Cysticercosis (larval Taenia solium infection) and Taeniasis (Adult Taenia Spp. Infection)

Cysticercosis is a disease caused by the larval stage of the pork tapeworm (Taenia solium). Infection is contracted when humans accidentally consume food contaminated with embryonated eggs of Taenia solium. Ingested larvae then disseminate throughout the body and form cysts within tissue (mostly commonly subcutaneous tissue, the central nervous system and ocular tissue).

Disease is a result of the presence of these cysts and the associated inflammation in tissue. Neurocysticercosis is the most severe form of the disease and may present with unexplained seizures, confusion or focal neurological deficit.

Taeniaisis, caused by the presence of the adult stage of either the beef tapeworm (Taenia saginata) or the pork tapeworm (Taenia solium) within the human gastrointestinal tract. Disease is contracted via ingestion of meat (beef or pork respectively) containing cysticerci. These larvae then mature in the human gut. Infection is often asymptomatic, but patients may experience non-specific gastrointestinal upset and may also visualise segments (proglottids) of the adult worm in their stool.

Detection of Taenia spp. ova and segments by microscopy

• Sample type: Standard stool sample/tapeworm segment(s) must NOT be in any fixative. If sending segments for identification (see also Human helminthiasis for identification of worms)
  
  HIGH RISK stickers must be used if Taenia solium is suspected.

Microscopy of stools for ova is recommended in these cases but cannot differentiate to species level.

Detection of antibodies to Taenia solium by serology

• Sample type: A minimum of 0.5ml of serum is required, CSF testing is also available (please inform laboratory before hand and provide as much CSF as you are able to spare). Samples can be transported at room temperature.

A serological service (EITB Immunoblotting) is provided. Intestinal infections with Taenia solium or saginata (taeniasis) do not usually result in positive Taenia serology.

Detection of Taenia solium antigen

• Sample type: A minimum of 0.5ml of serum is required, CSF testing is also available, please provide as much CSF as you are able to spare (minimum volume for the test is 0.2ml).

For individuals with a high suspicion/confirmed infection with Taenia solium, detection of circulating cysticercal antigens is also available. This test detects the presence of antigens secreted by live cysticerci within the patient.