Migrating juveniles damage blood vessels causing localized edema. They may also cause pneumonia, pleurisy, encephalitis, meningitis, nephritis, deafness, peritonitis, and brain or eye damage. Death may occur from myocarditis. Ten days after infection the juveniles will have penetrated the muscle fibers. This causes muscular pain, difficulty breathing or swallowing, swelling of masseter muscles, weakening of pulse and blood pressure, heart damage, nerve disorders and hallucinations.
Death is caused by heart failure or respiratory or kidney malfunction.
A muscle biopsy test is most accurate but is hardly ever used. Digestion of the muscle in gastric enzymes will reveal the parasites. There are also immunodiagnostic tests in use. There are no satisfactory treatments. Doctors mainly try to relieve the symptoms with analgesics and corticosteroids.