Fascioloides%20magna%20

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Fascioloides magna Giant Deer Fluke

• Different behavior and pathology in different
  hosts.

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Fascioloides magna Giant Deer Fluke

• Deer and Elk (normal hosts)Liver migration, then
  matures in thin-walled fibrous cysts connected
  with bile ducts. (Well tolerated eggs shed in
  feces).

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Fascioloides magna Giant Deer Fluke

• Cattle, bison and swineLiver migration, then
  encapsulation in thick-walled, closed cysts and
  no eggs are shed!

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Fascioloides magna Giant Deer Fluke

• Sheep and goats extensive, uninterrupted hepatic
  migration with out encapsulation usually fatal
  1 fluke can kill a sheep or goat!

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Pathology

• Pathology in C. sinensis and D. dendriticum
  distended bile ducts and erosion of epithelium
  lining, but no secondary pathology like in F.
  hepatica!

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Treatment

• Preziquantel (except for F. hepatica).
• Rafoxanide is the drug of choice for F. hepatica!

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Diagnosis

• Look for eggs in feces!
• But hard to diagnose (why?).
• SPURIOUS INFECTIONS!

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Aquatic Vegetation
Water Chestnuts
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Pickled Fish
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Digestive Tract Trematodes
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Fasciolopsis buski

• Order Echinostomatiformes
• Humans, pigs
• Orient
• Large (7.5 cm)
• Life cycle similar to Fasciola

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Pathology and Symptoms

• Severity depends on worm burden
• Irritation
• Excess mucous secretion
• Ulceration, hemorrhage, Abscess
• Obstruction
• Chronic diarrhea
• Sensitization to worm metabolites
• Leukocytosis
• Anemia
• Eosinophilia
• Nausea/diarrhea
• Edema of face and intestinal wall
• Death

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Treatment

• Praziquantel

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Epidemiology

• Who gets infected?
• Rural to semi-urban areas
• School age children
• Prevalence
• 57 China
• 25 Taiwan
• 50 Bangladesh
• 60 India
• 10 Thailand

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Epidemiology

• How do you get fasciolopsiasis?
• Ingest metacercariae
• Commercially raised aquatic plants
• Water chestnut
• Water caltrop
• Water hyacinth
• Water lotus
• Water lily
• Watercress

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Epidemiology

• Lack of regulation on food industry
• Food preparation
• Sanitation (sewage)
• Night soil
• Pigs
• Habitat
• Food

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Digestive Tract Trematodes

• FAMILY ECHINOSTOMATIDAE - intestinal parasites
  recognized by their anterior collar of spines.
•  
• Echinostoma revolutum - Cosmopolitan parasite of
  birds and mammals shows low host specificity
• Human cases?

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Morphology of Adult Echinostoma revolutum
Adults are elongate, up to an inch in
length. Characteristic structure is their
circumoral collar of spines arranged in two
rows. 37 spines in E. revolutum. Internal
organs are distinct and easy to identify.
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Morphology of Adult Echinostoma revolutum
Collar of spines around oral sucker
uterus
Vitellaria Testes Mehlis
gland Ovary
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Life Cycle of Echinostoma revolutum
Parasite shows low host specificity throughout
cycle   1. Adults occur in birds and
mammals.   2. Eggs are released via the feces
into an aquatic habitat.   3. Miracidia hatch,
swim to snail, and penetrate.
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Life Cycle of Echinostoma revolutum
4. Sporocysts and rediae occur within snail.
Cercariae are released. 5. Cercariae penetrate
(2nd intermediate hosts) and encyst as
metacercariae.   6. Definitive host is infected
by ingesting 2nd intermediate host,
metacercariae excyst in stomach, and adults
mature in small intestine.  
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Order Plagiorchiformes

• Family Troglotrematidae these are oval thick
  flukes with a spiny tegument and dense
  vitellaria.
• Parasites of lungs, intestine, nasal passages,
  cranial cavities, and various ectopic locations.

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Nanophyetus salmincola
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Nanophyetus salmincola

• Northwest N. America
• Northeast Asia
• Crypts of the small intestine
• Human infections
• 98 prevalence in Siberian villages
• Pathology

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Nanophyetus salmincola

• Salmon poisoning
• Highly pathogenic
• Neorickettsia helminthoeca
• Rickettsia
• Intracellular bacterium
• Typhus
• Nanophyetus salmincola is a vector for
  Neorickettsia helminthoeca.

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Nanophyetus salmincola

• Disease
• High Fever
• Edema of face
• Vomiting
• Diarrhea
• Death in 10 days to 2 weeks.

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Lung Flukes

• Paragonimus
• bronchiolar lumen and peribronchial tissues
• Antigenic
• Become encapsulated
• granuloma

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Paragonimiasis

• Paragonimus
• 7 species in Asia, Sub-Saharan Africa, Central
  and South America
• Paragonimus westermani

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Life cycle of Paragonimus
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Paragonimus cercaria
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Paragonimus westermani

• 1st Int. Host
• Freshwater snails
• Streams
• Rice paddies

Melanoides tuberculata
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Paragonimus westermani

• 2nd Int. Hosts
• Potamon
• Rice Paddies
• Eriocheir
• Streams
• Larvae develop in brackish water

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Paragonimus kellicotti

• Crayfish serve as 2nd IH in North America.
• Metacercariae are found in the heart.

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Paragonimus

• A number of birds and mammals are know to serve
  as PH!
• Guinea pigs are known to serve as PARATENIC HOSTS
  for Paraganimus spp. in South America!