CESTODES-F

• CESTODES are a type of tapeworm that is found in the small intestine
• Cestodes

  • are hermaphroditic worms, each mature segment, possesses both male and female sex organs,
  • lack a body cavity or digestive system.
  • Adult worms inhabit the small intestine of the definitive host.
  • need intermediate host (except Hymenolepis nana)
• Tapeworms have flat, segmented bodies, consisting of a head, known as the scolex.
• neck and a series of segments known as proglottids or strobila.
• The scolex: Is the organ of attachment and provided with 4 suckers.
• The strobila: consists of immature, mature and gravid segment
• CESTODES

  Intestinal Species

  • Taenia saginata
  • Taenia solium
  • Hymenolepis diminuta
  • Hymenolepis nana
  • Dipylidium caninum
  • Diphyllobothrium latum

  Intestinal-Extraintestinal Species

  • Echinococcus granulosus
• TAENIA SAGINATA aka beef tapeworm
• TAENIA SOLIUM aka Pork tapeworm
• T. species egg morphology:

  28-40um

  3 pairs hooklets

  radial strations on yellow-brown embryophore
• T. saginata adult morphology:

  4 suckers

  absent rostellum and hooks

  longer than wide
• T. solium adult morphology:

  Four suckers

  present rostellum and hooks

  square
• Taenia saginata & Taenia solium Present in areas of the world in which the inhabitants do not practice sanitary conditions and beef or pork is eaten on a routine basis.
• Taeniasis

  • beef or pork tapeworm infection
  • Nondescript symptoms, such as diarrhea, abdominal pain, change in appetite, and slight weight loss In addition, symptoms including dizziness, vomiting, and nausea may also develop.
• Praziquantel

  • has proven effective treatment for T. spp(adult worm) except when there is ocular or central nervous system (CNS) involvement.
• Paromomycin and Quinacrine hydrochloride (Atabrine) may also be used as alternative treatments For T. spp
• HYMENOLEPIS DIMINUTA Aka RAT TAPEWORM
• Hymenolepis diminuta egg morphology:

  55-85 um

  3 pairs hooklets

  polar thickenings present

  polar filaments absent

  embryophore present n colorless
• Hymenolepis diminuta adult morphology:

  4 suckers

  present rostellum

  absent hooks

  twice wide as long

  sacklike uterus filled with eggs
• Hymenolepiasis present mild symptoms such as diarrhea,

  nausea, abdominal pains, and anorexia.
• Praziquantel treatment of choice against H. diminuta
• Niclosamide

  • is an effective alternative therapy; however, it is not yet readily available in the United States
• HYMENOLEPIS NANA aka DWARF TAPEWORM
• Hymenolepis nana

  • is considered to be the most common tapeworm recovered in the United States, particularly in the southeastern part of the country.
  • Present in tropical and subtropical climates worldwide.
  • From contaminated human feces to contaminated rodents as a source of infection.
• Hymenolepiasis

  • develop gastrointestinal symptoms, such as abdominal pain, anorexia, diarrhea, dizziness, and headache
• Praziquantel

  • treatment of choice for infections with H. nana
• Niclosamide

  • effective alternative medication; however, it is not yet readily available in the United States For H. Nana
• Hymenolepis nana egg morphology:

  45by38um

  3pairs hooklets

  present polar thickenings and filaments

  colorless
• Hymenolepis nana adult morphology:

  4suckers

  rostellum short

  hooks one row

  twice as wide as long
• DIPYLIDIUM CANINUM aka dog or cat tapeworm, pumpkin seed tapeworm
• Dipylidium caninum egg morphology:

  30-60um

  6-hooked oncosphere
• Dipylidium caninum adult morphology:

  4suckers

  club shaped

  absent hooks

  pumpkin seed shape

  full of eggs in enclosed embryonic membrane
• Praziquantel

  • is the treatment of choice for infections with D. caninum
• Niclosamide and Paromomycin

  • proven effective alternative treatments for D. Caninum
• DIPHYLLOBOTHRIUM LATUM Aka fish tapeworm
• D. latum

  • varies from the four cuplike suckers present on the other cestode species.
  • almond-shaped and contains two long, prominent, sucking grooves
• Diphyllobrothrium latum egg morphology:

  55-75um long

  oblong

  undeveloped

  smooth;yello-brown in color
• Diphyllobrothrium latum adult morphology:

  two sucking grooves

  almond

  wider than long

  central location of uterine structure
• Diphyllobothriasis

  • fish tapeworm infection, broad fish tapeworm infection
  • Symptoms consistent with digestive discomfort
  • Overall weakness, weight loss, and abdominal pain
• Praziquantel & Niclosamide

  • Are the drugs of choice for the treatment of D. latum infections