Heterophyes heterophyes
| Heterophyes heterophyes | ||||||||||||
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Egg of Heterophyes heterophyes |
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| Scientific name | ||||||||||||
| Heterophyes heterophyes | ||||||||||||
| ( Siebold , 1853) |
Heterophyes heterophyes is aparasite belongingto the flukes . It was discovered in 1851 by Theodor Bilharz during an autopsy in the small intestine.
features
In the adult stage, this small, hermaphroditic intestinal leech has an elongated ovoid body shape with a size of 1.0–1.7 × 0.3–0.7 mm. When alive, it is gray in color. The tegument is occupied by fine thorns, which are particularly numerous anteriorly (towards the front). The oral suction cup with a diameter of 90 µm is significantly smaller than the abdominal suction cup in the middle third of the body with a diameter of 230 µm. A genital suction cup (150 µm) is located on the left, rear edge of the abdominal suction cup. The edge of this additional genital suction cup (also known as the gonotyl or genital acetabulum), a peculiarity of the Heterophyidae family, is covered with tiny thorns and distinguishes Heterophyes heterophyes from Metagonimus yokogawai . The digestive tract includes a narrow prepharynx, a small, bulbous pharynx , a narrow esophagus, and two blindly ending intestines. A third body length from the end of the body away is the rounded ovarian , two oval balls are adjacent the end of the body. The eggs that contain the Miracidium have dimensions in the order of 30 × 17 μm and are similar to those of the genus Opisthorchis .
distribution
Heterophyes heterophyes is common in Asia, North Africa, the Middle East and southern Europe. The main distribution areas are Egypt, Iran and Korea.
Development cycle and infestation
The embryonated eggs of the intestinal leech are excreted with the faeces and removed by marine gill snails such as z. B. Potamides conicus ( Syn .: Pirenella conica ) ingested with food (first intermediate host ). After a sporocyst stage and two editing stages , the cercariae develop and penetrate fish such as the mullet (second intermediate host). In the fish they encyst as metacercariae . If the fish are then eaten raw or not sufficiently cooked , the adult intestinal leeches develop from the metacercariae in the host at the end of the development cycle.
People or fish-eating animals are attacked, the intestinal leech colonizes the wall of the small intestine ( jejunum and anterior ileum ) and is often found in the Lieberkühn crypts .
illness
The disease is often asymptomatic; If there is a massive infestation of thousands of worms, flat ulcers and inflammations develop, which manifest themselves in abdominal pain and digestive complaints up to diarrhea . The eggs can penetrate blood vessels, be transported to organs such as the heart, spinal cord or brain and cause damage, for example by occluding the heart vessels. The diagnosis is made by detecting the eggs. Praziquantel is used for treatment after niclosamide was used in the past .
As a prophylaxis , fish in question (for example from the Nile Delta or Lake Manzala ) should be fully cooked. Avoiding contamination of the water with feces could be a possible longer term goal.
literature
- Gerhard Wiedermann, Herbert Auer: Pathophysiology, Immunology, Clinic and Therapy of Worm Diseases , 2006, p. 78f
- Burton Jerome Bogitsh, Clint Earl Carter, Thomas N. Oeltmann: Human parasitology , 2005, pp. 215f
- Dwight D. Bowman: Feline clinical parasitology , 2002, pp. 133f
- Ralph Muller, Derek Wakelin: Worms and human disease , 1975 pp. 51f
Individual evidence
- ↑ a b c Wiedermann, Auer, pp. 78–80.
- ↑ a b c d e Ralph Muller, Derek Wakelin: Worms and Human Disease. CAB International, 2002, ISBN 978-0851995168 , p. 52.
- ^ A b c Richard Lucius, Brigitte Loos-Frank: Biology of Parasites. Springer, 2007, ISBN 978-3540377078 , p. 284.
