Comparison of single and trickle infections of pigs with eggs of the Asian Taenia.

Two groups of seven Belgian Landrace piglets each were either infected with a single dose of 3000 or with five consecutive doses of 600 Asian Taenia eggs at weekly intervals. Nine weeks after the first infection all pigs were autopsied and the number of metacestodes was obtained by slicing the liver. There were no significant differences between the mean number of viable or dead cysts present in both groups of animals. Only very low numbers of living metacestodes were found: 0.4% (3/779) of the total number of cysts present in the single infection group and 1.8% (13/707) in the trickle infection group. Circulating antigens could be detected in only four out of 13 animals and no differences in antibody kinetics were present between the two groups of pigs. The presence of high numbers of degenerated cysts in experimental as well as in field conditions seems to indicate that the biotic potential of the Asian Taenia is rather low.