Heterophyes heterophyes

Egg of Heterophyes heterophyes

Heterophyes heterophyes is a parasite belonging to the trematodes. He was discovered in 1851 by Theodor Bilharz at an autopsy in the small intestine.

Features

This small, hermaphrodite intestinal fluke in the adult stage has a stretched ovoid body shape with a size of 1.0-1.7 × 0.3-0.7 mm. Alive he is gray in color. The tegument is occupied by fine spines, which are particularly numerous anterior ( towards the front ). The oral sucker is 90 microns in diameter significantly smaller than the located in the middle third of the body ventral sucker with 230 microns. A genital sucker (150 microns ) is located at the left rear edge of the abdominal sucker. The edge of this extra genital sucker (also called Gonotyl or genital acetabulum ), a special feature of Heterophyidae family is filled with minute spines and different Heterophyes heterophyes of Metagonimus yokogawai. The digestive tract comprises a narrow Präpharynx, a small, bulbous pharynx, esophagus, and close two blind-ended intestines. A third body length from body end away is the roundish ovary, two oval testes lie next to each other at the end of the body. The eggs containing the miracidium, have dimensions in the order of 30 × 17 microns and are similar to those of the genus Opisthorchis.

Dissemination

Heterophyes heterophyes is widespread in Asia, in North Africa, the Middle East and southern Europe. Main distribution areas are Egypt, Iran and Korea.

Development cycle and infestation

The embryonated eggs of the intestinal fluke are excreted in the faeces and of marine prosobranch such as Potamides conicus ( Syn: Pirenella conica ) consumed in the diet (first intermediate host ). After a Sporozystenstadium and two Redienstadien the cercariae, which penetrate into fish like the big-headed mullet occur (second intermediate host ). In the fish they encyst as metacercariae. If the fish are then eaten raw or inadequately cooked, the development cycle of the metacercariae develop inside host to complete the adult intestinal flukes.

There are people or fish-eating animals infested with the intestinal fluke colonizes the small intestine wall ( jejunum and ileum front ) and is often found in the crypts of Lieber.

Disease

The disease is often asymptomatic; with massive infestation of thousands of worms arise shallow ulcers and inflammation making in abdominal pain and indigestion through to diarrhea noticeable. The eggs can penetrate into blood vessels, are transported to organs like the heart, spinal cord or brain and cause, for example, by closing the cardiovascular damage. The diagnosis is made on the demonstration of eggs. For treatment of praziquantel is used, after they had previously used niclosamide.

As prophylaxis should be completely cooked through ( for example from the Nile Delta or from the Lake Manzala ) Candidate fish. The avoidance of contamination of the water with feces could be a possible longer- term goal.