003-2005 is reported. CE seems to have a sporadic diffusion in the northern part of the country where this disease plays a minor role (prevalence < 1%). Recent investigations have shown the occurrence of CE cases in humans from the mountains between Reggio Emilia and Modena, with an average year incidence between 9.4 and 5.6/100,000. In Abruzzo prevalences in sheep and cattle are 20.2% and 15.3%, with a fertility of 4.6% and 1.3%, respectively. In the same region, G1 and G3 strains were identified and a prevalence of 31% in dogs was found with CaELISA. In Campania, CE prevalence was 14.8% in cattle, with no viable cysts recovered, and 10.5% in water buffaloes, with a fertility of 1.4%. Biotechnologies allowed to find G1 and G3 strains in water buffaloes. In Sicily, CE was found in 67.1% of cattle, with a fertility of 4%, and in 57.6% of sheep, with 9.2% of viable cysts. Biomolecular investigations have found G1 strain in sheep and cattle. In dogs, a prevalence of 5.6% for Echinococcus granulosus was reported. In Sardinia CE prevalence was 75.3% in sheep and 41.5% in cattle, with a fertility of 10.3% and 2.6%, respectively. CE was found also in 9.4% of pigs, with fertility of 6.5%. The G1 strain was recovered in sheep and cattle while the G7 in pigs.     

Comparative evaluation of western blotting in hepatic and pulmonary cystic echinococcosis

Many serological tests are widely used in the diagnosis of cystic echinococcosis (CE), caused by the larval stages of Echinococcus granulosus. The present study was carried for differentiation between hepatic and pulmonary cystic echinococcosis by Western Blotting (WB). A total of 121 sera from patients with hepatic CE (37), pulmonary CE (31) and controls (53; consisting of six healthy, seven Hymenolepis nana infection, 20 hepatic and 20 pulmonary diseases other than CE) were examined. In all of the CE patients, E. gronulosus infection was confirmed by surgical intervention. Sera were previously tested using IHA and ELISA to detect the E. gronulosus specific antibodies. Sera from hepatic cases of CE reacted with 16 polypeptides of 6-116 kDa and sera from pulmonary cases of CE reacted with 14 polypeptides of 4-130 kDa by Western Blotting. The WB test enabled the detection of antibodies in the hepatic CE samples for proteins of 24, 32 34, 44-46 and 52-54 kDa in molecular weight in 78.4%, 75.7%, 78.4% and 89.2% of the patients, respectively. In the pulmonary CE samples sera WB test enabled the detection of antibodies 24, 44-46, 100, 110, 116 and 120 124 kDa in molecular weight in 81.3%, 75.0%, 87.5%, 71.9%, 84.4% and 65.6% of the patients, respectively. We indicated that the antigenic components of high molecular weight can be good candidates for differentiation of hepatic CE from pulmonary CE.     

Critical points in the immunodiagnosis of cystic echinococcosis in humans

This study discusses the immunodiagnosis of cystic echinococcosis (ce, caused by Echinococcus granulosus). The detection by immunoblotting of antibodies specific for the 8 kDa subunit of antigen B and in particular the IgG4 subclass expression, seems the most promising serodiagnostic tool. Despite the development of molecular methods, nowadays there is no standard, highly sensitive, and specific test available for antibody detection in CE. Furthermore, because serological tests can give only a limited support to clinical findings there is a clear need for new advances in immunodiagnosis of E. granulosus infection.     

Molecular diagnosis of cystic echinococcosis in humans from central Poland

The identity of the causative agent of cystic echinococcosis (CE) in humans from central Poland receiving treatment between 2000 and 2010 was determined. A total of 47 samples obtained after hepatectomy were examined and protoscoleces were identified in wet preparations in 27 cases. Using DNA extracted from the samples, two mitochondrial regions (nad1 and cox1 genes) were amplified and the nad1 fragment was sequenced. This PCR analysis confirmed the presence of Echinococcus species in 30 cases and nad1 sequence alignments showed identity with the G7 (pig) strain, Echinococcus canadensis. These data demonstrate that the pig strain of this parasite is the most frequent causative agent of human cystic echinococcosis in central Poland.     

TAP1 and TAP2 gene polymorphisms in childhood cystic echinococcosis

The incidence of cystic echinococcosis (CE) due to Echinococcus granulosus is as high as 2000–2500 patients per year in Turkey. Whether genetic characteristics of the Turkish population cause a tendency to the disease is currently unknown. We aimed at studying the role of TAP gene polymorphisms in Turkish children with cystic echinococcosis. For an overview of allelic distribution of TAP1 and TAP2 genes, genotypes of 85 patients with CE and 100 controls were studied. To determine the genotype–phenotype correlation, 81 of the patients whose clinical data were available were analyzed. For TAP1-637, Asp/Gly heterozygosity was significantly more prevalent in CE patients than in controls (20 vs. 4%, odds ratio 6.0), while Gly/Gly homozygosity was less frequent (5 vs. 14%). For TAP2-379, Ile/Val heterozygosity was significantly more prevalent in CE patients than in controls (14 vs. 1%, odds ratio 16.27), while Ile/Ile homozygosity was less frequent (13 vs. 25%). TAP1-637 and TAP2-379 polymorphisms may have a role in causing genetic tendency for CE in children. The data may reflect the genetic properties of the Turkish population or may reveal the minor role of TAP gene polymorphisms in CE.     

Flubendazole in cystic echinococcosis therapy: Pharmaco-parasitological evaluation in mice

Cystic echinococcosis (CE) caused by the parasite Echinococcus granulosus is an important public health problem worldwide. Flubendazole has shown poor in vivo efficacy against CE in humans and mice. However, flubendazole causes marked in vitro damage on E. granulosus protoscoleces. The goals of the current work were: a) to compare the plasma pharmacokinetic behaviour of flubendazole formulated as a hydroxipropyl-β-cyclodextrin aqueous solution or as a carboxymethyl celullose suspension, both given by the oral route to mice, b) to compare flubendazole clinical efficacy in secondary CE in mice after its administration as both formulations, c) to evaluate the flubendazole-induced morphological changes in hydatid cysts recovered from infected mice treated with both drug formulations. Flubendazole administration as a solution resulted in significantly higher plasma maximum concentration (C_max) and area under the concentration–time curve (AUC) values compared to those obtained after the flubendazole-suspension treatment. This enhanced drug availability correlated with an increased efficacy against secondary CE in mice observed for the flubendazole-solution formulation, while the suspension formulation did not reach differences with the untreated control group. Similar ultrastructural changes were observed in cysts recovered from flubendazole (both formulations) treated mice after 3, 6 and 9 months of infection, although the damage extension was greater after treatment with the flubendazole-solution formulation.