Tapeworm Infection, Beef

Essentials of Diagnosis

• Generally asymptomatic

• Abdominal pain and other gastrointestinal symptoms may be present

• Eosinophilia common

General Considerations

• Six tapeworms infect humans frequently

• The large tapeworms are

  • Taenia saginata (the beef tapeworm, up to 25 m in length)

  • Taenia solium (the pork tapeworm, 7 m)

  • Diphyllobothrium latum (the fish tapeworm, 10 m)

• The small tapeworms are

  • Hymenolepis nana (the dwarf tapeworm, 25–40 mm)

  • Hymenolepis diminuta (the rodent tapeworm, 20–60 cm)

  • Dipylidium caninum (the dog tapeworm, 10–70 cm)

• Humans are the only definitive host of T saginata and T solium

• Humans are infected by eating raw or undercooked infected beef

• An adult tapeworm consists of a head (scolex), a neck, and a chain of individual segments (proglottids) in which eggs form in mature segments

Demographics

• Infection most common in cattle breeding area

• Gravid segments of T saginata are passed in human feces to soil, where they are ingested by grazing animals, especially cattle

• The eggs then hatch to release embryos that encyst in muscle as cysticerci

Symptoms and Signs

• Most infected persons are asymptomatic

• Abdominal pain and other gastrointestinal symptoms may be present

Differential Diagnosis

• Pork, fish, dwarf, rodent, or dog tapeworms

• Chronic fatigue syndrome

• Chronic hepatitis

• Irritable bowel syndrome

• Amebiasis

• Ascariasis

• Enterobiasis (pinworm, mostly children)

• Hookworm disease

• Strongyloidiasis

• Celiac disease or tropical sprue

• Pernicious anemia (D latum)

Laboratory Tests

• Complete blood count; eosinophilia is common

Diagnostic Procedures

• Infection is often discovered by finding passage of proglottids in stool

Medications

• Praziquantel

  • Treatment of choice

  • Single dose of 5–10 mg/kg orally is highly effective

  • Side effects include headache, malaise, dizziness, abdominal pain, nausea

• Niclosamide

  • Alternative therapy

  • Single dose (2 g for adults, chewed) is effective

  • Side effects include nausea, malaise, abdominal pain

Prognosis

• Excellent with therapy

When to Refer

• For assistance in making the diagnosis

• Inability to clear the infection

Prevention

• Cysticercus bovis is killed by cooking at 56°C or freezing at –10°C for 5 days

• Pickling is not adequate