Taenia saginata

• Beef tapeworm


  Common name
• Adult


  • Measures 5 – 10 meters on the average, although under favorable conditions, may attain a length of 25 meters or more
  • Has more segments than T. solium, numbering from 1,000 – 2,000 segments
  • Scolex measures 2 mm, quadrate in shape and bears 4 prominent suckers but differs from T. solium in the absence of a well-developed rostellum and hooks
  • Mature segments are somewhat broad, have irregularly alternate genital pores and differ from T. solium in having as many testes numbering 330 – 400 follicles and in lacking the accessory ovarian lobe
  • In gravid proglottid, the testes and ovary have atrophied, and the uterus has 15 – 20 or more lateral uterine branches (average 18)
  • Each proglottid may contain 97,000 to 124,000 eggs
• The eggs cannot be distinguished from those of T. solium or from those of Multiceps and Echinococcus
• Life cycle of T. saginata

  1. Cattle ingest mature egg

  2. Oncosphere is liberated, penetrates through the intestinal wall, reaches the lymphatics or mesenteric venules and is carried through the circulation

  3. Oncosphere is filtered out in the striated muscles, particularly the pterygoid muscles, those of the tenderloin region and the myocardium, where in 60 – 75 days develops into cysticercus bovis

  4. Cysticercus larvae may remain viable in the tissues of cattle for about 8 months

  5. On ingesting raw or inadequately cooked infected beef, man, the sole definitive host, becomes infected, with a prepatent period of 10 –12 weeks
• The life cycle of T. saginata is similar to that of T. solium except for the intermediate host
• Intermediate hosts

  • Cattle
  • Camels
  • Goats
  • Carabaos
• Cattle are the most important intermediate host
• T. saginata

  • Ordinarily well tolerated, in spite of its large size
  • May produce acute intestinal obstruction
  • Toward the end of the prepatent period, diarrhea and hunger pains frequently develop and loss of weight may occur
  • The most common symptoms are discomfort and embarrassment occasioned by the crawling of the proglottids from the anus, with a strong tendency to crawl during the day when the host is active
• Diagnosis of T. saginata infection

  1. Recovery of eggs or proglottids from the feces

  2. Study of the uterine branches in the gravid proglottids provides a differential and specific diagnosis
• Treatment


  The drug of choice is praziquantel
• Prevention and control: Education regarding cooking of beef and control of the disposal of human feces are critical measures