Gnathostomiasis

Key Features

• Infection caused by eating undercooked fish, shellfish, chicken, pork

• Can also be transmitted by ingesting copepods in contaminated water

• After ingestion, larvae cannot complete development in humans, but rather migrate through tissues

• Infection is most common in southeast Asia but has been described in many other areas

Clinical Findings

• Acute gastrointestinal symptoms

  • Include nausea, vomiting, abdominal pain, and fever

  • May develop soon after infection and persist for 2–3 weeks

• The disease may then progress to findings consistent with cutaneous or visceral larva migrans

• Migratory subcutaneous erythematous swellings may be painful or pruritic

• Migrating larvae may also invade other tissues, leading to findings in the eyes, lungs, intestines, and elsewhere

• Most serious complications are due to invasion of the CNS, leading to eosinophilic meningoencephalitis and other serious findings

• Severe pain due to migration through spinal roots and focal neurologic findings may be seen

• CSF eosinophilic pleocytosis and peripheral eosinophilia are seen

Diagnosis

• Diagnosis is suggested by history of intermittent subcutaneous swellings and typical CNS findings

• Worms can occasionally be identified in skin lesions

• Serologic tests may be helpful

Treatment

• Ivermectin, 200 mcg/kg single oral dose, or albendazole, 400 mg/kg orally daily for 21 days

• However, indications for treatment are uncertain with CNS disease because inflammatory responses to dying worms might worsen outcomes; corticosteroids may be indicated with antihelminthics in these cases