Development of patent Ascaris suum infections in pigs following intravenous administration of larvae hatched in vitro
The normal tissue migration of Ascaris suum in the pig host involves larval development in the liver accompanied by considerable pathological changes. The vast majority of larvae that reach the small intestine are later expelled by unknown mechanisms. We show that when migration through the liver is bypassed by inoculation of pigs with an intravenous dose of larvae hatched in vitro, the larvae not only complete migration and return to the small intestine, but they also seem to have a greater chance of survival to adulthood. This technique offers new possibilities for studies on specific lung involvement in protective immunity, provides valuable information for the understanding of self cure by larval expulsion, and adds to our understanding of the evolution of migration of Ascaris larvae in tissues.(Received February 20 1999)
(Revised May 27 1999)
(Accepted May 27 1999)
Key Words: Ascaris suum; intravenous inoculations; experimental infections; fixation of larvae.
c1 Corresponding author: Department of Clinical Studies, Large Animal Medicine, Royal Veterinary and Agricultural University, Bülowsvej 17, 1870 Frederiksberg C, Copenhagen, Denmark. Tel: +45 35 28 28 39. Fax: +45 35 28 28 38. E-mail: firstname.lastname@example.org