1. Heterophyiasis

2. Scientific classification
Kingdom: Animalia Phylum: platyhelminthes Class: Trematoda Subclass: Digenea Order: Opisthorchiida Family: Heterophidae Genus: Heterophyes Species: H.heterophyes

3. Heterophyes heterophyes: is parasitic flatworm of class Trematoda It is a minute intestinal fluke with different shape It infects small intestine of various eating mammals including humans Heterophyes heterophyes Hetero= different Phyes= shapes Geographical distribution: -Egypt. -Middle East

4. Morphology
Adult morphology: Minute teardrop-shaped flukes or pyriform ,pear shape spines cover the cuticle anterior Size: 1.5-3mmx 0.5 mm. Suckers: three suckers –Oral sucker: small. – Ventral sucker: large. –Genital sucker (gonotyle): postero-lateral to ventral sucker

5. At the posterior end of the fluke are two oval testes
At the posterior end of the fluke are two oval testes. The vas deferens leading from the testes expands to form a seminal vesicle and then narrows again to form an ejaculatory duct. The fluke also has female reproductive organs. Located medioposterior is the fluke's one ovary and leading away from the ovary is the vitellaria. The uterus is a long tube like structure that also leads away from the ovary and joins up with the ejaculatory duct to form the genital duct which leads to a genital sinus. The sinus leads to the genital pore which is lined with toothed spines

8. Eggs
Cercaria
The genital pore is where the fluke releases its eggs Size: 30 ×15 µ. Shape: oval. Shell: thick. Special character: operculum at one pole and a small knob at the other. Colour: golden yellow. Content: mature (miracidium).
-Body: 2 suckers, primitive gut, 2 dark eye spots, 7 pairs of penetration glands. -Tail: with membrane along one side, the tip and the terminal 1/3 of the other side, pipe like. (Lophocercous cercaria).

9. Egg
Cercaria

10. Life cycle Habitat: adult embeded between villi of small intestine.
Definitive host: man.
1st I.H.: snail, Pirenella conica.
2nd I.H.: Mugil (Boury) and Tilapia (Bolty) fish.
Reservoir hosts: cats, dogs and any fish eating
mammals.
Infective stage: encysted metacercaria in the
muscles and their fins , gills and scales .

11. The adult flukes live burrowed between the villi of the host's small intestine The eggs that are laid contain a miracidium but do not hatch until they are ingested by a snail (Cerithideopsilla Conica Inside the snails gut, the miracidium becomes a sporocyst which then begin to produce rediae. The rediae produce cercariae which then exit the snail, swim toward the surface of the water

12. they contact a fish and penetrate into the epithelium of the fish
they contact a fish and penetrate into the epithelium of the fish. Here, the cercariae encyst in the muscle tissue. The second intermediate host include freshwater fish: Mugil cephalus, Tilapia nilotica, Aphanius fasciatus, and Acanthogobius sp. The definitive host, such as humans or birds, eats the undercooked or raw meat of a fish and ingest the parasite. Natural definitive hosts are cats, dogs, foxes, wolves, pelicans, and humans.

13. Stages in life cycle: egg → miracidium → sporocyst → redia → cercaria → encysted metacercaria → adult. -Eggs appear in stool 2-5 weeks after infection

16. Pathogenicity and clinical signs
heavy infections which are common cause damage to the mucosa and produce intestinal pain and mucosa diarrhea inflammation, superficial ulcers and necrosis . Sometimes eggs can enter the blood and lymph vascular systems through mucosa go into the ectopic sites in the body. 1-The heart can be affected with tissue reaction in the valves and myocardium that cause heart failure. 2-Eggs can also get into the brain or spinal cord and cause neurological disorders and sometimes fatalities 3-lung :nodular shadows, mistaken for T.B.

17. Diagnosis
1. Clinical. 2. Laboratory: by detection of the characteristic mature eggs in stool. 3. Eosinophilia. 4. Extra-intestinal heterophyiasis diagnosed after surgical removal of parasitic granuloma.

18. Treatment -Yomesan (Niclosamid). Prevention and control
-Praziquantel (Biltracid).
-Yomesan (Niclosamid).
Prevention and control
• Avoid defecation in water.
• Avoid eating raw, insufficient cooked fish or
salted less than 10 days.
• Proper grilling of fish.
• Fried fish is safe.
• Periodic examination of fishermen stool for
Heterophyes eggs.
• Mass treatment of infected cases.
• Snail control.