Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Echinococcus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources
PubMed2005

Modified sugar centrifugal flotation technique for recovering Echinococcus multilocularis eggs from soil.

Among soil-transmitted parasitic diseases, alveolar hydatidosis due to the ingestion of Echinococcus multilocularis eggs is becoming a serious problem in Hokkaido, the northern most island of Japan. Dissemination of the infection far from the endemic areas can occur if motor vehicles transmit soil contaminated with eggs. No appropriate and validated method for recovering the taeniid eggs from soil is available. A modified sugar centrifugal flotation technique, using a sucrose solution of specific gravity 1.27 and 0.05% Tween-80, was evaluated as a method to successfully recover eggs from soil. Contamination levels as low as 10 eggs per gram could be detected. This method may be useful to determine the prevalence of E. multilocularis, its transmission, and the potential for by monitoring soil contamination with eggs.

Animals↗
PubMed1992

Parasitological and serological studies on the prevalence of Echinococcus multilocularis Leuckart, 1863 in red foxes (Vulpes vulpes Linnaeus, 1758) in Switzerland.

In the Canton of Zurich in Switzerland, 1,252 red foxes (Vulpes vulpes) were examined during 1990-1991 for intestinal stages of Echinococcus multilocularis using the mucosal smear technique. Special safety precautions were employed during examination. An average of 35% (432 foxes) were infected, mostly with low to medium numbers of gravid worms producing thick-shelled eggs. In the eleven districts of the Canton, prevalence rates varied between 13% and 57%. An average of 29% of the foxes had antibodies in serum or body fluid against a highly species-specific antigen of E. multilocularis (Em2-antigen). The fact that foxes with intestinal E. multilocularis infection have been found in all parts of the Canton of Zurich indicates a relatively high potential infection risk for humans, but apparently the risk is reduced by certain extrinsic or intrinsic factors which have yet to be determined.

Age Factors↗
PubMed2003

Echinococcus multilocularis: an emerging pathogen in Hungary and Central Eastern Europe?

Echinococcus multilocularis, the causative agent of human alveolar echinococcosis, is reported for the first time in Red Foxes (Vulpes vulpes) in Hungary. This parasite may be spreading eastward because the population of foxes has increased as a consequence of human interventions, and this spread may result in the emergence of alveolar echinococcosis in Central Eastern Europe.

Animals↗
PubMed2006

Pasture types and Echinococcus multilocularis, Tibetan communities.

Our study showed that open pastures had more small mammal burrows than fenced pastures in Tibetan pastoralist communities in 2003. This characteristic was linked to a higher prevalence of Echinococcus multilocularis in dogs and indicates that pasture type may affect E. multilocularis transmission.

Animals↗
PubMed1989

Cross-reacting and specific antigenic components in cystic fluid from metacestodes of Echinococcus granulosus and Taenia solium.

Sera from confirmed patients of 5 hydatidosis, 67 neurocysticercosis and 89 other parasitic diseases were tested for specific antibody (IgG) levels by ELISA to cystic fluid antigens from metacestodes of Echinococcus granulosus (HF) and Taenia solium (CF). All hydatidosis sera reacted positively to both HF and CF while neurocysticercosis sera did in 49.3% to HF and 85.1% to CF. The frequencies of cross-reactions were lower in other parasitic diseases to both antigens. By SDS-PAGE, protein bands of 64, 35, 22 and 7 kilodaltons (kDa) were found common in HF and CF. SDS-PAGE/immunoblot exhibited that hydatidosis sera reacted crossly to CF at 135, 110, 100, 86, 64, 45, 39, 35 and 24 kDa bands while neurocysticercosis sera did to HF at 135, 100, 86, 64, 52, 39, 35, 29 and 24 kDa bands. These results indicated that protein bands of 135, 100, 86, 64, 39, 35 and 24 kDa were major common components in HF and CF. Protein bands of 7 kDa in HF and 15, 10 and 7 kDa in CF did not react crossly and were specific components in respective antigens.

Animals↗
PubMed2002

Echinococcus granulosus protoscolex formation in natural infections.

Echinococcus granulosus is a parasitic platyhelminth that is responsible for cystic hydatid disease. From the inner, germinal layer of hydatid cysts protoscoleces are generated, which are are the infective forms to the dog. Systematic studies on the cell biology of E. granulosus protoscolex formation in natural infections are scarce and incomplete. In the present report we describe seven steps in the development of protoscoleces. Cellular buds formed by a clustering of cells emerge from the germinal layer of hydatid cysts. The buds elongate and the cells at their bases seem to diminish in number. Very early on a furrow appears in the elongated buds, delimiting anterior (scolex) and caudal (body) regions. Hooks are the first fully-differentiated structures formed at the apical region of the nascent scolex. In a more advanced stage, the scolex shows circular projections and depressions that develop into suckers. A cone can later be seen at the center of the hooks, the body is expanded and a structured neck is evident between the scolex and the body. During protoscolex development this parasitic form remains attached to the germinative layer through a stalk. When fully differentiated, the stalk is cut off and the infective protoscolex is now free in the hydatid fluid.

Animals↗
PubMed1978

Discrimination of the larval stages of Echinococcus oligarthrus (Diesing, 1863) and E. vogeli Rausch and Bernstein, 1972 (Cestoda: Taeniidae).

Rostellar hooks of protoscolices from known larval stages of Echinococcus oligarthrus (Diesing, 1863) and E. vogeli Rausch and Bernstein, 1972 were compared to determine whether morphologic differences could be defined. The large and small hooks, respectively, of the two species were found to differ significantly in length (P = less than 0.0001) as well as in relative proportions. Host-related variation in lengths of hooks was not observed. Dimensions of the rostellar hooks were found to provide means for the discrimination of the larval stages of E. oligarthrus and E. vogeli, of which the latter is the cause of polycystic hydatid disease in man in South and Central America. The defined criteria were used in the identification of larvae from wild rodents and man.

Echinococcus↗
PubMed1979

Echinococcus vogeli in man, with a review of polycystic hydatid disease in Colombia and neighboring countries.

Three cases of polycystic hydatid disease (PHD) from Colombia are reported and 11 others from the region are reviewed. When cysts from two patients were fed to a dog and an ocelot about 250 mature and gravid specimens of Echinococcus vogeli and two poorly developed strobilae, respectively, were recovered. These human cases constitute the first record of the larval stage of E. vogeli, previously known only from the strobilar stage in the type host, the bush dog (Speothos venaticus). Based on the morphological characteristics of the protoscolex rostellar hooks from other PHD cases (6 Colombian, 1 Ecuadorian, and 1 Panamanian), it was concluded that all were also due to E. vogeli, rather than to E. oligarthrus as had been previously suggested. Although E. oligarthrus is or may be present in the same areas, so far no human infection due to this parasite has been confirmed. Of the 14 cases reported, 13 were pathologically proven to be PHD. Clinically, eight had an undiagnosed tumor-like mass in or near the liver, one had a subcutaneous mass in the anterior sixth intercostal space, and in two the cysts were in the chest. Two were autopsy findings. In contrast to E. multilocularis, the cysts produced by E. vogeli were found to be relatively large and filled with fluid; brood capsules and protoscolices were numerous. Focal necrosis was commonly observed but large necrotic cavities were not seen. The main natural intermediate host is the paca (Cuniculus paca); man probably obtains the infection by contamination from feces of infected hunting dogs.

Adolescent↗
PubMed1981

Characteristics of the larval Echinococcus vogeli Rausch and Bernstein, 1972 in the natural intermediate host, the paca, Cuniculus paca L. (Rodentia: Dasyproctidae).

In Colombia, the natural intermediate host of Echinococcus vogeli Rausch and Bernstein, 1972 is the paca, Cuniculus paca L. (Rodentia: Dasyproctidae). The larval cestode develops in the liver of the host, where it usually is situated superficially, partly exposed beneath Glisson's capsule. The infective larva consists of a subspherical to asymmetrical, fluid-filled vesicle, up to 30 mm in diameter, enclosed by a thick laminated membrane. It typically contains numerous chambers, often interconnected, produced by endogenous proliferation of germinal and laminated tissue, within which brood capsules arise in an irregular pattern from the germinal layer. Invasive growth by means of exogenous proliferation, typical of infections in man, was not observed in the natural intermediate host. The development of the larval cestode is described on the basis of material from pacas, supplemented by observations on early-stage lesions in experimentally infected nutrias, Myocastor coypus (Molina) (Rodentia: Capromyidae). The tissue response is characterized for early-stage, mature (infective), and degenerating larvae in the comparatively long-lived intermediate host. In addition to previously reported differences in size and form of rostellar hooks, other morphologic characteristics are defined by which the larval stage of E. vogeli is distinguished from that of E. oligarthrus (Diesing, 1863). Pathogenesis by the larval E. vogeli in man, like that by the larval E. multilocularis Leuckart, 1863, is the consequence of atypical proliferation of vesicles attributable to parasite-host incompatibility.

Animals↗
PubMed1983

Serologic tests for diagnosis and post-treatment evaluation of patients with alveolar hydatid disease (Echinococcus multilocularis).

The indirect hemagglutination (IHA) and immunoelectrophoresis (IEP) tests were used for diagnosis and follow-up evaluation of 17 patients with alveolar hydatid disease caused by Echinococcus multilocularis. Follow-up periods ranged from 2 to 22 years. At the time of diagnosis 16 (94%) patients' sera gave IHA titers greater than or equal to 1:128. Serum specimens from 13 patients were examined by IEP; nine (69%) revealed the arc 5, and three of the four arc 5-negative sera revealed one or more non-characterized bands. Titers declined markedly during the first year following radical surgical resection of the larval lesions; in three cases clinical evidence of recurrence was preceded by rising serologic titers. Antibody has persisted at high levels in non-resected patients treated continuously with high doses of mebendazole.

Adolescent↗
PubMed1983

An active intermediate host role for man in the life cycle of Echinococcus granulosus in Turkana, Kenya.

Hydatid material removed at operation from 97 Turkana was compared for fertility and viability with hydatid material removed from camels, cattle, sheep, and goats. The results showed that the human material was extremely fertile and viable, as was material from the camels, goats, and sheep. Cattle cysts were invariably sterile, and the protoscoleces, when present, were comparatively less viable. The high incidence and fertility of hydatid cysts in the Turkana, together with the lack of burial customs thus allowing dogs to have ready access to infected human corpses, means that the Turkana are potential biological participants in the cyclic transmission of Echinococcus granulosus in this region. This is a unique situation, for elsewhere in the world man is regarded as an accidental host who plays no role in the parasite's life cycle.

Adolescent↗
PubMed1986

Specific antibody responses in dogs experimentally infected with Echinococcus granulosus.

Six dogs reared helminth-free were divided into 2 groups. Four dogs were infected per os with 200,000 protoscoleces each of Echinococcus granulosus and 2 were kept as uninfected controls. All the dogs were kept together until 32 days after infection, when 1 infected dog was killed, its intestine removed and the contents examined to confirm that the infection with E. granulosus had been successful. The remaining 3 infected dogs were transferred to high security housing and their feces inspected daily to establish the time infections became patent. The infected and control dogs were bled every 5 days for 75 days from the time of infection and the sera were stored at -70 degrees C. Sera were tested by the enzyme-linked immunosorbent assay (ELISA) for antibodies to E. granulosus scolex excretory/secretory (ES) antigen, protoscolex antigen and oncosphere antigen. Antibodies to scolex ES antigen and protoscolex antigen were detected in the sera of infected dogs within 2 weeks of infection. Antibody titers rose rapidly and remained at a high level until the dogs were killed 75 days after infection. Antibodies in these sera did not cross react with antigens prepared from Taenia ovis, T. hydatigena, T. pisiformis, Ancylostoma caninum, Trichuris vulpis and Toxocara canis.

Animals↗
PubMed1986

Serum antibody response following parenteral immunization with hydatid cyst fluid in sheep infected with Echinococcus granulosus.

Production of specific serum antibodies following immunization with hydatid cyst fluid antigens was investigated in sheep with Echinococcus granulosus infection and in noninfected controls. Six of 10 infected animals responded to intramuscular injection of antigen by rapid production of antibodies detected in indirect hemagglutination assays. Similar responses did not occur in any of 10 noninfected controls. It is suggested that differences in the rate of response to immunization with cyst fluid antigens between groups of sheep could be exploited in serodiagnosis of E. granulosus infection in sheep. The results also suggest that low levels of antibody found in the serum of sheep infected with E. granulosus are not the result of immunosuppression or immunological tolerance, but are due to sequestration of antigen from the immune system of the host.

Animals↗
PubMed1987

Spontaneous death of Echinococcus multilocularis: cases diagnosed serologically (by Em2 ELISA) and clinical significance.

Nine cases of asymptomatic alveolar hydatid disease (AHD) of the liver were diagnosed in 1985 among Eskimos from the endemic region of western Alaska. The patients were identified by screening with the enzyme-linked immunosorbent assay, using purified Echinococcus multilocularis antigen (Em2 ELISA). Five patients, and one diagnosed earlier (1979), were found to have lesions in which the larval E. multilocularis had died spontaneously at an early stage of infection. Viability was assessed histologically; by the avidin-biotin immunohistochemical method; and in vivo through intraperitoneal inoculation of membranes of the larval cestode into red-backed voles, Clethrionomys rutilus. The results were in agreement with the clinical impression, based on findings by computerized tomography and ultrasound scanning, and on the macroscopic appearance of the lesions, that the cestode was dead. Spontaneous death of E. multilocularis in humans has not been previously reported. The findings show that the Em2 ELISA may be positive in patients having lesions of AHD in which the etiologic agent is no longer viable.

Aged↗
PubMed1991

Specific cellular and humoral immune responses in patients with different long-term courses of alveolar echinococcosis (infection with Echinococcus multilocularis).

Alveolar echinococcosis is a serious and often fatal disease of humans that in most cases can be efficiently cured only by complete surgical resection of the Echinococcus multilocularis lesion. In a few patients, however, a spontaneous cure of the disease has been observed by demonstrating the presence of lesions with dead metacestodes. The present study shows a comparative analysis of the cellular (lymphoproliferative assay) and humoral (antibody activity in an Em2 enzyme-linked immunosorbent assay [ELISA] and immunoblotting) immune response in 1) patients who were cured by a radical surgical resection of the E. multilocularis parasite lesion, 2) patients who had a partial surgical resection of the parasite lesion, 3) patients who had a non-resectable alveolar echinococcosis, and 4) patients who were shown to be spontaneously cured and had lesions with dead parasites. The in vitro lymphoproliferative response to E. multilocularis antigen stimulation was very high in cured patients who had radical surgery or in patients with lesions containing dead parasites, but it was significantly lower in patients who had partial surgical or no resection. Antibody concentrations in the Em2-ELISA were high in patients who had incomplete or no surgery, and low or negative in cured patients who had radical surgery or in patients with lesions containing dead parasites. Immunoblot analysis of patient sera revealed a consistent antibody banding pattern among cured patients with radical surgery and patients with incomplete or no surgery, whereas cured patients with lesions containing dead parasites showed a very faint antibody pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Molecular examination of the sympatry and distribution of sheep and camel strains of Echinococcus granulosus in Kenya.

Previous studies have shown that camel and sheep strains of the cystic hydatid parasite Echinococcus granulosus occur in Kenya. We examined 208 larval isolates and 40 worm samples of E. granulosus from various hosts in Kenya using restriction fragment length polymorphism analysis of a segment of ribosomal DNA amplified by the polymerase chain reaction. This was in an effort to determine whether additional strains of E. granulosus occur in Kenya, to examine the level of genetic heterogeneity within the sheep/dog and camel/dog strains previously identified, and to map out their intermediate host range and geographic distribution in Kenya. We confirmed the existence of the two strains in Kenya and showed that the distribution of the camel strain appears restricted to the Turkana region, where camels are kept as livestock. The intermediate host range for both strains seems to be similar except that humans appear refractory to infection with the camel strain. We have also shown that although the life-cycle patterns of the two strains overlap both geographically and in intermediate and definitive hosts, the strains maintain their homogeneous genetic identity.

Abattoirs↗
PubMed1993

Echinococcus granulosus:isoprinosine treatment of the metacestode stage.

The efficacy of short- and long-term treatments with Isoprinosine, an immunomodulatory compound, was studied in Echinococcus granulosus cysts developed in NMRI mice intraperitoneally infected with sheep pulmonary cysts. After treatment, a reduction in the size and number of cysts with macroscopic modifications was observed. The structural alterations included damage or destruction of the protoscoleces and partial destruction of the cyst wall, which predominated at the inner germinal layer level. The efficacy of this drug was evaluated after long-term and short-term treatment. Short-term treatment with a dose of 1 g/kg/day gave better results, with a loss of infectivity of the larval tissue. The well-tolerated long-term treatment with a dose of 2 g/kg/day showed the absence of toxicity of this compound. The survival time of treated animals was greater than that of untreated controls.

Animals↗