No special status Other Comments In countries that Fasciola gigantica is present, the prevalence of infected animals is extremely high. Sobhon, et al. Glossary living in sub-Saharan Africa south of 30 degrees north and Madagascar. Palearctic living in the northern part of the Old World.
|Published (Last):||25 February 2018|
|PDF File Size:||17.67 Mb|
|ePub File Size:||10.82 Mb|
|Price:||Free* [*Free Regsitration Required]|
In addition to humans it infects cows and sheep. It is known as the common liver fluke and causes a disease called fascioliasis.
The life cycle of Fasciola hepatica starts when a female lays eggs in the liver of an infected human. Immature eggs are discharged in the biliary ducts and taken out in the feces. If landed in water, the eggs become embryonated and develop larvae called miracidia. A miracidium invades an aquatic snail and develops into cercaria, a larva that is capable of swimming with its large tail.
The cercaria exits and finds aquatic vegetation where it forms a cyst called metacercaria. A human eats the raw freshwater plant containing the cyst. The metacercaria excysts in the first part of the small intestine, duodenum. It then penetrates the intestinal wall and gets into the peritoneal cavity.
It finds the liver and starts eating liver cells. This happens only a few days after the initial contact with the parasite. Usually the larva spends a few weeks just browsing and eating the liver. Then it relocates to the bile duct where it begins its final stage and becomes an adult.
It takes about three months for the metacercaria to develop into an adult. Adults are about 3 cm long and 1 cm wide. Adult females can produce up to eggs per day. In the chronic phase of fascioliasis adults in the large biliary ducts cause liver inflammation and obstruction of the biliary fluid. During the migration of the larvae this acute phase of the disease lasts many weeks symptoms include: diarrhea eosinophilia high number of white blood cells fever.
Distribution[ edit ] Fasciola gigantica causes outbreaks in tropical areas of southern Asia, Southeast Asia, and Africa. The geographical distribution of F. Infection is most prevalent in regions with intensive sheep and cattle production. In Egypt F. Intermediate hosts[ edit ] As with other trematodes, Fasciola develop in a molluscan intermediate host. Species of the freshwater snails from the family Lymnaeidae are well known for their role as intermediate hosts in the life cycle of Fasciola gigantica; however, throughout the years an increasing number of other molluscan intermediate hosts of F. The species of Fasciola can become adapted to new intermediate hosts under certain conditions at least based on laboratory trials.
Fasciola Hepatica - Liver Fluke
In addition to humans it infects cows and sheep. It is known as the common liver fluke and causes a disease called fascioliasis. The life cycle of Fasciola hepatica starts when a female lays eggs in the liver of an infected human. Immature eggs are discharged in the biliary ducts and taken out in the feces.