Angiostrongyliasis Costaricensis

Key Features

• Angiostrongylus costaricensis causes gastrointestinal inflammation

• Human infection follows ingestion of larvae within slugs or snails or on material contaminated by these organisms

• Since the parasites are not in their natural hosts, they cannot complete their life cycles

• However, they can cause disease after migrating to the brain or gastrointestinal tract

Clinical Findings

• Parasites penetrate ileocecal vasculature and develop into adults, which lay eggs, but do not complete their life cycle

• Disease is due to an inflammatory response to dying worms in the intestinal tract, with an eosinophilic granulomatous response, at times including vasculitis and ischemic necrosis

• Common findings mimic appendicitis and include

  • Abdominal pain (commonly localized to right lower quadrant)

  • Vomiting

  • Fever

  • A mass may be appreciated

• Symptoms may recur over months

• Uncommon findings

  • Intestinal perforation or obstruction

  • Disease due to migration of worms to other sites

Diagnosis

• Biopsy of inflamed intestinal tissue may show worms localized to mesenteric arteries and eosinophilic granulomas

Treatment

• Many cases managed surgically, usually for suspected appendicitis

• It is not known if antihelminthic therapy is helpful