Angiostrongyliasis Costaricensis

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

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

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

Many cases managed surgically, usually for suspected appendicitis

It is not known if antihelminthic therapy is helpful