FINALS

• Trematodes


  Parasitic flatworms that infect humans

  
• Paragonimus westermani


  Oriental lung fluke
• Paragonimus westermani ova


  • Large; operculated with abopercular thickening (posterior end)
• Paragonimus westermani adult


  • Coffee bean shaped; w/ lobed 2 testes side by side; simple intestines
• Monoecious and hermaphrodite


  Both sexes present in one species
• Life cycle of Paragonimus westermani

  1. Eggs released from stool

  2. Hatch in water

  3. Miracidium enters snail intermediate host

  4. Develops into sporocysts, rediae, cercariae

  5. Cercariae infect second intermediate host (food item)

  6. Ingested by human definitive host

  7. Excystation and development in human host

  
• Infective stage of Paragonimus westermani

  • Metacercaria
• Mode of transmission


  Ingestion of second intermediate host (food item)
• Hosts of Paragonimus westermani

  • 1st intermediate host: Brotia asperata (snail)

  2nd intermediate host: Sundathelphusa philippina (freshwater crab)

  Definitive host: Humans

  Paratenic host: Wild boar

  
• Diseases caused by Paragonimus westermani

  Hemoptysis (coughing out blood)

  Paragonimiasis (signs and symptoms of tuberculosis)
• Fasciola hepatica


  Sheep liver fluke
• Fasciola hepatica ova


  • Large with operculum, w/ cephalic cone; distinct shoulder
• Fasciola hepatica adult


  • Dendritic (branched): intestines, testes, ovary; The inner portion forms are so crowded
• Life cycle of Fasciola hepatica


  Similar to all trematodes
• Infective stage of Fasciola hepatica

  • Metacercaria
• Hosts of Fasciola hepatica

  • 1st intermediate host: Lymnaea sp (snail)

  2nd intermediate host: Ipomoea sp (freshwater vegetation)

  Definitive hosts: Humans, Cattle

  
• Diseases caused by Fasciola hepatica

  Fascioliasis (biliary obstruction)

  Halzoun (suffocation from temporary lodgement in pharynx)
• Sheep/goat livers are eaten raw, which may be infected with adult Fasciola
• Diagnosis of Fasciola hepatica

  Recovery of eggs from stool after 3-day liver-free diet

  To differentiate true from false fascioliasis

  
• Clonorchis sinensis


  Chinese liver fluke
• Clonorchis sinensis ova


  • Small, resembling old fashioned electric bulb with operculum
• Clonorchis sinensis adult


  • w/ simple intestines; 2 testes branched one over the other
• Clonorchiasis


  Infection with Clonorchis sinensis, generally asymptomatic but can cause liver dysfunction when heavily infected
• Opisthorchis felineus is described as a zoonotic parasite
• Consumed liver with fasciola


  Liver that has been ingested by the patient
• After 3 days liver free diet, do another fecalysis


  1. If you see again the egg meaning that is a true fascioliasis

  2. If there is no egg in the stool meaning it is just from the liver that the patient consumed or false fascioliasis
• Also check the history of the patient
• Clonorchis sinensis (Chinese liver fluke)


  • Small resembling old fashioned electric bulb with operculum
  • With simple intestines; 2 testes branched one over the other
• Clonorchiasis


  • Consumption of imported frozen
  • Generally, asymptomatic
  • Causes Clonorchiasis when heavily infected with adult worms (fever, abdominal pain, epigastric pain) eosinophilia, tenderness and enlargement of the liver → liver dysfunction
• Opisthorchis felineus (Cat liver fluke)

  With simple intestines; 2 testes (not well branched) one over the other
• Life cycle of C. sinensis and O. felineus

  1. Eggs are released from the stool

  2. Hatch in the water

  3. Miracidium are being release

  4. Enters the snail intermediate host; the name of the snail would be depending on the species of the trematodes because they are host specific

  5. Develops into 3 different stages: Sporocysts, Rediae, Cercariae - came out from the snail and look out for the next intermediate host; generally, it is a food item

  6. Human take in the food item (ingestion)

  7. There is excystation and develop to the host depending on the species

  
• Life cycle (important notes)

  • Infective Stage: Metacercaria
  • MOT: ingestion
  • Hosts: 1st IH: Bolinus sp. Parafossarulus sp ; 2nd IH: Cyprinoid fish (tilapia)
  • DH: Man
  • RH: Dogs, Cats
  • Habitat: Liver

  
• Intestinal flukes


  • Fasciolopsis buski
  • Echinostoma ilocanum
  • Echinostoma malayanum
  • Heterophyes heterophyes
  • Metagonimus yokogawai

  
• Fasciolopsis buski (Giant intestinal fluke)


  • Large with operculum
  • Longer than Fasciola hepatica
  • With simple intestines, branched testes, ovary
• Life cycle of Fasciolopsis buski

  Similar to all trematodes
• Life cycle (important notes)

  • Infective Stage: Metacercaria
  • MOT: Ingestion
  • Host: 1st IH: Lymnea sp; 2nd IH: Water chestnuts; water bamboo; water caltrops
  • Definitive Host: Man; pig; cattle
  • Habitat: Small intestine

  
• Fasciolopsiasis


  • Abdominal discomfort ; irritation at the site of attachment in the small intestine ; inflammation and bleeding of the affected area, diarrhea (malabsorption)
• Distribution: Thailand, Taiwan, Vietnam, India, Indonesia, some parts of China
• Echinostoma ilocanum (Garrison's fluke)


  • With minute operculum
  • With circumoral disc, 49-51 collarette spines; (50 +/- 1)
  • 2 lobed testes one over the other
• Echinostoma malayanum


  With circumoral disc, 43-45 collarette spines (44 +/-1) ; 2 branched testes one over the other