ABSTRACT
Angiostrongylus is a member of the family Metastrongylidae that contains species that inhabit either the pulmonary (bronchi) parenchyma and blood vessels or mesenteric arteries of their rat hosts.
Adult A. cantonensis lives in the pulmonary arteries and right heart of the rodent host, where the female lays thin-shelled, unembryonated eggs into the blood stream which become entrapped in the capillaries of the lung, where they mature into first-stage larvae. They then break out of the egg and migrate via the respiratory tree (bronchioles) to the epiglottis, esophagus and into the intestine, from where they are excreted in feces. In the soil, the first-stage larvae are then ingested by an intermediate host (snail, slug) in which the larva develops into the infective third-stage larva. On ingestion by a rodent (or human) the larvae penetrate the vasculature of the intestinal tract and migrate to the central nervous system (brain) where they mature and migrate to the meninges. In the rodent the larvae enter the external jugular vein and migrate to the heart and ultimately the pulmonary arteries, where they develop into male
and female adult worms (17-25 mm long), repeating the cycle.
