Endless story of a spinal column hydatid cyst disease: A case report

We describe a case of multifocal relapsing hydatid cyst following multilevel thoracic corpectomy and 360° instrumentation surgery. A 41-year-old male patient presented with cord compression and paraplegia due to a multiseptated cystic lesion at T10-11 level. The cyst was excised with a combined anterior and posterior approach and 360° stabilization was performed. The patient received albendazole for 1 year after the surgery. The patient presented with paraparesis 5 years after the surgery. Cystic lesions between C2-T1 and T10-11 were detected on the spinal MRI and the patient was operated with removal of the lesions on both levels and adjuvant local 20% hypertonic saline application. The patient received albendazole for the postoperative 6 months. After 3 months from the surgery, the patient's paraparesis recovered. There was no recurrence after 2 years from the last surgery.

Antigen B from Echinococcus granulosus enters mammalian cells by endocytic pathways

Background

Cystic hydatid disease is a zoonosis caused by the larval stage (hydatid) of Echinococcus granulosus (Cestoda, Taeniidae). The hydatid develops in the viscera of intermediate host as a unilocular structure filled by the hydatid fluid, which contains parasitic excretory/secretory products. The lipoprotein Antigen B (AgB) is the major component of E. granulosus metacestode hydatid fluid. Functionally, AgB has been implicated in immunomodulation and lipid transport. However, the mechanisms underlying AgB functions are not completely known.

Methodology/Principal findings

In this study, we investigated AgB interactions with different mammalian cell types and the pathways involved in its internalization. AgB uptake was observed in four different cell lines, NIH-3T3, A549, J774 and RH. Inhibition of caveolae/raft-mediated endocytosis causes about 50 and 69% decrease in AgB internalization by RH and A549 cells, respectively. Interestingly, AgB colocalized with the raft endocytic marker, but also showed a partial colocalization with the clathrin endocytic marker. Finally, AgB colocalized with an endolysosomal tracker, providing evidence for a possible AgB destination after endocytosis.

Conclusions/Significance

The results indicate that caveolae/raft-mediated endocytosis is the main route to AgB internalization, and that a clathrin-mediated entry may also occur at a lower frequency. A possible fate for AgB after endocytosis seems to be the endolysosomal system. Cellular internalization and further access to subcellular compartments could be a requirement for AgB functions as a lipid carrier and/or immunomodulatory molecule, contributing to create a more permissive microenvironment to metacestode development and survival.

Antigen B (AgB) is an oligomeric lipoprotein highly abundant in Echinococcus granulosus hydatid fluid. AgB has already been characterized as an immunomodulatory protein, capable of inducing a permissive immune response to parasite development. Also, an important role in lipid acquisition is attributed to AgB, because it has been found associated to different classes of host lipids. However, the mechanisms of interaction employed by AgB to perform its functions remain undetermined. In this study, we demonstrate that mammalian cells are able to internalize E. granulosus AgB in culture and found that specific mechanisms of endocytosis are involved. Our results extend the understanding of AgB biological role indicating cellular internalization as a mechanism of interaction, which in turn, may represent a target to intervention.

Alveolar echinococcosis in the head of pancreas: A case report

RATIONALE

Pancreatic alveolar echinococcosis (AE) is an exceptionally rare disease; no more than 10 cases have been published to date. It is characterized as extensive local tissue infringement and destruction; thus, extended surgical resection, such as duodenopancreatectomy, is often needed to obtain a negative resection margin so as to improve the long-term outcome and prognosis.

PATIENT CONCERNS

A middle-aged Tibetan man was admitted due to a 16-year history of recurrent pain in the right upper abdomen. Magnetic resonance imaging scan showed a cystic lesion in the VI segment of his liver and several cystic lesions in the head of pancreas.

DIAGNOSES

Pancreatic AE.

INTERVENTIONS

The patient adopted a preserved surgery of partial cystectomy and completely removing the content of the cyst and then soaking by hypertonic saline combined with adjuvant medical therapy of albendazole.

OUTCOMES

The patient was monitored on a regular basis at the outpatient department; the patient is still alive and has already survived 8 years till now.

LESSONS

A preserved surgery combined with adjuvant medical therapy of albendazole can also contribute to a good survival outcome for AE located at the head of pancreas.

[(EXPERIENCE WITH ALBENDAZOLE TREATMENT IN CHILDREN WITH CYSTIC ECHINOCOCCOSIS)]

The tolerability and efficiency of specific chemotherapy with albendazole were analyzed in 18 patients with cystic echinococcosis at various sites. The most common complication of albendazole treatment was its hepatotoxic effect. Al- bendazole chemotherapy during at least its 3 cycles was observed to be highly effective in preventing recurrent echinococ- cosis in children. If there were small-sized hydatid cysts in the liver and lung, there was a reduction in their number and sizes after 4-5 albendazole treatment cycles.

Atypical Presentation of Hydatid Cyst in the Thigh

To emphasise that hydatid cyst disease can present as a soft tissue mass even in an unusual site like the thigh, we report the case of a 21-year male patient who presented to Surgical Unit IV, Civil Hospital, Karachi, with a slow growing cystic swelling on the medial aspect of the left thigh. Based on serology and imaging, a diagnosis of solitary subcutaneous hydatid cyst thigh was made and cystopericystectomy was performed. Histopathology confirmed the diagnosis. Up to three months postoperatively, there was no recurrence. In the absence of visceral organ involvement, this is the first reported case of primary subcutaneous hydatid disease of the thigh in Pakistan.

Laparoscopic Approach for Management of Hydatid Cyst of Liver

BACKGROUND

Laparoscopy surgery trials are small and unconvincing at present and are limited to higher centers. The objective of the study is to determine the clinical features, prevalence of site of hydatid cyst and complications of this modality of this treatment.

METHODS

A cross sectional study was carried out in all patients with one or two hepatic hydatid cyst who underwent laparoscopic management in KMCTH from January 2013 to March 2015 were included in the study. Aspiration, deroofing and evacuation of the hydatid cyst were done.

RESULTS

Twenty six patients underwent laparoscopic management for liver hydatid cysts. Males were seven (65.38%) and females were 9(34.61%).The mean age was 35.5±13.1 years (range 21-55years.) The commonest complaint was pain and discomfort in 13(50%) patients and lump in 6(13.06%) patients. Twenty four (92.3%) patients were successfully treated with laparoscopic approach. Two (7.69%) patients had to be converted to laparotomy because of dense adhesions and bleeding. Mean operation time was 43.6±10.6 minutes. Two (7.69%) patients had port site infection. One (3.84%) patient had bile leak and no recurrence and mortality in our series.

CONCLUSIONS

Laparoscopic management of liver hydatid cyst was safe and effective in selective group of patients in equipped hospital.

Isolated renal and retroperitoneal hydatid cysts: a report of 23 cases

Isolated extrarenal retroperitoneal and renal echinococcal cysts are rare manifestations of hydatid disease. We report 23 cases of renal and other retroperitoneal hydatid cysts diagnosed and treated in our clinic. Flank pain, abdominal mass and non-specific symptoms such as nausea and vomiting were the major symptoms. Indirect haemagglutination test was positive in 18 cases and eosinophilia in four cases. Among imaging studies computerized tomography was the most valuable diagnostic examination. A high index of suspicion is needed for preoperative diagnosis of hydatid disease of kidney and retroperitoneum.

A RARE CASE OF HYDATID CYST DISEASE OF THE BREAST: A CASE REPORT AND REVIEW OF LITERATURE

Hydatid cyst of the breast is extremely rare even in endemic areas and it only accounts for 0.27% of all hydatid cyst disease cases. It can either be a primary site or part of a disseminated hydatidosis. Surgery remains to be a treatment of choice. Only few reports are published in the literatures and most of the reported cases have been diagnosed postoperatively as it is not easy to reach at a definitive diagnosis with clinical examination and radiological investigations only. This is a case of an isolated hydatid cyst of breast in an 18-year old woman from the Amhara region, Ethiopia. She presented with left breast painless lump of 5 years duration and a correct pre-operative diagnosed was made by fine needle aspiration cytology, then confirmed after surgery. We believe this disease should be included in the differential diagnosis of benign breast lumps especially in endemic areas.

Lesson of the month 2: Cough and right hypochondrial discomfort

Cystic echinococcosis, commonly known as hydatid disease, is caused by the larval stage of the tapeworm Echinococcus granulosus. Humans are an accidental host to this rare disease in the UK, with around 10-20 new cases reported each year. Once suspected, the diagnosis is confirmed through a combination of relevant history, imaging studies and serological testing. This lesson presents a case of hydatid disease and outlines the significant management issues when cysts rupture and the disease becomes disseminated.

Primary pelvic hydatid cyst an unusual cause of cystic adnexal image (mass)

Hydatid cyst is a parasitic human infection which is endemic in North Africa. It is more frequently localized in the liver and the lung. Involvement of others sites is usually secondary to these primary localizations. We report 2 exceptional cases of primary pelvic hydatid cyst diagnosed respectively in a 37-year-old and in a 48-year-old women. These cases will focus on the different characteristics of the infection, and the benefit of including epidemiologic arguments in using the diagnostical approach of adnexal masses.

[Immunorehabilitation in patients with paecilomycosis-complicated echinococcosis and asthma]

Paecilomycosis is a new type of systemic mycosis caused by different species of fungi of the genus Paecilomyces. Paecilomycosis-complicated echinococcosis and asthma run a severe course. A complication of mycosis is accompanied by secondary immunodeficiency. A good result was obtained in the treatment of ill children by using the fungicide diflucan and the immunomodulator polyoxidonium. In the examinees with paecilomycosis-complicated echinococcosis, secondary immunodeficiency was characterized by a statistical significant reduction in the blood levels of the lymphoid cells CD3+, CD4+, CD8+, CD16+, CD21+, by phagocytosis, a decrease in its quantitative parameters, and an increase in the counts of immunoglobulins and circulating immunocomplexes. To normalize the immune status in patients with paecilomycosis-complicated echinococcosis, it is expedient to postsurgicallyuse fungicides, such as nizoral, diflucan, orungal, mycosyst, and the immunomodulators polyoxidonium and irillen.

[Pathophysiology and immune response in sheep experimentally infected with Echinococcus granulosus]

The immune response to Echinococcus granulosus in sheep has not been extensively investigated. The objective of this study was to increase the information on the physiopathology of E. granulosus and the immune response elicited in sheep. Animals were experimentally inoculated with three different doses of E. granulosus eggs and the immune response was evaluated over 500 days using enzyme immunoassay with three antigenic preparations: total hydatid fluid, purified fraction of hydatid fluid and purified lipoprotein fraction. Sheep were slaughtered at different intervals to observe the macroscopic and microscopic development of the parasite. Immune response was detected at 10 days and was maintained throughout the observation period, being initially proportional to the load of inoculated eggs and then decreasing over time. Fertile cysts were identified 10 months after inoculation and live onchosphere 500 days after inoculation. Antibody response to E. granulosus in sheep preceded hydatid fluid formation and was generated by the mobility of the onchosphere. Early histological identification of fertile cysts indicates that feeding dogs with viscera of young sheep can produce cycles of infection. Furthermore, the presence of live onchosphere in the liver here found contributes to a better knowledge of the pathogenesis of this disease it could be hypothetically considered as a cause for the repeated surgeries necessary in man after the extirpation of a hydatid cyst.

Echinococcosis

Echinococcosis is a human disease caused by the larval form of Taenia echinococcus, which lives in the gut of the dog, wild canides and other carnivorous animals which represent the definitive hosts and involves as intermediate hosts both domestic and wild animals. Humans become accidental intermediate hosts by ingesting Taenia eggs. The main species pathogenic for man are E granulosus causing cystic echinococcosis with worldwide distribution and endemic in sheep and cattle breeding countries, and E multilocularis causing alveolar echinococcosis, with preferential distribution in the northern hemisphere. After ingestion of contaminated food, hexacanth embryos migrate by the portal system to liver and later lung, brain and other tissues. Symptoms are related to both cyst location and size. E granulosus infection of the central nervous system (CNS) may be primary or secondary and has been estimated to be low (2%). Sharply demarcated, spherical and intraparenchymal, cysts may reach a large size causing neurological symptoms. Spilling of cyst fluid due to trauma or surgery may trigger anaphylaxis as well as disseminated infection. Host reaction is minimal in the brain but a foreign giant cell reaction may develop. E multilocularis develops within the liver as a rapid invasive pseudomalignant growth and may metastasize to the CNS, where estimated incidence reaches 5%. Hydatid antigens induce an immune reaction in the host which is helpful for the diagnosis. DNA probes and PCR may be applied to differentiate between Echinococcus spp. Although the host develops an immunological protection from reinfection, the parasite evades host immune attack. A wide range of evasion mechanisms have been advanced, including a barrier for host cells due to hydatid cyst laminated cuticle, polyclonal activation of lymphocytes by parasite soluble antigens, and depression of host cell immune responses. Chronic stimulation of the host by cyst fluid antigens leads to increased specific IgG4 production, which might act as blocking antibodies against anaphlaxis suggestive of host response immunomodulation.

Hydatid disease in Iranian children

BACKGROUND AND PURPOSE

Hydatidosis is a major public health problem that can cause significant morbidity and mortality; however, it is possible to control and even eradicate the disease. This study was carried out to investigate pediatric hydatidosis in Iran.

METHODS

Data were collected from the records of 31 patients admitted to the Children Medical Center Hospital in Tehran, Iran, with hydatidosis from 1995 to 2005. Data collected included demographic data, and information on clinical manifestations, type and site of cysts, laboratory results, and therapeutic procedures employed.

RESULTS

Eighteen patients (58%) were male and 13 (42%) female. The mean age of patients was 8.3 years. On serological study, almost all patients (96%) were found to be positive for hydatidosis. Sixteen cases (52%) had a history of contact with dogs or sheep, and 6 (19%) had parents who were farmers. Cysts were found in the lungs and livers of 24 (77%) and 15 cases (48%), respectively, with 8 cases (26%) having simultaneous liver and lung cysts. Three patients (10%) had multiorgan involvement. The significant clinical manifestations of pulmonary hydatid cysts were cough (92%), fever (83%), and dyspnea (46%). Fever (100%) and hepatomegaly (87%) were the most common symptoms in cases with hepatic cysts. All patients underwent surgery and treatment with albendazole, and recurrence was observed in 2 cases (6%).

CONCLUSIONS

Hydatidosis is endemic throughout Iran. Thus, there are reasonable grounds to suspect hydatid cyst infection in patients presenting with cysts in any organ with either an appropriate residential or travel history or in the case of children, with parents in occupations such as sheep raising.

Management of echinococcosis

Cystic echinococcosis is a zoonosis caused by larval forms of the tapeworm Echinococcus granulosus and transmitted by dogs. In humans, the disease is characterized by slowly growing cyst commonly occurring in liver and lungs. Clinical features of hepatic hydatid cyst are mainly right upper quadrant pain, feeling of lump and enlarged tender liver. The cyst may be complicated by infection or rupture and may lead to anaphylactic reaction. Ultrasonography supported by serology is the main diagnostic modality. Treatment of univesicular cyst is predominantly medical or percutaneous. Percutaneous treatment (PAIR) is safe and effective and complications are infrequent. For multivesicular and complicated cyst surgery remains the mainstay of treatment.

Long-term surgical outcome in patients with intracranial hydatid cyst

BACKGROUND

Cerebral hydatid cysts account for up to 3.6% of all intracranial space-occupying lesions, in endemic countries. The vast majority of patients affected are children. Computed tomography (CT) and magnetic resonance imaging (MRI) have greatly contributed to a more accurate diagnosis of hydatids. However, correct pre-operative diagnosis still remains quite puzzling. Extirpation of the intact cyst is the treatment of choice, resulting in most cases to a complete recovery.

METHOD

In our retrospective study, we have reviewed 76 cases of intra-cranial hydatid disease operated on in our hospital over a 22 year period. Presenting clinical symptoms and signs and the radiological findings on CT and MRI were documented. Albendazole was given preoperatively to patients with giant (>5 cm) or multiple cysts and postoperatively to all patients. The follow-up period ranged from 12 months to 22 years and the outcome was assessed using the Glasgow Outcome Scale (GOS).

FINDINGS

Sixty seven (95.7%) of our patients were children. Increased intracranial pressure and papilledema were the predominant findings in this group, whereas focal neurological deficits were most prevalent in adults. CT and MRI revealed round cystic lesions, isodense and iso-intense respectively to cerebrospinal fluid (CSF), with no rim enhancement or perifocal edema. Multiple cysts were identified in 3 cases. Extirpation of the cyst without rupture was accomplished in 56 patients (73.7%). Recurrences occurred in 19 patients (25%). 4 patients (5.3%) died within 6 months after surgery; 3 of these patients had multiple cysts and one died shortly after the operation due to anaphylactic shock following intra-operative rupture of the cyst.

CONCLUSION

Long-term follow-up confirms that intracranial hydatid cysts should always be surgically removed without rupture; the outcome remains excellent in these cases. Correct preoperative diagnosis is vital for the successful outcome of surgery. A high index of suspicion is therefore required in endemic areas despite the availability of advanced neuro-imaging. Medical treatment with albendazole seems to be beneficial both pre- and post-operatively. Newer diagnostic methodologies, such as MR spectroscopy and MR diffusion weighted imaging, might lend themselves to the diagnosis of intracranial hydatid cysts.

Cestode parasitic infestation: intracranial and spinal hydatid disease--a clinicopathological study of 29 cases from South India

In developing countries hydatidosis is both a medical and economic problem related to environmental hygiene and healthy veterinary practice. This cestode parasitic infestation, uncommonly involving the nervous system, presents with varied clinical manifestation, at times causing diagnostic dilemmas. Multiple intracranial and spinal hydatidosis is rare. A series of 29 histologically confirmed cases of hydatidosis of neuraxis (21 intracranial and 8 spinal) from South India are presented. Among the 21 cases of intracranial hydatidosis, 12 cases were in pediatric age, while only 1 spinal lesion was noted in a 5-year-old child. The clinical presentation of intracranial lesions was predominantly that of raised intracranial pressure and visual symptoms, while spinal hydatidosis manifested with severe back pain, weakness and sphincter disturbances. The cranial cysts were usually single and uniloculated (12 cases), multiple in 7 and single but multiloculated in 2. In spinal hydatidosis, the cysts are usually multiple and extradural, rare ones being intramedullary and intradural. Based on clinical features and imaging, the differential diagnosis for intracranial lesions were cystic tumors and arachnoid cyst while metastasis and tuberculosis were considered in cases of spinal hydatidosis because of vertebral bony involvement. The majority of the cysts could be surgically resected totally and some were aspirated under control suction and resected. None of the cases had anaphylactic reaction, with no significant post-operative morbidity and no mortality. One intracranial and 2 spinal lesions caused by fertile cysts recurred to undergo repeated surgery.

Usefulness of severe combined immunodeficiency (scid) and inbred mice for studies of cysticercosis and echinococcosis

The topics in this review are the usefulness of immunodeficient and inbred mice for studies of developmental biology, drug efficacy and host specificity in cysticercosis and echinococcosis. In non-obese diabetic severe combined immunodeficiency (NOD/Shi-scid) mice of both sexes, in vitro hatched oncospheres of all three human taeniid species (Taenia solium, Taenia saginata and Taenia asiatica) developed into cysticerci comparable to or bigger than those developed in their known intermediate host animals, whereas only females were susceptible to these infections in other scid mice of BALB/c, C57BL or C.B-17 inbred strains. Detailed morphological observation from post-oncospheral to cysticercus developmental stages is expected to be easy when we use NOD/Shi-scid mice experimentally inoculated with in vitro hatched oncospheres. Metacestocidal effect of oxfendazole was evaluated in NOD/Shi-scid mice experimentally inoculated with oncospheres of T. solium. In Echinococcus multilocularis infection, larval tissue proliferated without induction of inflammatory host responses in scid mice, thus facilitating isolation of the larval vesicles and protoscoleces for biochemical and molecular biological studies. Trans portal inoculation of metacestode tissues resulted in proliferation of secondary echinococcal foci localized exclusively in the liver without metastasis to other tissues or organs. The advantages of a mouse model for Echinococcus granulosus are also described.

Primary hydatid disease of the gallbladder: a rare clinical entity

Hydatid disease is endemic in Greece, and has been known from Hippocrates' time to cause cysts in the liver. We report here three very rare cases of primary gallbladder hydatid disease without prior history or evidence of concurrent disease activity in any other location. To our knowledge, only two previous reports exist, each of one patient suffering from primary gallbladder hydatid disease. Unlike the insidious hydatid cysts of the liver, gallbladder hydatidosis in our patients was associated with early diagnosis, due to gallbladder dysfunction symptoms presenting early in its course. Moreover, the size of gallbladder cysts compared to liver cysts at diagnosis was small (maximal diameter, <5 cm), making total cyst excision along with cholecystectomy feasible for all of our patients. During long-term follow up of the patients (up to 10 years), no disease recurrences were noted. We provide supporting evidence that primary gallbladder hydatidosis presents a different pathophysiological and clinical course, having better prognosis, when compared with the usual liver disease.

Recurrent multiple cardiac hydatidosis

Cardiac hydatid cyst is an uncommon disease. We report on a woman admitted to our clinic with chest pain and palpitations. The ECG showed anterior ischemia, and coronary anatomy was normal. The diagnosis was: multiple cardiac hydatid cysts, for which she had undergone surgery 4 years earlier for a 5 x 5 hydatid cyst and treated with albendazole. Despite this, there was a recurrence of multiple cysts. Recurrence of intracavitary hydatid cyst is rare, and surgical treatment of multiple, small cysts remains controversial.

Eighteen-year experience with echinococcosus of the heart: clinical and echocardiographic features in 14 patients

We present a retrospective analysis of clinical symptoms and echocardiographic features in 14 patients having cardiac hydatic cysts and screened during the 18 last years, with surgical correlations in 13. The heart was the sole location of the cyst in six patients. The revealing symptoms were precordial pain (six patients), dyspnea (two patients). A systolic murmur of false pulmonic stenosis was present in three patients. In 13 patients, two-dimensional echocardiographic images of hydatic cysts were those of masses of liquid content with a well-contrasted capsule, which was single in eight patients and multiple in five, one of which had a honeycomb appearance. The mass was solid and calcified in one patient. The outlines of the cysts were particularly sharp on transesophageal echocardiograms (six patients). The cyst size ranged from 1.8 to 11 cm in diameter. Cysts were located in the intramyocardium in 10 patients (left ventricle in four patients, interventricular septum in four patients, right ventricle in two patients), the pericardium in three and the mediatinum in one. There were a Doppler pulmonary valve gradient in three patients. Computed tomography (eight patients) and coronary arteriography (seven patients) have no additional diagnosis value than echocardiography. Nuclear magnetic resonance imaging (three patients) was helpful in determining extracardiac extension of the cysts. Transthoracic and transesophageal two-dimensional echocardiography have a central role in diagnosing cardiac hydatic cysts.

Splenic hydatid cysts in a 20-year-old soldier

Hydatid disease is a parasitic infection of humans and herbivorous animals caused by Echinococcus granulosus. A 20-year-old male soldier from Booshehr province police center was admitted with left upper quadrant pain that began 1 year before admission. Sonography disclosed an echogenic mass measuring 14 x 16 cm near the spleen and kidneys; a computed tomography scan confirmed it as a hypodense mass of the spleen that was 16 x 17 x 18 cm in dimension. Casoni skin test and indirect fluorescent antibody were positive. Through laparatomy, a splenectomy was successfully performed.

Biological, epidemiological, and clinical aspects of echinococcosis, a zoonosis of increasing concern

Echinococcosis in humans is a zoonotic infection caused by larval stages (metacestodes) of cestode species of the genus Echinococcus. Cystic echinococcosis (CE) is caused by Echinococcus granulosus, alveolar echinococcosis (AE) is caused by E. multilocularis, and polycystic forms are caused by either E. vogeli or E. oligarthrus. In untreated cases, AE has a high mortality rate. Although control is essentially feasible, CE remains a considerable health problem in many regions of the northern and southern hemispheres. AE is restricted to the northern hemisphere regions of North America and Eurasia. Recent studies have shown that E. multilocularis, the causative agent of AE, is more widely distributed than previously thought. There are also some hints of an increasing significance of polycystic forms of the disease, which are restricted to Central and South America. Various aspects of human echinococcosis are discussed in this review, including data on the infectivity of genetic variants of E. granulosus to humans, the increasing invasion of cities in Europe and Japan by red foxes, the main definitive hosts of E. multilocularis, and the first demonstration of urban cycles of the parasite. Examples of emergence or reemergence of CE are presented, and the question of potential spreading of E. multilocularis is critically assessed. Furthermore, information is presented on new and improved tools for diagnosing the infection in final hosts (dogs, foxes, and cats) by coproantigen or DNA detection and the application of molecular techniques to epidemiological studies. In the clinical field, the available methods for diagnosing human CE and AE are described and the treatment options are summarized. The development of new chemotherapeutic options for all forms of human echinococcosis remains an urgent requirement. A new option for the control of E. granulosus in the intermediate host population (mainly sheep and cattle) is vaccination. Attempts are made to reduce the prevalence of E. multilocualaris in fox populations by regular baiting with an anthelmintic (praziquantel). Recent data have shown that this control option may be used in restricted areas, for example in cities, with the aim of reducing the infection risk for humans.

Primary spinal extradural hydatid cyst in a child: case report and review of the literature

Spinal hydatid cyst is a rare but serious condition. An 8-year-old boy presented with back pain, progressive weakness and numbness in both legs. Magnetic resonance imaging (MRI) of the lumbar region showed a cystic lesion with regular contour located in extradural space. There was cerebrospinal fluid- (CSF-) like signal intensity on T1- and T2-weighted images. The lesion had excessively compressed the dural sac and caudal roots, and expanded to the L3 and L4 neural foramina. The case was explored with L2, L3, L4 laminectomy and the hydatid cyst was removed totally. The clinical presentation, diagnosis and surgical treatment of this rare case of spinal hydatid disease is discussed, and all available cases of primary extradural hydatid cyst reported in the literature are presented.

Short report: molecular genetic characterization of an unusually severe case of hydatid disease in Alaska caused by the cervid strain of Echinococcus granulosus

Distinct Echinococcus granulosus life cycle patterns have been described in North America: domestic and sylvatic. Gene sequences of the sylvatic E. granulosus indicate that it represents a separate variant. Case-based data have suggested that the course of sylvatic disease is less severe than that of domestic disease, which led to the recommendation to treat cystic echinococcosis patients in the Arctic by careful medical management rather than by aggressive surgery. We recently reported the first two documented E. granulosus human cases in Alaska, with accompanying severe sequelae. Here we describe the results of molecular genetic analysis of the cyst material of one of the subjects that supported identification of the parasite as the sylvatic (cervid) strain and not the domestic (common sheep strain), which was initially thought to be implicated in these unusually severe Alaskan cases.

Two atypical cases of cystic echinococcosis (Echinococcus granulosus) in Alaska, 1999

Before 1999, clinical experience demonstrated that the sylvatic (or Northern) biotype of Echinococcus granulosus seen in Alaska produced fewer complications and serious sequelae than infection with the pastoral (or European) biotype found in other parts of the world. Two cases of E. granulosus with severe sequelae occurred in Alaska in 1999. The adverse outcomes could have been rare complications that are part of the clinical spectrum of disease caused by sylvatic cystic echinococcus, an indication that the sylvatic biotype, especially when affecting the liver, has potential for severe clinical consequences, or perhaps in one case, infection with a more virulent biotype of E. granulosus contracted during visits to Washington State.

Long-term follow-up and results of thirty pediatric intracranial hydatid cysts: half a century of experience in the Department of Neurosurgery of the School of Medicine at the University of Istanbul (1952-2001)

A series of 30 documented cases of intracranial hydatid cyst out of 33 pediatric and 45 total patients admitted to the Department of Neurosurgery of the School of Medicine at Istanbul University within the years 1952-1996 is presented. The pediatric population consisted of 73% of the series. Twenty patients (66%) are alive and well after a follow-up period of 8-45 years (mean 21.5 years). Six patients (20%) died and 4 (13%) were lost to follow-up. There were 3 early postoperative deaths (10%), 2 being in the pre-CT era. In 4 cases (13%), brain involvement was secondary, and 2 cases (7%) had multiple intracranial hydatid cysts. Age ranged from 4 to 16 years, with a mean of 10.4. There were 5 intraventricular (17%) and 2 (7%) intracranial extradural settlements. No children with posterior fossa hydatid cyst, primary skull hydatidosis or concomitant spinal involvement were detected. One patient (3%) presented with "rhinorrhea" which in fact was a hydatid fluid leak. Preoperative pseudocerebellar syndrome, convulsion and extrapyramidal signs were seen in 6 patients each (20%). Five patients (17%) had permanent visual deficits, 3 being in pre-CT era. Out of 29 patients operated on, hydatid birth with intact cyst removal was achieved in 18 cases (62%), with no other manipulation needed. This rate has increased to 70% in the CT era. Intraoperative accidental rupture occurred in 8 cases (28%), of which 7 were localized frontally or had a frontal involvement (88% of the ruptured cases). Of the patients with intraoperative rupture, 5 are dead (63%) and they were all primary. In contrast, all 3 cases alive with intraoperative rupture are secondary. Three cases were punctured on purpose (10%). Four of the operated patients (14%) required long-term antiepileptic therapy, 3 having no preoperative seizures. Only 1 patient required a shunt (3%). Four cases had recurrence, all with intraoperative cyst rupture (14%). The long-term evaluation of the results yielded an overall mortality rate of 21%. Routine use of CT after the 80s decreased the rate to 14%. With the analysis of 50 years of data, it is strongly concluded that brain involvement in pediatric hydatid disease is a primary process if delayed diagnosis and insufficient treatment of extraneural hydatidosis are prevented.

[Peritoneal hydatidosis: a study of 25 cases in Morocco]

We carried out a retrospective study of 25 cases of peritoneal hydatidosis. The incidence of this disease was 6.9%, the sex ratio of the patients was about 2/1 and the mean age of the patients was 31.8 years. Peritoneal echinococcal disease was most frequently secondary to the rupture or splitting of hydatid cysts in the liver (84% of cases) or, more rarely, in the spleen (4% of cases). The principal symptoms were unusual abdominal pain and abdominal masses. Ultrasound scan is the radiological method of choice for investigation and for assessing the number of hydatid cysts in the abdomen. It was used in 20 cases in this series and led to diagnosis of the disease in 95% of these cases. The sensitivity of CT scan for topographical diagnosis was about 90%. Serological tests were negative for the five remaining patients. Surgical management depends on the location and number of hydatid cysts and on the general state of the patient. Total cyst removal was performed in ten patients, pericystectomy in nine cases and marsupialization in six cases in which the cysts were located in the Douglas cul-de-sac. None of the patients was treated with albendazole. None of the patients died and the morbidity rate was 20%, due mainly to the hepatic location of the cysts. We observed one case of small bowel occlusion due to a missed daughter vesicle, two abscesses of the residual cavity, one case of pleurisy and one case of unexplained febrile syndrome. No recurrence was observed over a follow-up period of five years.

Echinococcus granulosus: DNA extraction from germinal layers allows strain determination in fertile and nonfertile hydatid cysts

A method for the isolation of Echinococcus granulosus DNA from germinal layers of hydatid cysts is described. The method includes a hexadecyltrimethylammonium bromide/chloroform extraction and an adsorption to diatomaceous earth suspension. DNA suitable for polymerase chain reaction was obtained and used for parasite strain determination by mitochondrial cytochrome c oxidase I gene sequencing. Fertile and nonfertile cyst isolates from sheep, cattle, pigs, and humans were characterized. Hitherto, no direct parasite strain characterization has been made on nonfertile hydatid cysts, whereas here we report that nonfertile hydatid cysts were produced by sheep strain (G1 genotype) in sheep, cattle, and humans and by pig strain (G7 genotype) in pigs.

[Sonographic course of systemic echinococcosis in a 10 year old girl (with cardiac, hepatic, renal and muscular involvement)]

PURPOSE

To present the predominantly ultrasonographic (initial and follow-up) imaging in a disease that is rare among the Central European paediatric population--and to evaluate the role of ultrasound for initial staging and follow-up under antihelmintic therapy.

METHOD

The imaging documents as well as the clinical record of a 10-year old Armenian girl with systemic hydatid disease (cystic echinococcosis) were analysed retrospectively.

RESULTS

By means of ultrasound, the complete initial systemic spread of the disease with at least 11 cysts within the liver, 1 cyst in the left kidney, 1 peri-/2 intracardiac cysts, and 1 cyst in the dorsal musculature was detected. Repeated sonographic examinations allowed the estimation of successful medical treatment by the following criteria: size reduction of all cysts with changing internal structures from an initially echo-free to an increasingly homogeneous echodense character; no developing new cysts. In addition, CT and MRI enabled a more complete demonstration of especially the intra- and pericardiac lesions (preoperatively) and the exclusion of further intracranial cysts.

CONCLUSION

In paediatric hydatid disease, ultrasonography yields important information not only with regard to the initial staging, but also to the antihelmintic therapeutic effects and thus helps to determine when to discontinue medical treatment.

Hand-assisted laparoscopic splenectomy for hydatid cyst

Splenic hydatidosis is a rare condition. We performed a hand-assisted laparoscopic splenectomy for a large hydatid cyst localized in the center of the spleen. We discuss the advantages of the "helping hand."

Current trends in the diagnosis and management of cystic hydatid disease of the liver

Cystic hydatid disease caused by Echinococcus granulosus most commonly involves the liver. Recent years have seen many changes in modalities of diagnosis and treatment of cystic disease in the liver. Currently used methods of immunodiagnosis, newer radiological modes of imaging, emerging non-surgical techniques of management and the impact of minimal access surgery in this disease are highlighted in the present review.

Time course of coproantigen excretion in Echinococcus multilocularis infections in foxes and an alternative definitive host, golden hamsters

Coproantigen excretion during experimental infections of Echinococcus multilocularis in foxes and an alternative definitive host, golden hamsters, was evaluated by a sandwich ELISA using a monoclonal antibody. A sigmoidal increase of antigen excretion from the developing parasites was observed in in vitro incubation of the parasites collected on different days during the first 21 days post-infection (DPI). In hamsters, the ELISA O.D. value of faeces became positive at 4 DPI. Thereafter, the O.D. value increased in semi-sigmoidal fashion in the first 42 DPI, probably reflecting the development of the parasites. In foxes, the O.D. value became positive at 6 DPI. However, contrary to that in hamsters, after the initial steep rise, the O.D. value suddenly decreased to 1/2 the level during 15-17 DPI, indicating that a large number of worms might have been expelled. The parasite eggs were detected by the sugar centrifugal-flotation technique (Ito, Yagi & Ishige, 1989) from 29 to 84 DPI but not thereafter to 125 DPI, although mature parasites were detected at 125 DPI. In contrast, positive O.D. values were obtained almost constantly until 125 DPI, indicating that the coproantigen detection assay was more sensitive than the egg detection assay. The detection limit of the coproantigen assay was roughly estimated to be around 100 worms. These observations, along with the fact that the assay was designed to detect a heat-resistant coproantigen in heat-sterilized fecal samples, indicate that the coproantigen detection assay is a safe and useful method, not only for diagnosis in the definitive host of E. multilocularis, but also for monitoring parasite development and change in parasite burden during an experimental infection.

[Repeated strokes as a sign of multiple cerebral hydatid cysts]

A female patient with primary multiple cerebral hydatid cysts is described. Initial deterioration was followed several months later by reversible episodes of right hemiparesis, aphasia and sphincteral incontinence. This clinical picture has not been described in the literature and the etiopathogenic mechanism is uncertain.

Management of problematic intracranial hydatid cysts

The authors report four patients with intracranial hydatic cysts. One patient had a pontine lesion which was punctured and aspirated and the cyst wall removed with a satisfactory outcome. The second patient had multiple cysts which was comparable to meningeomatosis. She had a rapidly deteriorating neurologic condition which proved to be fatal in spite of two consecutive surgical interventions. The third patient had nine lesions although only six were evident on the MRI. All of the cysts were removed, while two cysts ruptured. Multiple paracardial cysts of this patient were surgically removed shortly after the craniotomy. The last patient, again with multiple intracranial hydatid cysts had safe, total removal of all cysts. The first postoperative control CT raised the possibility of recurrence since the CT was highly suggestive of a hydatid cyst. However, this was not confirmed in the follow-up CT examination. Problems and the solutions of management are discussed.

Hydatid cyst of the lumbosacral spine with large pelvic mass

A rare case of hydatid cyst of the lumbosacral spine, causing extensive destruction of the sacrum and a large pelvis mass, is reported; a cutaneous fistula from the pelvic cavity to the posterior lumbar region was also present. The patient was studied by computerized tomography and operated on by combined anterior and posterior approach. The sacral localization of the spinal hydatidosis and its extension into the pelvic cavity are unusual. CT and MR allow a good definition of the bone destruction and the abdominal and pelvic extensions. Radical removal of spinal hydatid cysts may be rarely accomplished, because of the extensive bone invasion, and multiple recurrences, requiring repeating operations, occur in most cases.

Polycystic hydatid disease (Echinococcus vogeli). Clinical, laboratory and morphological findings in nine Brazilian patients

Polycystic hydatid disease occurs in neotropical zones and is caused by Echinococcus vogeli. The paca, a wild rodent, is the intermediate host and the final host is the dog. Seven cases of polycystic hydatid disease autochthonous to the Brazilian Amazon region are described. The disease was polycystic in all cases and diagnosis was based on anatomopathological findings. E. vogeli was identified by the shape and dimensions of the rostellar hooks. The liver was the organ most often involved (6/7), followed by the lungs (2/7) and mesentery (2/7), spleen (1/7) and pancreas (1/7). The main clinical manifestations were abdominal pain, hepatomegaly, jaundice, weight loss, anemia, fever, hemoptysis, palpable abdominal masses and signs of portal hypertension. Hepatic calcifications were detected in four cases. Two cases from the hinterland of the State of São Paulo are also reported. Both had calcified round structures in the liver, highly suggestive of calcified polycystic hydatids. The aim of the present report was to report on this relatively unknown hydatid disorder of Tropical America and to disseminate its clinical, ultrasound and radiological features.

Surgical treatment of hydatid cysts of the heart: report of six cases

Six patients with hydatid cysts of the heart have undergone successful enucleation of the cysts with the aid of cardiopulmonary bypass. Various locations of the cysts and their consequences are discussed in detail. The findings have been confirmed by clinical, radiologic, electrocardiographic, echocardiographic, cardiac catheterization, cardioangiographic, and coronary angiographic studies. All patients are in good condition. Length of follow-up is reported.