Observations on the early migration of the larvae of Ascaris suum Goeze, 1782 in white mice

Abstract

The early (0–18 h) migration of the larva of Ascaris suum in the white mouse was studied.The eggs hatched in all gut regions posterior to the stomach, the time of maximal release being between 4 and 8 h after infection. The caecum was the site of maximum larval penetration.Penetrating second-stage larvae produced demonstrable spreading factor reaction with Evan's Blue in the mucosa of the gut. Larvae were located in the venules and lymphatics of the caecum wall as well as in the ileo-colic and hepatic portal veins. Larvae were found in the liver after 9 h and in the lungs 12 h after infection. Larvae were not seen in the muscula externa of the gut and eggs were not found in any region of the body other than the gut lumen.A similar pattern of larval distribution was seen in the gut wall of the rat and the guinea-pig.I am greatly indebted to Dr D. A. Erasmus for his encouragement, advice and supervision during this investigation, and also for carrying out the experimental infections. I also wish to thank Professor J. Brough for the provision of excellent laboratory facilities. Many thanks are due to Mr J. H. M. Hughes (Veterinary Officer) and the meat inspectors at Roath Abattoir who provided me with infected material. I wish to acknowledge the financial support of the Pig Industry Development Authority and the Agricultural Research Council.