PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Echinostomiasis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources

Echinostomiasis: a common but forgotten food-borne disease.

Human echinostomiasis, endemic to southeast Asia and the Far East, is a food-borne, intestinal, zoonotic parasitosis attributed to at least 16 species of digenean trematodes transmitted by snails. Two separate life cycles of echinostomes, human and sylvatic, efficiently operate in endemic areas. Clinical symptoms of echinostomiasis include abdominal pain, violent watery diarrhea, and anorexia. The disease occurs focally and transmission is linked to fresh or brackish water habitats. Infections are associated with common sociocultural practices of eating raw or insufficiently cooked mollusks, fish, crustaceans, and amphibians, promiscuous defecation, and the use of night soil (human excrement collected from latrines) for fertilization of fish ponds. The prevalence of infection ranges from 44% in the Philippines to 5% in mainland China, and from 50% in northern Thailand to 9% in Korea. Although the patterns of other food-borne trematodiases have changed in Asia following changes in habits, cultural practices, health education, industrialization, and environmental alteration, human echinostomiasis remains a health problem. The disease is most prevalent in remote rural places among low-wage earners and in women of child bearing age. Echinostomiasis is aggravated by socioeconomic factors such as poverty, malnutrition, an explosively growing free-food market, a lack of supervised food inspection, poor or insufficient sanitation, other helminthiases, and declining economic conditions. Furthermore, World Health Organization control programs implemented for other food-borne helminthiases and sustained in endemic areas are not fully successful for echinostomiasis because these parasites display extremely broad specificity for the second intermediate host and are capable of completing the life cycle without involvement of the human host.

Amphibians↗

A case of echinostomiasis with ulcerative lesions in the duodenum.

Echinostomiasis is an endemic intestinal trematodiasis of humans in Korea. We observed a human case of Echinostoma hortense infection who had ulcerations on the duodenal mucosa. A 55-year old man living in Hamyang-gun, Kyongnam, complained of epigastric pain with hematemesis in April 1994. Endoscopy revealed lesions of early gastric cancer and duodenal ulcerations. A penetrating parasite into the duodenal mucosa was picked out, and identified as E. hortense. As the patient was treated with praziquantel 10 mg/kg single dose, 3 more E. hortense and 7 Metagonimus worms were recovered. This case demonstrates that echinostomiasis causes gross ulcerations in the duodenum.

Duodenal Ulcer↗

Echinostomiasis--a snail-borne intestinal trematode zoonosis.

Numerous echinostome trematodes are found in the intestines of birds and mammals throughout the world, and echinostomiasis in humans has been attributed to approximately 16 different species. In humans it is usually regarded as a rare intestinal parasite of little clinical importance except in heavy infections. Diagnosis of echinostomiasis is made by identification of eggs during fecal examination; however, speciation of echinostomes requires morphological study of adult worms following anthelminthic treatment. The complex life cycles of echinostomes are all linked to freshwater habitats. A mammalian or avian definitive host, one or two molluscan hosts, and one or two freshwater stages are usually required to complete the life cycle. In addition, amphibians and fish have been implicated in the transmission of some species. Prevention of human cases is dependent on eating habits, since raw or insufficiently cooked molluses, and to a lesser extent fish and amphibians, are sources of infection for humans. Human cases have been effectively, albeit accidentally, controlled by the introduction of fish which prey on the larval stages of the essential molluscan hosts.

Animals↗

[Studies on the zoonoses in Hokkaido, Japan. 6. Experimental human echinostomiasis].

Etiological analysis and parasitological examinations of human echinostomiasis were investigated. The four volunteers (case A, B, C and D) were orally administrated metacercariae harvested from the fresh water snails (Lymnaea japonica) experimentally infected with Echinostoma hortense eggs. Numbers of metacercariae administrated were 20 for cases A and B, 30 for case C and 50 for case D. Prepatent periods of four cases were 14 days (case D) and 17 days (cases A,B and C) after administrations. Patent periods of egg output were 18 days (case A), 32 days (case C), 207 days (case B) and 209 days (case D). The latter of two cases (B and D) showed the longest period of egg output in human echinostomiasis. Case A revealed the symptoms of violent watery diarrhoea and abdominal pain from 3rd to 4th weeks after administration, but others were asymptomatic. Maximal eosinophilia (22-35%) in peripheral blood of the three cases (cases A, C and D) was recognized 4 weeks after administration and the values decreased gradually thereafter. Case B did not show eosinophilia during the experimental period. Total serum IgE value measured by RIST method did not rise in all cases.

Adult↗

Clinical and pathological effects of Echinostoma revolutum (Digenea: Echinostomatidae) in the golden hamster, Mesocricetus auratus.

Laboratory hamsters (Mesocricetus auratus) were infected with Echinostoma revolutum (Trematoda). Hamsters developed marked and sometimes fatal echinostomiasis. Clinical signs included progressive unthriftiness, watery diarrhoea and weight loss. Packed cell volume, haemoglobin and red blood cell counts increased in those animals with severe diarrhoea. No increase in eosinophils was noted in peripheral blood smears. Examination of tissues of infected animals showed wide individual variations related to the intensity of infection. The histopathological responses of hamsters to the parasite showed erosion of intestinal villi with lymphocytic infiltration being the primary response. Periportal lymphocytic infiltration and focal hepatic necrosis were observed in livers from some infected animals. The findings of this study are discussed in terms of variations in pathogenicity of E. revolutum and as a model for the study of echinostomiasis.

Animals↗

[Studies on Echinostoma spp. in the Chungju Reservoir and upper streams of the Namhan River].

The present study was performed to know the epidemiological status of echinostomiasis in the Chungju Reservoir and upper streams of Namhan River, together with an experimental study on the life history of Echinostoma hortense. The stool specimens of 169 inhabitants and 473 junior high school students from 5 different villages revealed 3 (0.5%) echinostomatid egg positive cases. E. hortense adult worms were recovered from one patient after a treatment and purgation. For the other two patients, it was presumed that one had E. hortense and another E. cinetorchis infection, based on the morphology of eggs. Five kinds of freshwater snails (168 Radix auricularia coreana, 534 Physa acuta, 144 Hippeutis cantori, 56 Cipangopaludina chinensis malleata and 125 Semisulcospira nodifila globus) examined for the cercariae of echinostomes showed negative results. Ten kinds of freshwater fishes examined for E. hortense metacercariae revealed positive rates as Misgurnus anguillicaudatus 40.5%, Odontobutis obscura interrupta 20.3%, Moroco oxycephalus 3.9%, and Coreoperca kawamebari 2.0%. In the experimental study, the metacercariae of E. hortense were infected to rats, eggs were collected from adult worms and cultivated, and miracidia were obtained. The miracidia were artificially infected to freshwater snails (R. auricularia), and cercarial shedding was studied. It was revealed that, when the snails were kept at a low temperature (24 degrees C), only 523 cercariae (on average) were produced during 24 hrs, while they were at a high temperature (30 degrees C), as many as 9,990 cercariae (on average) were shed during the same time. The experimental infection of E. hortense cercariae to freshwater fishes was successful in O. obscura interrupta 52.0%, M. anguillicaudatus 30.3%, C. kawamebari 27.0%, Cobitis lutheri 15.0%, M. oxycephalus 7.3%, Pseudogobio esocinus 4.3%, Squalidus coreanus 2.0%, Zacco platypus 1.3%, and Pungtungia herzi 1.3%. However, infection was not successful to snails, C. chinensis. It has been proved that the Chungju Reservoir and upper streams of Namhan river are endemic areas of echinostomiasis, especially of E. hortense, and snails such as R. auricularia coreana and fishes such as O. obscura interrupta, M. anguillicaudatus, and others are taking the role of first and second intermediate hosts, respectively.

Animals↗

A human infection of Echinostoma hortense in duodenal bulb diagnosed by endoscopy.

As gastroduodenoscopy performed more frequently, case reports of human echinostomiasis are increasing in Korea. A Korean woman presented at a local clinic with complaints of abdominal pain and discomfort that had persisted for 2 weeks. Under gastroduodenoscopy, two motile flukes were found attached on the duodenal bulb, and retrieved with endoscopic forceps. She had history of eating raw frog meat. The two flukes were identified as Echinostoma hortense by egg morphology, 27 collar spines with 4 end-group spines, and surface ultrastructural characters. This report may prove frogs to be a source of human echinostome infections.

Animals↗

Eating habits associated with Echinostoma malayanum infections in the Philippines.

A survey of 61 residents belonging to 12 pre-selected families (having at least one member positive for echinostomiasis malayanum) from Barangay Malibago, Echague, Isabela (northern Luzon) suggested that infections with Echinostoma malayanum follow a "familial trend". The parasite is endemic because the raw ingestion of Lymnaea (Bullastra) cumingiana, the second intermediate host in the Philippines, is a learned habit passed down from one generation to the next. A questionnaire on eating habits revealed that Lymnaea (Bullastra) cumingiana or "birabid" was usually prepared raw or half-cooked after treatment with salt or "bagoong" (salted fish paste). It was abundant in rice fields during the wet months of the year, thus implying a seasonal infection pattern since eating frequency was affected by availability. Those who ate this snail reported a long duration of indulgence with this habit. In contrast, Pila luzonica or "kuhol", the second intermediate host of E. ilocanum, is subjected to similar eating practices but is rarely ingested raw or "half-cooked". Other than snails, shrimps, fish (Tilapia sp.) and meat are also eaten raw. This suggests that the local population is potentially susceptible to other food-borne helminthiases. Extensive use of mass media and public health education is necessary to awaken the awareness of the people to the potential hazards associated with their traditional eating habits.

Animals↗