Population dynamics of Angiostrongylus cantonensis during primary infections in rats.

About 35% of Angiostrongylus cantonensis larvae became patent adults irrespective of the dose used to establish primary infections in laboratory rats. Worm growth and fecundity was depressed in infections from high compared with low doses of infective larvae. Rats infected with up to 50 A. cantonensis larvae survived infection better than rats given greater numbers of larvae. The biology of A. cantonensis surviving in laboratory rats from single infections with 50 larvae for over a year was studied. Stable worm numbers and fecundity were established 90 days after infection but the worms continued to grow until the experiment was terminated.