Trematoda
Echinostoma
Heterophyidae
Snails
Paramphistomatidae
Systemic infection with Alaria americana (Trematoda). (1/255)
Alaria americana is a trematode, the adult of which is found in mammalian carnivores. The first case of disseminated human infection by the mesocercarial stage of this worm occurred in a 24-year-old man. The infection possibly was acquired by the eating of inadequately cooked frogs, which are intermediate hosts of the worm. The diagnosis was made during life by lung biopsy and confirmed at autopsy. The mesocercariae were present in the stomach wall, lymph nodes, liver, myocardium, pancreas and surrounding adipose tissue, spleen, kidney, lungs, brain and spinal cord. There was no host reaction to the parasites. Granulomas were present in the stomach wall, lymph nodes and liver, but the worms were not identified in them. Hypersensitivity vasculitis and a bleeding diathesis due to disseminated intravascular coagulation and a circulating anticoagulant caused his death 8 days after the onset of his illness. (+info)Natural mass infection by heterophyid metacercariae in aquacultured Japanese eel in Taiwan. (2/255)
A natural mass infection of heterophyid metacercariae in aquacultured Japanese eel Anguilla japonica in Taiwan was observed. Of the 28,000 adult eels in 2 ponds, about 25,000 (90%) showed swollen, cloudy and white eyes. Although morbidity was about 90%, there was no mortality among the affected eels. Histopathological sections showed edema and hemorrhage of the eye. Numerous metacercariae were observed in the muscle tissues around the eyeball, the subcutaneous tissue and even in the cartilage. Of the 6 eels digested with artificial gastric juice, all were found to contain metacercariae in their muscle tissues. The average number of metacercariae recovered from the 6 eels was 1219, with a range of 50 to 3762. These metacercariae, when fed orally to immunodeficient (scid) mice, developed into adult worms which were identified as Procerovum cheni Hsu 1950. The naturally infected eels were transferred to a new pond without snails and their eye lesions were not apparent anymore after 2 wk. In a follow-up investigation, 19 of 20 apparently healthy eels in a nearby aquaculture farm were found to harbour metacercariae in their muscles. However, the number of the metacercariae ranged from 1 to 14, with an average of 4.21. This is the first report of heterophyid metacercariae causing mass morbidity in aquacultured eels. (+info)Survey of Fascioloides magna in farmed wapiti in Alberta. (3/255)
The formalin-ethyl acetate sedimentation procedure was used to detect ova of the giant liver fluke, Fascioloides magna, in feces of farmed wapiti in Alberta. Twenty (3.2%) of the 629 fecal samples examined contained ova of F. magna. Thirteen (33.3%) of the 39 farms surveyed had wapiti positive for F. magna. The presence of F. magna in farmed wapiti north of the North Saskatchewan River is confirmed, and 3 areas where the infection has become endemic are identified. (+info)Morphological clues from multilegged frogs: are retinoids to blame? (4/255)
Morphological analysis was performed on multilegged deformed frogs representing five species from 12 different localities in California, Oregon, Arizona, and New York. The pattern of duplicated limbs was consistent with mechanical perturbation by trematode infestation but not with the effects of retinoids. (+info)The effect of trematode infection on amphibian limb development and survivorship. (5/255)
The causes of amphibian deformities and their role in widespread amphibian declines remain conjectural. Severe limb abnormalities were induced at high frequencies in Pacific treefrogs (Hyla regilla) exposed to cercariae of a trematode parasite (Ribeiroia sp.). The abnormalities closely matched those observed at field sites, and an increase in parasite density caused an increase in abnormality frequency and a decline in tadpole survivorship. These findings call for further investigation of parasite infection as a cause of amphibian deformities in other sites and species. (+info)Infections by helminth parasites in "puyenes", Galaxias maculatus (Galaxiidae, Salmoniformes), from Southern Argentina with special reference to Tylodelphys barilochensis (Digenea, Platyhelminthes). (6/255)
The occurrence of Tylodelphys barilochensis, Acanthostomoides apophalliformis, Contracaecum sp. and Camallanus corderoi infecting Galaxias maculatus ("puyenes") was quantified for the first time in Lake Nahuel Huapi, southern Argentina. T. barilochensis was recorded in this lake for the first time. The role of G. maculatus population in transmission of parasites to the salmonids is more important for Contracaecum sp. (prevalence 14-34%) and A. apophalliformis (prevalence 30-54%) than for C. corderoi (prevalence 6-8%). The absence of Diphyllobothrium spp. in samples shows that the G. maculatus population does not play any role in the life cycles of these important zoonotic parasites. The sex of the host had no effect on T. barilochensis abundance. Statistical differences in T. barilochensis abundance between "puyenes" of the same size class between sampling stations and positive correlation between prevalence of infected snails and T. barilochensis abundance in fish suggest that different stocks have been sampled. Factors influencing T. barilochensis abundance are discussed. (+info)A Monte Carlo simulation model for assessing the risk of introduction of Gyrodactylus salaris to the Tana river, Norway. (7/255)
The Tana river in northern Norway, the most productive salmon river in Europe, is free of Gyrodactylus salaris. Currently there is one salmon farm in operation on the Tana fjord. Because of the strong association between stocking of rivers with salmon and infestations with G. salaris there is national and international concern that the existing farm might lead to the introduction of the parasite to the Tana river. In response to these concerns a quantitative analysis of the risk of introduction of G. salaris to the Tana river was undertaken. A scenario tree, the Monte Carlo simulation model and results of the simulations including sensitivity analyses are presented and discussed. Results show that the probability of introduction of G. salaris to the Tana river via transfer of smolt to the existing salmon farm is extremely low primarily due to the low probability that the transferred smolt become infested. The total risk was very sensitive to changes in the salinity of the water at the sea site. (+info)An incidental case of human Heterophyes nocens infection diagnosed by sectional morphology in a biopsy specimen of the small intestine. (8/255)
A case of human infection with Heterophyes nocens (Heterophyidae) was incidentally found in a biopsy specimen of the Meckel's diverticulum at the upper part of the small intestine. The patient was a 58-year-old man living in a rural area of Talsonggun, Kyongsangbuk-do. He had gastrointestinal symptoms such as epigastric pain, indigestion, and abdominal discomfort for 3 months, and severe diarrhea, abdominal pain, and vomiting for about 1 month before hospitalization. Endoscopy of the upper part of the small intestine revealed a Meckel's diverticulum, and it was excised and histopathologically examined. Three adult flukes were incidentally found sectioned in the mucosa, and they were identified as H. nocens. The patient had a history of eating raw mullets at a fish market in Pusan 6 months ago, and the mullets were presumed to be the source of infection. This case brings a considerable interest in that specific diagnosis of heterophyid infections could be done by sectional morphology of the worms. (+info)Trematode infections, also known as trematodiasis or fluke infections, are parasitic diseases caused by various species of flatworms called trematodes. These parasites have an indirect life cycle involving one or two intermediate hosts (such as snails or fish) and a definitive host (usually a mammal or bird).
Humans can become accidentally infected when they consume raw or undercooked aquatic plants, animals, or contaminated water that contains the larval stages of these parasites. The most common trematode infections affecting humans include:
1. Schistosomiasis (also known as bilharzia): Caused by several species of blood flukes (Schistosoma spp.). Adult worms live in the blood vessels, and their eggs can cause inflammation and damage to various organs, such as the liver, intestines, bladder, or lungs.
2. Liver flukes: Fasciola hepatica and Fasciola gigantica are common liver fluke species that infect humans through contaminated watercress or other aquatic plants. These parasites can cause liver damage, abdominal pain, diarrhea, and eosinophilia (elevated eosinophil count in the blood).
3. Lung flukes: Paragonimus spp. are lung fluke species that infect humans through consumption of raw or undercooked crustaceans. These parasites can cause coughing, chest pain, and bloody sputum.
4. Intestinal flukes: Various species of intestinal flukes (e.g., Haplorchis spp., Metagonimus yokogawai) infect humans through consumption of raw or undercooked fish. These parasites can cause abdominal pain, diarrhea, and eosinophilia.
5. Eye fluke: The oriental eye fluke (Drepanotrema spp.) can infect the human eye through contaminated water. It can cause eye inflammation, corneal ulcers, and vision loss.
Prevention measures include avoiding consumption of raw or undercooked aquatic plants, animals, and their products; practicing good hygiene; and treating drinking water to kill parasites. Treatment typically involves administering anthelmintic drugs such as praziquantel, albendazole, or mebendazole, depending on the specific fluke species involved.
Trematoda is a class of parasitic flatworms, also known as flukes. They have a complex life cycle involving one or more intermediate hosts and a definitive host. Adult trematodes are typically leaf-shaped and range in size from a few millimeters to several centimeters.
They have a characteristic oral sucker surrounding the mouth and a ventral sucker, which they use for locomotion and attachment to their host's tissues. Trematodes infect various organs of their hosts, including the liver, lungs, blood vessels, and intestines, causing a range of diseases in humans and animals.
Examples of human-infecting trematodes include Schistosoma spp., which cause schistosomiasis (also known as bilharzia), and Fasciola hepatica, which causes fascioliasis (liver fluke disease). Trematode infections are typically treated with antiparasitic drugs.
Echinostoma is a genus of parasitic flatworms, specifically trematodes, that are known to infect various species of birds and mammals, including humans. These parasites have a complex life cycle involving multiple hosts, typically snails as the intermediate host and aquatic animals (such as fish or amphibians) as the secondary host. Humans can become infected by consuming raw or undercooked infected secondary hosts.
Echinostoma species are characterized by having a distinctive oral sucker surrounded by a collar of spines, which gives them their name (echinos means "spiny" in Greek). The adult worms live in the intestines of their definitive host and can cause symptoms such as abdominal pain, diarrhea, nausea, and vomiting. In severe cases, infection with Echinostoma species can lead to weight loss, malnutrition, and other complications.
It's worth noting that while human infections with Echinostoma species are relatively rare in developed countries, they can be more common in areas where raw or undercooked aquatic animals are consumed as part of traditional diets. Proper cooking and hygiene practices can help prevent infection with these parasites.
Heterophyidae is a family of small intestinal fluke parasites, which are trematodes. These parasites have a complex life cycle involving one or two intermediate hosts, usually snails and fish, before infecting the definitive host - a mammal, bird, or reptile. The most common species that infect humans include Heterophyes heterophyes, Metagonimus yokogawai, and Haplorchis taichui.
Human infection typically occurs through the consumption of raw or undercooked fish containing metacercariae (the infective stage). Once ingested, the metacercariae excyst in the small intestine, where they mature into adults and attach to the intestinal wall. The adult flukes are relatively small, usually less than 2 mm in length, and feed on blood and tissue fluids from the host's intestinal mucosa.
Light infections may be asymptomatic or cause mild gastrointestinal symptoms such as abdominal pain, diarrhea, nausea, or vomiting. Heavy infections can lead to more severe complications, including intestinal obstruction, malabsorption, and anemia due to blood loss. In some cases, the infection may disseminate to other organs, causing extraintestinal manifestations such as hepatomegaly (enlarged liver), splenomegaly (enlarged spleen), or pulmonary symptoms if larvae migrate to the lungs.
Prevention of heterophyidiasis involves avoiding the consumption of raw or undercooked fish, especially in endemic areas. Proper cooking and freezing techniques can effectively kill metacercariae and prevent infection. Infected individuals should receive appropriate medical treatment with anti-parasitic drugs such as praziquantel to eliminate the parasites and alleviate symptoms.
I'm sorry for any confusion, but the term "snails" is not a medical term. It is a common name used to refer to a large group of land and sea-dwelling mollusks that have coiled shells and move slowly by means of a muscular foot. If you have any questions about medical terminology or health-related topics, I'd be happy to help! Just let me know what you're looking for.
Paramphistomatidae is a family of parasitic flatworms, also known as trematodes or flukes. These parasites primarily infect the digestive system of ruminant animals such as cattle, sheep, and goats, but can also be found in other mammals, birds, and even humans. The life cycle of Paramphistomatidae involves several intermediate hosts, typically snails, before reaching their definitive host. The adult worms reside in the upper digestive tract, causing diseases known as paramphistomiasis, which can result in symptoms such as diarrhea, weight loss, and anemia.