was first described in 1971. Human infections are most common in Costa Rica but have been reported in Mexico, Central and South America.Life Cycle
The life cycle is similar to A. cantonensis, with the human being an accidental host by consumption of snails and salad vegetables. Unlike A. cantonensis, the larvae of A. costaricensus
penetrates the
intestinal wall and rersults in inflammatory lesions of the bowel wall. Here the life cycle ends.
Morphology
The eggs are 90m, oval, thin shelled and
can be embryonated. The adult female measures 42 x 300mm and the males measure 22 x 140mm.
Clinical Disease
The most common symptoms are pain and tenderness with fever, vomiting
and diarrhoea. A tumour-like mass is often palpable and can mimic malignancy. Often the appendix is involved but the worms can also be found in the regional lymph nodes and mesenteric arteries. They
can also be found in the spermatic arteries causing testicular obstruction and necrosis. Occasionally the larvae and the ova reach the liver and symptoms may mimic visceral larvae migrans. Eosinophilia is also
present.
