Cestodes

• Dibothriocephalus Latus


  Largest tapeworm
• Diphyllobothrium latum


  Old name for Dibothriocephalus latus
• Diphyllobothrium nihonkaiense


  Tapeworm from raw fish in Japan
• Diplogonoporus


  From raw anchovies in Japan and Korea
• Dibothriocephalus latus resembles Paragonimus westermani egg


  Both operculated, however thickening is more prominent in P. Westermani
• Dibothriocephalus latus


  • Wrinkled, whitish, ribbon-shaped organism
• Broad Fish Tapeworm


  Common name for Dibothriocephalus latus
• Sparganum


  Infective stage
• Infective stage to 1st intermediate host

  L1- Coracidium
• Infective stage to 2nd intermediate host

  L2- Procercoid larvae
• Infective stage to 3rd intermediate host

  L3-Plerocercoid larvae
• L2 - Procercoid larvae


  Causes the Sparganosis
• L3 - Plerocercoid larvae


  Infective stage
• Dibothriocephalus Latus


  1. 10 meters
• Eggs


  • 70x50um
  • Oblong, yellowish-brown
  • EMBRYO: Underdeveloped, CORACIDIUM
  • OTHER FEATURE: Operculated; with terminal knob (Abopercular knob/ knob-like thickening)
• Scolex


  • # of sucking grooves: 2 'bothria'
  • Shape of scolex: Spoon-shaped/ almond shape, spatulate shaped
• Mature


  • Wider than long
  • 1 set of male and female
• Gravid


  • Rosette-like uterus shen filled with eggs
• Taenia solium


  Pork Tapeworm
• Taenia Saginata


  Beef tapeworm
• Taenia saginata asiatica


  Asian Tapeworm
• Apolysis: Taenia solium


  • sheds in group
• Apolysis: Taenia Saginata

  • shed individual
• Taenia saginata asiatica

  • First reported in taiwan
  • Morphologically similar to T.saginata but scolex resembles T. Solium
  • Does not produce cysticercosis in humans (like T. saginata)
• Eggs


  • Composed of: EMBRYOPHORE: Thick radially striated coat
  • With oncosphere inside
  • Six (6) hooked embryo
  • Indistinguishable between T. Solium and T. Saginata
• Taenia solium Scolex

  • 25-30 large & small hooklets
  • 4 muscular suckers
  • Armed rostellum with double crown/rows
• Taenia solium Mature Proglottids


  • Wider than long
  • 1 set of male and female organ
  • Trilobed ovary with accessory ovarian lobe
• The eggs of cestodes are usually ingested by an intermediate host, where they hatch and develop into larvae that can infect the definitive host upon ingestion.
• The life cycle of T. saginata involves ingestion of undercooked beef containing cysticerci, which develop into adult worms in the small intestine.
• The life cycle of T. saginata involves ingestion of undercooked beef containing cysticerci, which develop into adult worms in the small intestine.
• Once inside the definitive host, the larvae mature into adult tapeworms that attach to the host's intestines and reproduce, completing the life cycle.
• Cysticercosis is the most common infection caused by Taenia solium, with an estimated 50 million people infected worldwide.
• Cysticercosis is the most common infection caused by Taenia solium, with an estimated 50 million people infected worldwide.
• Cestodes have a complex life cycle that typically involves two hosts, an intermediate host where larvae develop, and a definitive host where adult tapeworms reside.
• Eggs hatch in the small intestine and develop into adult worms, producing eggs that are passed out in feces.
• Taeniasis is an infection caused by T. saginata, which can be acquired through consumption of raw/undercooked beef.
• Hydatidosis is caused by ingestion of contaminated water or food containing eggs of Taenia solium.
• Taeniasis is an infection caused by T. saginata, which can be acquired through consumption of raw/undercooked beef.
• Eggs hatch in the small intestine and develop into adult worms, producing eggs that are passed out in feces.
• Taeniasis can be diagnosed through fecal examination or serology tests.