LAB (14, 13)

• TREMATODES/FLUKES

  • flat and leaf-like except schistosomes (cylindrical and elongated)
  • all are hermaphroditic except schistosomes
  • all eggs are operculated except schistosomes
  • life cycle: EGG, LARVA, ADULT
  • Mode of transmission: ingestion except schistosomes (skin-penetration)
  • TREATMENT: Praziquantel
• Fasciola treatment

  Bithionol
• Liver flukes

  Fasciola hepatica
• Fasciola hepatica

  • sheep liver or blood liver fluke
  • final host: sheep
  • accidental host: man
• F.hepatica egg

  • large, operculated, unembryonated, yellowish-brown egg
  • resembles hen's egg shape
• F.hepatica adult

  • has cephalic cone and well-developed shoulder
• fasciola gigantica

  giant liver fluke or tropical liver fluke
• Clonorchis sinensis

  chinese liver or oriental liver fluke (most important)
• Opistorchis felineus

  cat liver fluke or siberia liver fluke
• Dierocodium dentriticum

  lancet fluke cirrhosis or fibrosis of the liver
• Paragonimus westermani

  • lung flukes
  • oriental lung fluke
  • mode of transmission: ingestion of contaminated crab
• P. westermani egg


  operculated with shoulders
• P. westermani adult

  resembles coffee bean
• Blood flukes

  Schistosomes

  Schistosoma japonicum
• Schistosomes

  • the adult stage in blood vessels
  • most romantic parasites
  • adult male with gynecophoral canal where female is held
• Schistosoma japonicum

  • commonly named as oriental blood fluke
  • habitat: superior mesenteric vein of small intestine
  • drug choice: Praziquantel
• S. japonicum egg

  • unoperculated, embryonated
  • smallest egg
  • with small knob-like or small-lateral spine
• cestodes

  white, yellowish in color or creamy white in color

  • flat/ ribbon-like
  • mode of transmission: oral route
  • treatment: Praziquantel
• False tapeworm

  Ova: oval, operculated, immature

  Intermediate host: (1st) crustaceans, cyclops (2) freshwater fish

  Species of interest: Diphyllobothrium latum
• True tapeworm

  Ova: spherical, non-operculated, embryonated with hexacanth embryo

  Intermediate host: lower forms of mammals or arthropods

  Species of interest: Taenia solium, Dipylidium caninum
• Taenia solium

  • pork tapeworm
  • habitat: small intestine
  • mode of transmission: ingestion of contaminated pork
  • treatment: Mebendazole and Albendazole
• T.solium egg

  spherical, striated, embryonated eggs with oncosphere
• T.solium adult (upper part)

  • Scolex
  • Rostellum
  • Suckers
  • Neck
• for the successful treatment of T.solium, scolex must be removed
• T.solium adult (lower part)

  • Proglottid
  • three divisions: Immature, mature, and gravid/ripe
• Taenia saginata

  beef tapeworm
• Taenia asiatica


  also known as taiwanese taenia
• Dipylidium caninum

  dog/cat tapeworm

  
  

  mode of transmission: ingestion of flea containing larva
• D.caninum eggs

  enclosed in egg packet/capsule that contains 8-15 embryonated eggs
• Hymenolepis nana


  also known as the dwarf tapeworm
• Hymenolepis diminuta

  also known as the rat tapeworm
• Echinococcus granulosus

  shortest tapeworm with only 3 segments
• Diphyllobothrium latum

  also known as Broad or Fish tapeworm; the largest tapeworm of man
• nematodes

  • is elongated, cylindrical worm, primarily bilaterally symmetrical
  • with hooks, teeth, plates, and papillae
  • have complete digestive tract
  • ENTRY: mouth; DISPOSAL: anus
• nematodes life cycle

  Egg - Larval - Adult
• General appearance of nematodes (male)

  small, curved posterior with spicule
• general appearance of nematodes (female)

  larger, pointed posterior, no spicule found
• female worms capability of producing egg

  • oviparous - lay immature eggs
  • oviviparous/ovoviviparous - lay mature eggs
  • viviparous - lay larva
• adult worms in small intestine (habitat)

  • Capillaria
  • Ascaris lumbricoides
  • Stronglyoides stercoralis
  • Hookworms
  • Trichinella spiralis
• adult worms in large intestine (habitat)

  • Enterobius vernicularis
  • Trichuris trichiura