Tests and diagnosis

By Mayo Clinic Staff

Trichinella larvae bury themselves inside muscle tissue rather than remain in the intestine as in other roundworm infections, so stool sample tests don't often show evidence of the parasite. The initial diagnosis relies on the classic signs and symptoms — swelling around the eyes, muscle inflammation and fever. To confirm the diagnosis, your doctor may use these tests:

  • Blood tests. Your doctor may take a blood sample and test it for signs suggesting possible trichinosis — an increase in the number of a certain type of white blood cell (eosinophils) or the formation of antibodies against the parasite after several weeks.
  • Muscle biopsy. While the blood test typically is enough to establish a diagnosis, your doctor may also recommend a muscle biopsy. A very small piece of muscle is removed and examined under a microscope to look for trichinella larvae.
May. 24, 2012