Trematodes - Flukes

  1. Trematodes - Flukes
    • Dorsal - ventral flattened worms
    • Requires one or more hosts
    • Adults have oral sucker at the anterior end and a ventral sucker
    • *ALL intestinal trematodes require a freshwater snail as an intermediate host.
  2. Liver Flukes
    • Fasciola hepatica - sheep liver fluke
    • Clonorchis sinensis - Chinese liver fluke
    • Opisthorchis species
  3. Liver Fluke: F. hepatica

    Life Cycle
    • Eggs shed in stool of sheep,goats,cattle
    • Miracidium devolps, hatches & infects snail (intermediate host)
    • Cercariae develop in snail and are released onto water plants (watercress)
    • Man eats water plant.
    • Larvae enter liver, mature and produce eggs
  4. Liver Fluke: F. hepatica

    Epidemiology/clinical disease/ Diagnosis
    Worldwide - most common in peru,Ecuador, Bolivia, Egypt, France, Iran, & Portugal

    flu like symptoms plus abd pain, jaundeice, etc.

    Egg: unembryonated, operculated, large, ovoid (130-150 x 63-90)
  5. Liver Fluke: C. sinensis

    Life Cycle
    • Adult worms lay eggs in bile ducts & pass via the bile into stool.
    • Eggs ingested by snail
    • Miracidium hatches and infects snail.
    • Larval forms develop 
    • Cercariae released in freshwater fish
    • Man eats undercooked fish
  6. Liver Fluke: C. sinensis (Chinese Liver Fluke)

    • Recovery of characterisitic egg in stool, duodenal, or biliary drainage.
    • Egg: Ovoid, thick brownish/yellow shell, operculum with distinct shoulder, comma shaped appendage at the obopercular end

    Seen in China,Singapore,Malaysia, Taiwan,Japan,Vietnam
  7. Liver Fluke: Opisthorchis species:
    • Location: Laos & Thailand
    • Diagnosis: Recovery of eggs in stool
    • Undifferentiated from C. sinensis.
  8. Intestinal Flukes:
    • Fasciolopsis buski - Giant
    • Metagonimus yokogawai
    • Heterophyes hterophyes
  9. Intestinal Fluke: f. buski

    GIANT intestinal fluke

    Life Cycle
    • Metacercariae are on water plant eaten by human.
    • Adult in small intestine
    • Excyst in duodenum
    • Unembryonated eggs passed
    • embryonated eggs in water infect snail
    • free swimming cercariae infect plants
  10. Intestinal Fluke: f. buski

    Epidemiology /clinical disease
    • Ingestion of contaminated bamboo shoots or water chestnuts.
    • *Resovoir hosts include dogs,pigs,& rabbits
    • Location: SE Asia,China, Southwest Pacific
    • light to heavy infections
  11. Intestinal Fluke: f. buski

    • Recovery of eggs in still
    • Adults in heavy infection
  12. Intestinal Fluke: M. yokotawai

    Life Cycle & Location
    • Ingestion of undercooked fish
    • Excyst & Adult reside in small intestine
    • Embryonated egg is passed in stool

    Location: China, Indonesia, Israel, Korea, Japan, Russia,Spain, & Taiwan
  13. Intestinal Fluke: M. yokotawai

    Clinical Disease
    Light to heavy

    Eggs may infiltrate the lymphatics & intestinal capillaries and be carried to the brain, spianl cord, myocardium where emboli or granulomatous reactions may ocucr
  14. Intestinal Fluke: M. yokotawai

    • Recover of eggs in stool
    • * similary to others. Only way to differentiate is by pt travel hx, or recovery of the adult fluke (rare).
  15. Intestinal Fluke: H. heterophyes

    Life Cycle
    • Ingestion of undercooked fish.
    • Adults & Excyst reside in small intestine
    • Embryonated eggs with fully developed miracidium are pased in feces.
    • snail/cercariae/fish
  16. Intestinal Fluke: H. heterophyes

    Diagnosis / Location
    • Recovery of eggs in stool
    • Not differentiated unless fluke found.

    Philippines, Tunisia, Turkey, China, Sudan, same as others...
  17. Lung Fluke: Paragonimus westermani

    Oriental lung fluke

    Epidemiology & clinical disease
    Location: Asia

    • Symptoms vary depending on worm burden:
    • Eosinophilia, cough, chest pain, hemoptysis with foul fish odor
  18. Lung Fluke: Paragonimus westermani

    Life cycle - Man is definitive host
    • Ingestion of raw/undercooked crabs, cray fish
    • Excyst in duodenum
    • Adults in cystic cavities in lyngs & lay eggs
    • Unembryonated eggs are Coughed up and spit out or swallowed and passed in stool
  19. Lung Fluke: Paragonimus westermani

    • Recovery of eggs in sputum or stool
    • brownish/yellow unembryonated ovoid eggs
  20. Blood Flukes:
    • Schistosoma haematobium
    • S. mansoni
    • S. japonicum
  21. Blood Flukes Life Cycle
    • These are different from other trematodes - 
    • Transmission is by penetration of intact skin by cercariae rather than ingestion
  22. Blood Fluke : Bladder Fluke: S. haematobium

    Bilharziasis, urne schistosomiasis, blood in urine, dysuria, tissue granulomas in bladder

    Africa & Middle East

    Diagnosis: Eggs in Urine (spine in center)
  23. Blood Fluke: S. mansoni

    Swamp Fever, intestinal schistosomiasis

    Africa, S. America, Caribbean, W Indies

    Diagnosis: Eggs in stool (spine off center)
  24. Blood Fluke: S. japonicum

    • Oriental Blood Fluke
    • Disease:Katayama, Yangtze River Fever

    Diagnosos: eggs in stool (round no spine)
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Trematodes - Flukes
Trematodes - flukes