Tapeworm Infection

Tapeworm infection, also called taeniasis or cestodiasis, is a parasitic infestation by Taenia saginata (beef tapeworm), Taenia solium (pork tapeworm), Diphyllobothrium latum (fish tapeworm), or Hymenolepis nana (dwarf tapeworm). Tapeworm is usually a chronic, benign intestinal infection; however, infection with T. solium, also called cysticercosis, may cause dangerous systemic and central nervous system symptoms if larvae invade the brain, eyes, or striated muscle of vital organs. A single tapeworm can produce 50,000 eggs in a single day and may live for 25 years. The incidence of tapeworm infection is higher in countries with poor public hygiene.

Causes

T. saginata, T. solium, and D. latum are transmitted to humans through ingestion of beef, pork, or fish, respectively, that contains tapeworm cysts. Gastric acids break down these cysts in the stomach, allowing them to mature. Mature tapeworms attach to the intestinal wall and produce ova that are passed in the feces. H. nana, naturally found in beetles and mice, can be transmitted directly from person to person and thus requires no intermediate host. H. nana completes its life cycle in the intestine. (See Common tapeworm infections.)

Complications

Severe tapeworm infection can lead to dehydration and malnutrition. Intestinal obstruction, obstructed bile or pancreatic ducts, and appendicitis may also occur. Central nervous system complications, such as hydrocephalus, seizures, and stroke, may result from infection with T. solium. Some cases may be fatal.

Assessment Findings

Signs and symptoms vary with the type of infection. Symptoms may be absent or mild, such as nausea, flatulence, hunger, weight loss, diarrhea, and increased appetite. Occasionally, worm segments may exit through the anus and appear on bed clothes. A patient with beef tapeworm may complain of a crawling sensation in the perianal area; and pork tapeworms may cause seizures, headaches, and personality changes. Neurologic symptoms may include hemiparesis and sensory disturbances. If cysticercosis affects the eyes, intraocular larvae may be seen.

Diagnostic Tests

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