Larva Migrans of Baylisascaris potosis In Experimental Animals

Experimental Infection with Baylisascaris Potosis in Chickens

The larvae of the genus Baylisascaris can cause larva migrans in mammals and birds. This study investigated the larval migration of Baylisascaris potosis, the roundworm of kinkajou (Potos flavus), in chickens and the associated clinical manifestations of the host. Thirty-six 3-week-old chickens divided into 6 groups were orally inoculated with 3,000 B. potosis eggs/chick. Each group of chicken was necropsied at days 1, 2, 3, 7, 30 and 90 PI (post inoculation), and the number of larvae in various organs were counted until day 90 PI. No clinical signs were observed in chickens during the study. Larvae were detected from the liver, lungs or breast-muscles of 13/36 (36.1%) chickens. The mean total number of larvae in the liver, lungs and breast-muscles at days 1, 2, 3, 7, 30 and 90 PI were 0.34, 0.17, 1.66, 1.01, 0.17 and 0, respectively. No larvae were found in the brain, eyes, hid-limb muscles, heart, kidneys and spleen. Although infectivity of larvae in egg-inoculated chickens was low, the present study demonstrated that B. potosis larvae can migrate in chickens tissues up to day 30 PI. The result suggests that chickens can serve as a paratenic host for B. potosis and may underline a public health importance of B. potosis infection as a potential foodborne disease in humans.

Baylisascaris Potosis Larvae in Mice of Different Strains and Infectivity of Tissue Larvae

Migration of Baylisascaris potosis larvae in different mouse strains were compared, and infectivity of the persisting larvae in mice tissues were investigated. Five strains of mice, BALB/c, C57BL/6, AKR, B10.BR, and ICR were inoculated with 1,000 B. potosis eggs/mouse, and necropsied at week 13 post inoculation (PI). The other uninfected ICR mice (secondary host) were inoculated with 43 larvae/ mouse recovered from mice at week 13 PI with eggs, and necropsied at day 21 PI. Larvae in organs or tissues were counted at necropsy. One AKR mouse showed torticollis and circling at day 56 PI. At necropsy at week 13 PI, larvae were recovered from all mice. A mean total larvae recovered were 124.1 (n=40). Majority of larvae were found in the carcass (mean 113.9) and some in the viscera (mean 9.9). Zero to 1 larva were found in the brain or eyes of some mice. There were no differences among the mouse strains in the number of larvae, except in the viscera; more larvae were seen in BALB/c or ICR than in B10.BR mice. No larvae were found in the secondary host mice. Present study demonstrated that B. potosis larvae migrate well in the carcass of any strains of mice, however, the tissue larvae did not infect the secondary host. Results of our present study suggest that B. potosis larvae is less aggressive for the nervous tissue migration than that of B. procyonis larvae which is commonly known to migrate in central nervous system of mammals and birds.