Echinococcosis: historical landmarks and progress in research and control

Evaluation of structural changes of Echinococcus granulosus protoscoleces following exposure to different protoscolicidal solutions evaluated by differential interference contrast microscopy

The present study was aimed to assess the structural changes in protoscoleces of Echinococcus granulosus sensu stricto following exposure to different natural and chemical protoscolicidal agents using differential interference contrast (DIC)/Nomarski microscopy. Protoscoleces of sheep's liver cysts were collected aseptically. Individually, about 1000 protoscoleces were exposed to 0.5% silver nitrate, 20% hypertonic saline solution, 0.5% cetrimide solution and two different concentrations of garlic chloroformic extraction as well as phosphate-buffered saline (PBS). The protoscoleces viability was assessed using 0.1% eosin solution, and structural modifications in the protoscoleces were examined by DIC/Nomarski microscopy. The results revealed the degeneration of the tegument, disorganization of the hooks, and reduction of the size of the protoscoleces exposed to cetrimide, hypertonic sodium chloride, and silver nitrate. Furthermore, calcareous corpuscles became blurred and opaque and their numbers decreased in all the exposed samples except, those in PBS. The exposed protoscoleces to cetrimide and hypertonic sodium chloride solution showed extensive degeneration of the tegument and disorganization of the hooks. In the group exposed to 200 mg/ml chloroformic garlic extract, the protoscoleces' width decreased. The length, width, and number of calcareous corpuscles also decreased significantly in the silver nitrate-exposed protoscoleces. The study concludes that protoscoleces exposed to different solutions; cetrimide 0.5% and hypertonic sodium chloride 20% caused more pronounced structural changes in the exposed protoscoleces. These changes were well demonstrated by DIC microscopy and can be used as a supplementary tool to evaluate the effects of protoscolicidal agents.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-023-01632-4.

Primary pleural hydatidosis presenting as an isolated cough: A rare case report

INTRODUCTION AND IMPORTANCE

Echinococcus granulosus causes hydatid disease. The most affected organ is the liver which is followed by the lungs. The pleural cavity being the primary location of hydatid cysts is rare and should be discussed further. This paper documents a rare case of primary pleural hydatidosis which can present with a merely isolated cough followed by dyspnea. The diagnosis and surgical treatment along with post-operative medications are vital in this case.

CASE PRESENTATION

We present a case of a 45-year-old who suffered from a cough for more than one week which did not subside after taking medications. This symptom was followed by dyspnoea for which an X-ray was done which showed left-sided pleural effusion, a complication of pleural hydatidosis. Computed tomography showed multiple cysts in the pleural cavity which confirmed the diagnosis of primary pleural hydatidosis as the cysts were not present in any other sites. Blood work revealed eosinophilia which is significant in parasitic diseases. A left posterolateral thoracotomy was performed, and the cysts were surgically removed. Additionally, empyemectomy and pleurectomy were done. The patient was then treated with anti-parasitic therapy and was advised to get X-rays during the follow-up visits. The X-rays were normal and indicated that there was no disease recurrence.

CLINICAL DISCUSSION

Echinococcus granulosus is a parasitic worm that causes hydatid disease. The primary location is the liver. A diagnosis of intrathoracic but extrapulmonary disease, which involves the presence of hydatid cysts in the pleura, heart, pericardium, mediastinum, chest wall, and diaphragm, is difficult in individuals lacking a primary cyst in a common location (Isitmangil et al., 2003; Saeedan et al., 2020).

CONCLUSION

This case implies the significance of a cough of more than a week that is not relieved by medications. This should be carefully evaluated and followed in cases that have a rare diagnosis requiring surgery. A diagnosis of primary pleural hydatidosis with left-sided pleural effusion and atelectasis with mediastinal shift to the right side was made which was treated with a surgical procedure.

Effectiveness Evaluation of Viti's vinifera Leaf Extract on the Viability of Echinococcus Eggs and Protoscolices In Vitro

Echinococcosis is a zoonotic disease caused by the genus Echinococcus. Globally, it is one of the most central helminthic diseases. Surgery remains the method of choice to remove cystic Echinococcus. Various sporicidal agents have been used to invalidate the substances in hydatid cysts. Nevertheless, many sporicidal agents cause inflammation and can cause side complications, so their use should be limited. The study aims to evaluate the effectiveness of Vitis vinifera leaf methanolic extract as a sporicidal agent for Echinococcus eggs and protoscolices and determines the best concentration. The mortality and viability of protoscolices were measured in samples exposed to four concentrations of V. vinifera leaf extract (VVLE) (5, 10, 30, and 50 mg/mL) for 5, 10, 20, and 30 min and in eggs exposed to three concentrations (100, 200, and 300 mg/mL) for 24 and 48 h. An infrared spectroscopy chemical test was conducted to assess the presence of numerous expected active components in the extract. The viability of eggs and protoscolices was confirmed using 0.1% eosin staining. Vinifera leaf extract exhibited the decisive sporicidal effect at 100%, 91%, 60%, and 41% after 30 min at concentrations of 50, 30, 10, and 5 mg/mL, and in eggs at 11% and 19% after 24 and 48 h at a concentration of 200 mg/mL, respectively. Increased incubation times and higher dosages often increase mortality. The results exhibited that V. vinifera is effective. This study confirmed that grape leaf extract has high sporicidal activity in vitro. However, more studies are required to determine the exact active chemical and its action mechanism and perform in vivo utilization to confirm these results.

Seropositivity Pattern of Human Cystic Echinococcosis at a Tertiary Care Hospital of India

Cystic echinococcosis (CE), even after several control measures, causes significant morbidity throughout the world. Besides imaging investigation technology, the serological tests are essential for both diagnosis and management of this slowly progressive disease. The present study was a hospital-based retrospective study that examined the seropositivity rate for Echinococcus granulosus sensu lato antibody in patients suspected of CE at our tertiary health care center over 8 years from 2013 to 2020. Records of new visits to hospital/clinics and associated hospital discharge constituted the denominator of calculation. All samples were tested using commercially available indirect immunoglobulin G enzyme-linked immunosorbent assay kit. A total of 925 suspected patients with a clinical diagnosis of CE were screened. The age group that commonly tested positive for CE was 20 to 39 years, and liver was the predominant organ found to be affected. The seropositive rate was 41.2%. On further year-wise analysis, it was observed that the seropositivity rate had significantly declined from 61.4% in 2013 to 33.8% in 2020. This study clearly showed that there is a by 27.6% decline of CE seropositivity rate in 8 years. This declining rate may be attributed to improved socioeconomic status and better implementation of health programs.

Analysis of gene expression profile of peripheral blood in alveolar and cystic echinococcosis

RNA-sequencing (RNA-seq) is a versatile, high-throughput technology that is being widely employed for screening differentially expressed genes (DEGs) in various diseases. Echinococcosis, a globally distributed zoonosis, has been reported to impose a heavy disease burden in pastoral areas of China. Herein we aimed to explore the molecular mechanisms underlying echinococcosis. In this study, peripheral blood samples were collected from six patients with alveolar echinococcosis (AE), six patients with cystic echinococcosis (CE), and six healthy controls. RNA-Seq (mRNA) was performed to detect gene transcript and expression levels, and DEGs were subjected to bioinformatic analyses. In comparison with healthy controls, 492 DEGs (270 upregulated, 222 downregulated) were found in the AE group and 424 DEGs (170 upregulated, 254 downregulated) were found in the CE group (|log₂ (fold change)| > 1 and P < 0.05). Further, 60 genes were upregulated and 39 were downregulated in both the AE and CE groups. Gene ontology enrichment analysis indicated that DEGs were mainly involved in molecular functions, including extracellular space, extracellular region, organ and system development, and anatomical structure development. Protein–protein interaction (PPI) networks were constructed to depict the complex relationship between DEGs and interacting proteins.

Feasibility and acceptability of a new integrated approach to control cystic echinococcosis in Morocco: Vaccination of sheep and anthelmintic treatment of dogs

Cystic echinococcosis (CE) or hydatidosis is a common parasitic disease worldwide, especially in poor and developing countries. In Morocco, CE is a major zoonosis, despite the implementation of a national control program since 2007. Therefore, in 2016, a field trial that associates the EG95 vaccine (lambs) and anthelmintic treatment (dogs) was started in the Mid Atlas, the most endemic region in Morocco, with preliminary positive results. Here, a qualitative approach was used to analyze the feasibility and social acceptability of this strategy. Fifteen focus group discussions were separately conducted with breeders and with their wives, and forty-two individual interviews were performed with private-sector veterinarians and officers from structures responsible for the CE control program. Recordings were transcribed and analyzed with the R software, using the RQDA package. This qualitative research was validated using the credibility, transferability, dependability and confirmability criteria. This study showed that the professionals' views on sheep vaccination and anthelmintic treatment were divided between acceptability and concerns. Conversely, breeders and their wives highlighted the issue of the costs of procedures the utility of which was not immediately clear to them. All participants proposed solutions to improve this strategy, and also stressed the lack of education on CE. By bringing together the views of the communities and the professionals, this study traced the main lines (targeting the different aspects of CE and taking into account the local socio-cultural beliefs) that must be taken into account to ensure the short- and long-term CE control in Morocco.

Using qualitative approaches to explore the challenges of integrated programmes for zoonosis control in developing countries: Example of hydatidosis control in Morocco

Cystic echinococcosis, rabies and bovine tuberculosis are major neglected zoonoses in many developing countries, including Morocco. A common step in their control strategies is the management of slaughterhouses and/or the control of dog populations. This study used a qualitative approach to identify the barriers to the implementation of the cystic echinococcosis control programme in Morocco that focused on slaughterhouses and dog control. This approach could be used to understand the causes leading to the defective management of other zoonoses, and to go beyond the often-invoked 'lack of means' reason to explain failure in disease control in the Global South. Specifically, slaughterhouse observation and in-depth individual interviews with stakeholders involved in the cystic echinococcosis control programme were carried out in five Moroccan regions (Rabat-Sale-Kenitra, Mellal-Khenifra, Sous-Masaa, Laayoune-Sakia El Hamra and Guelmim-Oued Noun) for 3 years (from 2014 to 2016). Interviews (n = 81) were with agents responsible of the services managing slaughterhouses and dog population control, and also with slaughterers. Recordings were fully transcribed and narratives were analysed with the RQDA package and the R software. Triangulations and the criteria proposed by Guba and Lincon were used to assess the approach validity. This analysis revealed that in addition to 'lack of means', zoonosis control programmes can be hindered by overlapping authority/functions among the involved authorities, conflicts of interest, lack of proper training and professional practices. Zoonosis control requires the commitment of all structures, the establishment of a national and inter-regional strategy, and the updating of the legislative arsenal.

Immunological responses and potency of the EG95NC- recombinant sheep vaccine against cystic echinococcosis

Cystic echinococcosis (CE) is a zoonotic disease caused by the cestode parasite Echinococcus granulosus. The disease has an important impact on human health as well as economic costs including the cost of treatment as well as loss of productivity for the livestock industry. In many parts of the world where the disease is endemic, sheep and other livestock play an important role in the parasite's transmission. A vaccine to protect livestock against CE can be effective in reducing transmission and economic costs of the disease. A recombinant antigen vaccine has been developed against infection with E. granulosus (EG95) which could potentially be used to reduce the level of E. granulosus transmission and decrease the incidence of human infections. Further development of the EG95 recombinant vaccine as a combined product with clostridial vaccine antigens is one potential strategy which could improve application of the hydatid vaccine by providing an indirect economic incentive to livestock owners to vaccinate against CE. In this study we investigated the efficacy of the EG95 recombinant vaccine produced in Morocco by vaccination of sheep, including a combined vaccine incorporating EG95 and clostridia antigens. Vaccination with EG95 either as a monovalent vaccine or combined with clostridia antigens, protected sheep against a challenge infection with E. granulosus eggs and induced a strong, long lasting, and specific antibody response against the EG95 antigen.

Prevalence of Intestinal Helminth Infections in Dogs and Two Species of Wild Animals from Samarkand Region of Uzbekistan

This study aimed to determine the prevalence of intestinal helminth parasitic infections and associated risk factors for the human infection among the people of Samarkand, Uzbekistan. Infection status of helminths including Echinococcus granulosus was surveyed in domestic and wild animals from 4 sites in the Samarkand region, Uzbekistan during 2015-2018. Fecal samples of each animal were examined with the formalin-ether sedimentation technique and the recovery of intestinal helminths was performed with naked eyes and a stereomicroscope in total 1,761 animals (1,755 dogs, 1 golden jackal, and 5 Corsac foxes). Total 658 adult worms of E. granulosus were detected in 28 (1.6%) dogs and 1 (100%) golden jackal. More than 6 species of helminths, i.e., Taenia hydatigena, Dipylidium caninum, Diplopylidium nolleri, Mesocestoides lineatus, Toxocara canis, and Trichuris vulpis, were found from 18 (1.0%) dogs. Six (T. hydatigena, Toxascaris leonina, Alaria alata, Uncinaria stenocephala, D. caninum, and M. lineatus) and 2 (D. nolleri and M. lineatus) species of helminths were also detected from 5 Corsac foxes and 1 golden jackal, respectively. Taeniid eggs were found in 2 (20%) out of 10 soil samples. In the present study, it was confirmed that the prevalences of helminths including E. granulosus are not so high in domestic and wild animals. Nevertheless, the awareness on the zoonotic helminth infections should be continuously maintained in Uzbekistan for the prevention of human infection.

In vitro effects of Blepharocalyx salicifolius (H.B.K.) O. Berg on the viability of Echinococcus ortleppi protoscoleces

Scolicidal agents are important in the treatment of cystic echinococcosis. This study evaluated the scolicidal activity of the plant Blepharocalyx salicifolius (H.B.K.) Berg against Echinococcus ortleppi protoscoleces. The parasite species was identified by amplifying a fragment of the gene cytochrome c oxidase subunit 1 (COX 1). B. salicifolius crude extract at concentrations of 100, 200, 300 and 400 mg/mL was analyzed at different times (5, 10, 15, 30, 45 and 60 min). N-butanol and ethyl acetate fractions (100 and 200 mg/ mL) were also analyzed at 5, 10, 15 and 30 min. Both fractions showed 100% scolicidal activity at the concentration of 200 mg/mL at 5 min. Gallic acid, identified as the major compound of the ethyl acetate fraction- was responsible for the observed scolicidal activity. The results showed that crude extract and fractions of B. salicifolius have scolicidal effect against E. ortleppi protoscoleces.

Analysis of hospital records of children with hydatid cyst in south of Iran

The clinical manifestations of hydatidosis are various and related to anatomic location. Defining frequent symptoms and signs of the disease is imperative for early management of it. The aim of this report was to analyse the clinical features of infected children with hydatid cysts located in different organs. In this study, medical charts of 57 children between 3 and 16 years of age with hydatid cyst admitted to Pediatric Wards of Nemazee Hospital were evaluated over a 12 year period (from 2003 to 2014, prospectively). All the epidemiologic, clinical, paraclinical and therapeutic data were collected. The frequencies of hydatidosis in males and females were 42.1 and 56.1%, respectively. Hydatid cysts were found in the liver and lungs in 59.6 and 33.3% patients respectively and 2 patients had an asymptomatic cyst in the heart with concomitant liver and lung cysts. The right upper quadrant pain (100%) was the most common symptom in the liver cysts. Phlegm (78.9%), Dyspnea (57.9%), acute (47.4%) and chronic cough (47.4%) were mostly seen in lung hydatid cysts. Some symptoms such as fever (68.4%) and weakness (59.6%) were the most common presenting symptoms in both groups. All children were treated through surgical approaches plus medical treatment. In the present report, liver was the most common site of involvement in children. Liver hydatidosis should be considered in children with upper quadrant pain and pulmonary hydatidosis in children complaining of phlegm and dyspnoea.

Prevalence of cystic echinococcosis in Iran: a systematic review and meta-analysis

As a significant zoonosis, cystic echinococcosis (CE) is endemic in some parts of the world, such as the Middle East. There are studies on the prevalence of this infection in animal and human reservoirs in Iran; hence, we conducted this meta-analysis to elucidate the prevalence of CE in Iran. English (PubMed, Scopus, Web of Science, Science Direct and Google Scholar) and Persian (Magiran, Iran Medex, Iran Doc and SID) databases were explored. In the case of definitive, animal and human intermediate hosts, 37, 90 and 33 studies, respectively, have been included in the current review from January 1990 to December 2015. According to outcomes of the heterogeneity test, either Der Simonian and Laird's random-effects method or Mantel–Haenszel's fixed-effects method were employed to pool the estimations. The pooled prevalence ofEchinococcus granulosusinfection in definitive hosts was calculated as 23.6% (95% confidence interval (CI) = 17.6–30.1%). The weighted prevalence of animal and human hydatidosis was calculated as 15.6% (95% CI = 14.2–17.1%) and 4.2% (95% CI = 3.0–5.5%), respectively. Meanwhile, most cases of human hydatidosis were in southern Iran, with a prevalence of 5.8% (3.2–9.2%). In terms of human hydatidosis, more infections were found in rural regions, and mostly in female individuals. Egger's regression test revealed publication bias, with a remarkable impact on total prevalence of the infection in animal intermediate hosts (P< 0.001), while it was not significant in human hosts (P= 0.4) and definitive hosts (P= 0.3). According to the weighted estimated prevalence of cystic echinococcosis and its financial burden, implementing appropriate control programmes should be compulsory to decrease the burden of the disease in Iran.

Echinococcosis: Control and Prevention

Human cystic echinococcosis (CE) has been eliminated or significantly reduced as a public health problem in several previously highly endemic regions. This has been achieved by the long-term application of prevention and control measures primarily targeted to deworming dogs, health education, meat inspection, and effective surveillance in livestock and human populations. Human CE, however, remains a serious neglected zoonotic disease in many resource-poor pastoral regions. The incidence of human alveolar echinococcosis (AE) has increased in continental Europe and is a major public health problem in parts of Eurasia. Better understanding of wildlife ecology for fox and small mammal hosts has enabled targeted anthelmintic baiting of fox populations and development of spatially explicit models to predict population dynamics for key intermediate host species and human AE risk in endemic landscapes. Challenges that remain for echinococcosis control include effective intervention in resource-poor communities, better availability of surveillance tools, optimal application of livestock vaccination, and management and ecology of dog and wildlife host populations.

Protoscolicidal effects of chenodeoxycholic acid on protoscoleces of Echinococcus granulosus

Dissemination of protoscoleces-rich fluid during surgical operation for cystic echinococcosis is a major cause of its recurrence. Instillation of a scolicidal agent into hydatid cysts to reduce the risk of spillage of viable protoscoleces is an integral part of the surgical technique employed by many surgeons. In this study, the protoscolicidal effect of chenodeoxycholic acid (CDCA) was investigated. Freshly isolated protoscoleces were subjected to CDCA treatment (500, 1000, 2000, and 3000 μmol/L), and the effects on protoscoleces were investigated with the help of 0.1% eosin staining, electron microscopy, and colorimetric assay of caspase-3 like activity. Dose-dependent mortality of Echinococcus granulosus protoscoleces was observed within a few days of CDCA treatment. The treated protoscoleces showed loss of viability, and morphological changes such as contraction of the soma region, formation of blebs, rostellar disorganization, loss of hooks, destruction of microtriches, and formation of vesicles, lipid droplets, and lamellar bodies. Apoptosis was evident in the treated protoscoleces, as compared to the control group, which were cultivated for nearly 3 months. Our study indicates a therapeutic potential for CDCA as a protoscolicidal agent against E. granulosus. However, further studies are needed to test the long-term effects of CDCA in animal models.

Role of soluble programmed death-1 (sPD-1) and sPD-ligand 1 in patients with cystic echinococcosis

The programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) signaling pathway is a negative regulatory mechanism that inhibits T cell proliferation and cytokine production. Soluble PD-1 (sPD-1) and soluble PD-L1 (sPD-L1), are also involved in regulation of the PD-1/PD-L1 signaling pathway. In the present study, the expression levels of sPD-1 and sPD-L1, as well as those of T helper (Th)1 [including interleukin (IL)-2 and interferon gamma], Th2 (including IL-4, IL-6 and IL-10) and Th17 (including interleukin 17) cell cytokines, were measured in the sera of patients with cystic echinococcosis (CE). Measurements were performed prior to and following after surgery and treatment with cyclic albendazole to investigate the effects of sPD-1 and sPD-L1 in patients with CE. Cytokine expression levels were measured using cytokine bead array and the expression levels of sPD-1 and sPD-L1 were measured using ELISA. In addition, in vitro stimulation was used to detect whether sPD-L1 has a negative regulatory effect on cytokine secretion or homeostasis. The present study observed significantly higher levels of sPD-L1 in patients with CE compared with healthy controls. Significantly elevated levels of Th2 cytokines in the sera of patients with CE were also observed. The results also suggest that there is an imbalanced expression of Th1 and Th2 cells during CE. In addition, it was demonstrated that sPD-1 and sPD-L1 are regulatory factors to the PD-1/PD-L1 signaling pathway, each having opposite effect, suggesting that they regulate the immune response to CE infection by creating a dynamic balance. In conclusion, sPD-L1 may play an important role in maintaining homeostasis in hosts with CE.

Cerebral intraventricular echinococcosis in an adult

Background:

Echinococcosis in humans occurs as a result of infection by the larval stages of taeniid cestodes of the genus echinococcus. Intracranial hydatid cysts usually develop at an intraparenchymal site. Hydatid cyst within the cerebral ventricle is quite unusual.

Methods:

We reviewed the literature on adult intraventricular hydatid cyst and found case reports mainly in children with an only handful of cases in adults. We reported a rare case of cerebral intraventricular (left lateral ventricle) hydatid cyst in a 21-year-old adult female.

Results:

Although cerebral hydatid cysts are most commonly seen in children and young adults cerebral intraventricular hydatid cyst are comparatively rarer in adults.

Conclusion:

The possibility of infection with Echinococcus granulosus should be included in the differential diagnosis of raised intracranial hypertension in patients from endemic areas.

Efficacy of Berberis vulgaris aqueous extract on viability of Echinococcus granulosus protoscolices

BACKGROUND

Surgery is one of the best choices for the treatment of hydatidosis. To prevent the secondary infection, it is essential to use effective scolicidal agents during surgery for hydatid cyst. Up to now, no effective and safe agent has been identified for this purpose. Berberis vulgaris called "Zereshk" in Persian has been traditionally used as a herbal remedy for the treatment of different complaints. Many studies have shown that Berberis vulgaris has antibacterial, antifungal, and antiparasitic effects.

METHODS

In our study, the scolicidal effect of barberry with different concentrations (0.5, 1, 2, and 4 mg/ml diluted form) and at different exposure times (5, 15, and 30 min) was evaluated. For this purpose, we obtained sheep liver hydatid cysts from a slaughterhouse. Viability of protoscolices was assessed by 0.1% Eosin staining. Normal saline and hypertonic saline were used as negative and positive controls, respectively.

RESULTS

All the different concentrations of Berberis vulgaris aqueous extracts had scolicidal effect. The strongest effect was observed to be in 4 mg/ml concentration, which acted as positive control. Scolicidal activity of 2 mg/ml dilution was close to 4 mg/ml and the least scolicidal effect was observed in 0.5 mg/ml. Scolicidal activity of extracts had significant differentiation between 5th and 30th min of exposure.

CONCLUSION

The scolicidal activity was very effective in low concentration (4 mg/ml) and short exposure time (5 min). Therefore, after being examined in vivo and additional experiments, it may be used as a suitable and effective scolicidal in surgery.

The destructive effects of high-intensity focused ultrasound on hydatid cysts enhanced by ultrasound contrast agent and superabsorbent polymer alone or in combination

Cystic echinococcosis, caused by the metacestode stage of Echincoccus granulosus, remains endemic in many regions around the world. The present work evaluated whether or not a superabsorbent polymer (SAP) and ultrasound contrast agent (UCA) alone or in combination could enhance damage efficacy of high-intensity focused ultrasound (HIFU) on hydatid cysts in vitro. HIFU of 100 W acoustic power, with the aid of 0.1 ml UCA and 0.1 g SAP alone or in combination, was used to ablate hydatid cysts in vitro. The comparison of ultrasound image for each layer of hydatid cyst before and after HIFU ablation was made immediately, and the protoscolices of the cysts were stained by eosin exclusion assay, and the structures of protoscolices were observed by light microscopy. To understand the destructive effects of HIFU, the pathological changes in cyst walls of hydatid cyst ablated with HIFU were examined. The results demonstrated that HIFU had some lethal effect on hydatid cysts: echo enhancement of ultrasound image, increase of mortality rate of protoscolices, serious structural damage of protoscolices, and complete destruction or even disappearance of laminated layer and germinal layer was observed in the group of HIFU combined with UCA and SAP alone or in combination. It was found that the destructive effect of HIFU aided with a combination of UCA and SAP to hydatid cysts was more effective than that of HIFU just aided with UCA or SAP alone. These results suggested that UCA and SAP might be used as a HIFU enhancing agent to improve the efficacy of HIFU ablation to hydatid cysts, which could be a possible therapeutic option for cystic echinococcosis.

Human cystic echinococcosis: epidemiologic, zoonotic, clinical, diagnostic and therapeutic aspects

This review represents an updated scenario on the transmission cycle, epidemiology, clinical features and pathogenicity, diagnosis and treatment, and prevention and control measures of a cestode parasite Echincoccus granulosus (E. granulosus) infection causing cystic echinococcosis (CE) in humans. Human CE is a serious life-threatening neglected zoonotic disease that occurs in both developing and developed countries, and is recognized as a major public health problem. The life cycle of E. granulosus involves a definitive host (dogs and other canids) for the adult E. granulosus that resides in the intestine, and an intermediate host (sheep and other herbivores) for the tissue-invading metacestode (larval) stage. Humans are only incidentally infected; since the completion of the life cycle of E. granulosus depends on carnivores feeding on herbivores bearing hydatid cysts with viable protoscoleces, humans represent usually the dead end for the parasite. On ingestion of E. granulosus eggs, hydatid cysts are formed mostly in liver and lungs, and occasionally in other organs of human body, which are considered as uncommon sites of localization of hydatid cysts. The diagnosis of extrahepatic echinococcal disease is more accurate today because of the availability of new imaging techniques, and the current treatments include surgery and percutaneous drainage, and chemotherapy (albendazole and mebendazole). But, the wild animals that involve in sylvatic cycle may overlap and interact with the domestic sheep-dog cycle, and thus complicating the control efforts. The updated facts and phenomena regarding human and animal CE presented herein are due to the web search of SCI and non-SCI journals.

Host-parasite relationship in cystic echinococcosis: an evolving story

The larval stage of Echinococcus granulosus causes cystic echinococcosis, a neglected infectious disease that constitutes a major public health problem in developing countries. Despite being under constant barrage by the immune system, E. granulosus modulates antiparasite immune responses and persists in the human hosts with detectable humoral and cellular responses against the parasite. In vitro and in vivo immunological approaches, together with molecular biology and immunoproteomic technologies, provided us exciting insights into the mechanisms involved in the initiation of E. granulosus infection and the consequent induction and regulation of the immune response. Although the last decade has clarified many aspects of host-parasite relationship in human cystic echinococcosis, establishing the full mechanisms that cause the disease requires more studies. Here, we review some of the recent developments and discuss new avenues in this evolving story of E. granulosus infection in man.

Hydatid disease of the skull base: report of three cases and a literature review

We report three cases of hydatid disease of the skull base and the treatment thereof. The first involved the anterior cranial fossa and paranasal sinuses. The second was located in the infratemporal fossa. The last involved the temporal bone and posterior cranial fossa. Hydatid disease is endemic in many parts of the world where livestock farming is practiced and is highly endemic in sub-Saharan Africa. Although hydatid disease of the head and neck is rare, it should be considered in the differential diagnosis of cystic disease in the head and neck region. Of the three forms of hydatid disease, Echinococcus granulosis is most common and gives rise to cystic hydatid disease. Most hydatid cysts are "silent," but become clinically apparent because of their mass effects, when they rupture, or if they become superinfected. Computed tomography scanning and magnetic resonance imaging are the best diagnostic tools. Hydatid disease can be successfully treated by a combination of surgery and chemotherapy.

Zoonotic helminth infections of humans: echinococcosis, cysticercosis and fascioliasis

PURPOSE OF REVIEW

Tissue parasites of humans are still prevalent in most regions of the world, and are also seen more frequently in developed countries due to increasing travel patterns. In particular, Echinococcus infections still account for hepatic and pulmonary pathology, cysticercosis is a major cause of seizures and epilepsy, and fascioliasis also causes significant liver pathology. This review summarizes current knowledge on clinical and epidemiologic aspects of zoonotic disease caused by tissue helminths.

RECENT FINDINGS

Tissue helminth infections remain as a public health concern. Recent research has provided new insights into clinical disease in humans and improved methods for diagnosis, treatment and control, arising mostly from the application of new techniques for immune and molecular diagnosis, availability of data from controlled trials, and development of new vaccines. Specific antiparasitic therapies are now better characterized, and new control tools are available.

SUMMARY

Recent research has provided new diagnostic technologies applicable to diagnosis, treatment and control, but effective interventions to reduce transmission are rarely applied. Despite some progress in their control, these zoonoses continue to be a major public health problem in many regions both in developing countries and in some more developed ones.

Prevention and control of cystic echinococcosis

Human cystic echinococcosis (hydatid disease) continues to be a substantial cause of morbidity and mortality in many parts of the world. Elimination is difficult to obtain and it is estimated that, using current control options, achieving such a goal will take around 20 years of sustained efforts. Since the introduction of current (and past) hydatid control campaigns, there have been clear technological improvements made in the diagnosis and treatment of human and animal cystic echinococcosis, the diagnosis of canine echinococcosis, and the genetic characterisation of strains and vaccination against Echinococcus granulosus in animals. Incorporation of these new measures could increase the efficiency of hydatid control programmes, potentially reducing the time required to achieve effective prevention of disease transmission to as little as 5-10 years.