Fasciolidae

A brief description of trematodes of family Fasciolidae, their morphology, pathogenesis, clinical signs, diagnosis, treatment and control.

1. Family: Fasciolidae Dr. Ishfaq Maqbool Ph. D. scholar Veterinary Parasitology GADVASU

2. Classification Phylum: Platythelminthes Class: Trematoda Sub-class: Digenea Family: Fasciolidae Genus: Fasciola Fasciolopsis Fascioloides Parafasciolopsis

3. Morphology Large flukes present in bile ducts and intestine of mammals Cuticle is spined , suckers closely approximated, caeca long, simple or much branched Testis as well as ovaries are branched Eggs are thin shelled and operculated

4. Fasciola hepatica : Morphology 3-5 cm long and 1 cm wide. Cuticle is spiny At anterior end there is a cone like projection followed by broad shoulders. The oral sucker at the anterior tip while the ventral sucker at the level of shoulder. Intestinal caeca are branched. Testis are branched and tandemly placed. Ovary is branched and anterior to the testis. The field between the ovary and the ventral sucker occupied by uterine coils which leads to the genital pore. Vitelline glands are scattered at the lateral field

5. Fasciola gigantica : Morphology Bigger than Fasciola hepatica (5-7cm in length). At anterior end cone is less prominent than Fasciola hepatica. Cuticle spiny. Internal morphology is same as Fasciola hepatica.

6. Life cycle

7. . Life Cycle Egg

8. Life cycle… Egg : Yellowish brown in colour, oval operculated. Bile imparts the yellow colour to the egg. Hatching depends on atmospheric temp. At room temperature, majority of eggs hatch within 10-12days. Miracidium hatches only if stimulated by light and if water surround the egg After hatching the miracidae stages comes out Moves vigoursly in water to detect fresh water snail, by chemotaxis . Parasite Intermediate host Fasciola hepatica Lymnaea truncatulla Fasciola gigantica L.accuminata , L.auricularia , L.rufescens

9. Life cycle… After contact has been made, usually with the foot of the snail, they burrow using enzymes and then lose their ciliated outer layer to form sporocyst . Each sporocyst give rise to 5-8 rediae stages Redial stages has a oral aperture, pharynx and sac like gut. There is a pair of blunt process behind the body. There is a birth pore through which several Gymnocephalous cercariae released in the atmosphere. Miracidium Rediae

10. Life cycle… Gymnocephalus cercariae are liberated from the body of snail which adheres on the solid surface and the grass blade, it then losses its tail and secretes a protective cyst wall. This encysted cercaria is called as metacercariae Infection to the definitive host is through ingestion of metacercaria while grazing on low line pasteur Metacercariae which are settle at the bottom of lake/pond gets stirred up & swallowed up along with drinking water when larger host like cattle & buffalo enter. Cercariae Metacercariae

11. Life cycle… Excystation in Small Intestine due to action of bile and acid pepsin Immature flukes emerges Penetrate the mucosa and the wall of intestine. Enter peritoneal cavity, goes to liver Penetrate liver capsule (4-6 days post infection) Some flukes reach liver via hepatoportal circulation. However most common route is peritoneal cavity. After entering liver, immature flukes migrates in the liver parenchyma for 5-6 weeks. Eventually assemble in bile duct, matures, lays egg. Adult flukes are sluggish, feed on bile duct mucosa, blood & bile Survive for many years in sheep but not in cattle

12. Life cycle… Prepatent period: 8 weeks Undeveloped egg to miracidium : 9 days Entry in snail to exist of cercaria : 5 weeks Ingestion of metacercariae to formation of egg 6-12 weeks. Egg to egg: 14 ½ weeks.

13. Factors influencing the Life cycle Atmospheric temperature : 10-26ºC optimum temperature. Below 12ºC, no development of miracidium . At 12ºC -20ºC, increase in development inside egg. For egg at 12ºC- 60 days for eggs to hatch 15ºC- 42 days for eggs to hatch 26º C– 27ºC – 12 days for eggs to hatch Above 27ºC : Snail mortality and larval stages can`t survive in the snail.

14. Morphology 2. Snail Ecology: Lymnaea spp. of snail act as intermediate host. Ubiquitous and amphibious in nature Longevity of snail is 12 months Snail hibernation results in arrested development of developing stages Size of snails plays important role and not number. Summer infection of Snails important

15. Morphology 3. Longevity of metacercariae : Under lab condition survives one year Only 5% remains infective during suitable atm. temp. & moisture and can survive for 3-4 months. As time passes, metacecariae drop down from grass blade. Silage:1-2 months Hay: 8 months Water: 3-4months

16. Pathogenesis Depends on number of infective stage ingested. Not much damage to intestine and peritoneal cavity due to migration of immature stages Principle lesion produced in the liver parenchyma or bile ducts. 2 disease entities: Acute fasciolosis : Less common. Seen in sheep during August & September, since large no. of metacercariae are present on pasture during the month of June & July. Chronic fasciolosis : Common in cattle and buffalo, seen during the month of November & March.

17. Acute fasciolosis Large number of immature stage in subst. of liver Death of host in 4-6 weeks P.I due to destruction of liver parenchyma Haemorrhagic tracts in liver Liver becomes enlarged, pale and friable Fibrinous clots on surface of liver & peritoneal cavity. Generally left lobe commonly affected. At proximal end, hemorrhagic tract & immature flukes present, followed by zone of hemorrhages and zone of reddish grey material of inflammatory cells

18. Acute fasciolosis Immature flukes (0.7 – 2mm) can be squeezed from the cut surface. In massively infected animal large number of metacercariae may rupture the liver capsule leading heavy bleeding in the peritoneal cavity and death

19. Chronic fasciolosis Mainly two types of lesion produced 1. Hepatic Fibrosis 2. Hyperplastic cholangitits Hepatic Fibrosis : Due to migration of immature fluke in liver parenchyma Migratory tract, area of haemorrhages and necrosis Thrombus formation Area of coagulative necrosis Healing by regeneration of parenchyma Marked fibrosis FCT matures Scarring and distortion of hepatic parenchyma. FCT proliferation divides liver in to small lobule

20. Chronic fasciolosis 2. Hyperplasic cholangitits Presence of adults flukes in the bile duct cause irritation to bile duct epithelium. Causes of irritation is due to: Spines on cuticle and suckers Release of toxic metabolites of parasites Retention of bile Inflammation, Hyperplasia and Denudation of bile duct epithelium which is replaced by FCT

21. Chronic Fasciolosis In large ruminants, Calcification of fibrotic lesion ( calicification of bile duct). Clay Pipe Liver or Pipe Stem liver : Protrusion of Bile duct out from the surface of liver giving appearance of Stem of Clay pipe . Microscopically, lesions can be described as hyperplastic cholangitits with progress biliary cirrhosis. Occasionally, eggs of Fasciola trapped in tertiary bile duct causes granulomatous lesions. Rarely flukes may settle in Subcutaneous tissues or lungs enclosed in cyst with yellowish brown cheesy material.

22. Complication of Fasciolosis Seen in sheep due to presence of Clostridium novyi in intestine. Clostridium novyi carried by the immature flukes to the liver where are of coagulative necrosis are produced These anaerobes multiply and produce disease called as the Black disease.

23. Clinical pathology Two types of clinical findings: Anaemia Hypoproteinaemia Anemia is due to Haematophagous activity of adult flukes (0.5 ml/day) and hemorrhagic tracts by immature flukes Initially anemia is initially normochromic normocytic and later hypochromic macrocytic Hypoproteinaemia ( Hypoalbuminaemia ):Due to 1. Destruction of hepatic parenchyma by immature fluke Liver is principle site of synthesis of albumin. Due to migration of flukes synthesis affected. 2. Preferential use of aminoacids for synthesis of globulin results in hypoalbuminaemia .

24. Symptoms 1. Acute Fasciolosis: No specific symptom. Sudden death. Blood tinged from nostrils, mouth as well as bloody discharge from anus. 3. Chronic Fasciolosis Anaemia Pale mucus membrane Anorexia Emaciation Edema of dependent part “Bottle Jaw condition” Skin becomes dry and rough Wool falls off in patches Irregular peristalsis ( Diarrhoea or constipation) 2. Sub Acute Fasciolosis: Anorexia Disinclination to move Distention of abdomen Pain on palpation If not treated on time, animal may die due to infection.

25. Diagnosis Chronic Fasciolosis: S.S.E (stool sample examination) for detection of Fasciola egg. Acute Fasciolosis: Based of symptoms in endemic areas Incase of death, perform Post Mortem On necropsy, liver shows traumatic hepatitis with migratory tracts. Cut liver into thin slices, place in Luke warm saline, Flukes will wriggle out

26. Immunity in Fasciolosis Sheep is most susceptible to Fasciola infection because they donot develop protective immunity against subsequent infection. Cattle and Buffalo: Immunity develops In C & B vaccination can be targeted but not in Sheep and goat. Experimental feeding of irradiated metacercaria to showed encouraging results. No commercial vaccine available till date.

27. Human Fasciolosis Consumption of metacercariae through uncooked/unwashed leafy vegetables. Fluke settles in S/C tissue and lungs, forming a granulomatous mass.  Symptoms : Gastrointestinal problems such as nausea, vomiting, and abdominal pain/tenderness. Fever, rash, and difficulty breathing may occur. Inflammation of the liver, gallbladder, and pancreas also can occur. Treatment : Bithionol@50mg/kg body weight every alternate days for 15 days

28. Treatment of Fasciolosis 1.Carbon tetrachloride given orally @ 1-3ml in sheep/goat and 1-5 ml in large ruminant. Should be given in gelatin capsule or should be mixed with Liq. Paraffin oil in equal quantity. Effective against adult flukes Use discontinued, since it is Hepato and nephrotoxic . Chances of toxicity reduced when given deep i / m injection but there is formation of abscess at the site of injection.

29. Treatment… Hexachlorethane given @ 220-400mg/kg body weight against Adult flukes Hexachlorophene given orally or s/c @15-20mg/kg against adult flukes. Hetol@150mg/kg body weight against chronic fasiciolosis Bitihonol @ 40mg/kg body weight effective against chronic fasciolosis. Oxyclozanide @15mg/kg body weight in chronic cases. In acute cases increase the dose 3 times. Rafoxinide @ 7.5mg/kg body weight Nitroxynil : 10mg/kg body weight given S/c Oxyclozanide @15mg/kg body weight Diamphenethide @ 100mg/kg body weight Albendazole @7.5 mg/kg body weight Oxyfendazole @5 mg/kg body weight Drug of Choice TRICLABENDAZOLE@10-12mg/kg body weight

30. Control Prevention: Prevent the animal from grazing on infected pastures. Destruction of snails: Molluscide : Copper Sulphate i.e. CuSO 4 Destruction of snails on wet pasteur : 1-2% Cuso4 is sprayed or 1 part of CuSO 4 mixed with 4 parts of sand and sprayed on pasteur 10-30 kg/ha. Destruction of snails in water body: In stagnant water, CuSO 4 should be added to make the final conc. 1:50,000 to 1:1,00,000

31. Control For flowing water: CuSO 4 should be placed in non metallic boxes having pores in it. These boxes should be placed at the origin of the streams so that it can kill the snails several km. down the stream. If CuSO 4 is not available then Cupentachlorophenate can be used @ 10lbs/acres. This molluscicide treatment should be repeated every 3-4 months. 2. Biological control: Birds like Free-ranging ducks or geese Echinostome flukes: Ability of larval echinostomes to aggressively displace other larval flukes from their snail hosts and parasitic castration of snails by larval echinostomes ( E. revolutum ) Prophylaxis : No chemoprophylaxis Treatment: Frequent deworming (Pre-monsoon, monsoon, post monsoon)

32. Fasciola jacksoni : Occurs in elephant Severe submandibular and ventral abdominal oedema Anaemia and Hypoproteinaemia Other features same as ovine fasciolosis Nitroxynil (10mg/kg) used for treatment

33. Fascioloides magna Found in cattle, horse, sheep and pigs of north America and in cattle, sheep and deer in Europe. Oval and round posterior end, no anterior cone like projection Eggs with protoplasmic appendage at the pole opposite the operculum Intermediate host: snails of Fossaria spp., Lymnaea spp. and Stagnicola spp .

34. Fascioloides magna… Deer : Family Cervidae normal host. Young flukes migrate extensively and then encapsulated with 2-3 flukes per capsule. Capsules connected to bile duct, eggs passed in faeces. Bovidae : Cattle, Bison, Yak are aberrant hosts Closed cysts, No eggs in faeces and no signs of ill health. Sheep : Also aberrant host. Uninterrupted migration and no encapsulation which is fatal. Treatment: [email protected] mg/kg Rafoxanide@12-25mg/kg albendazole@15-35mg/kg is 90% effective

35. Fasciolopsis buski … Small intestine of Man, pig. The largest one of human trematodes. No shoulders Unbranched intestinal caeca. The ventral sucker is near by the much smaller oral sucker. Branched, tandem testes are located in the posterior half of the body, ovary in right of midline. Intermediate hosts: Planorbis and Segmentina snail which feed on certain plants: water calthrap , Trapa natans and T. bicornis ; and water chestnut, Eliorchis tuberosa fertilised by human night soil 130-140×80-85µ(the largest helminth egg).

36. Fasciolopsis buski … Enteritis or ulcerative lesions due to the attachment of the adults manifests abdominal discomfort, nausea, vomiting and diarrhea. Malnutrition results from the worms sharing food with the host and diarrhea . Manifests anaemia, oedema of leg and face even ascites. Treatment The treatment of the patients, carriers and pigs Drug of choice is praziqantel . Also 1g of hexaresorcinol is highly effective. Other effective drugs include hexachloroparaxylol , bithionol , Tetrachloroethylene , Niclosamide Prevention (1) Health education, (2) Deal with night soil. (3) Avoid feeding pigs on raw water plants

37. Parafasciolopsis fasciolaemorpha: Gall bladder of elk, deer and wild goat in Russia and Poland Spiny cuticle Planorbis snail as intermediate host Heavy infections are lethal to elk

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