Pathogenicity in Pigs Experimentally Infected with Eimeria spinosa

Abstract

N. americanus in the intestines of YAH. The worm burden in YAH receiving 500 ExNaL3 subcutaneously along with short-term HCA treatment was distinctly higher (22-fold) than other groups (Table I). It would therefore be interesting to see how long N. americanus survive in the intestines of YAH and how they compare with that of baby hamsters. Thus, an experiment was conducted in which YAH received 500 ExNaL3 subcutaneously, followed by HCA treatment on days 5, 6, and 7 after infection. At the same time, baby hamsters were infected with 100 EnNaL3 percutaneously. These experimental protocols enabled both baby, as well as YAH, to carry N. americanus in their intestines. Worm burdens were compared during 4, 6, 8, and 11 wk after infection. There was no significant difference in the worm burdens between baby and young adult hamsters, and N. americanus survived well until examination at 11 wk (Fig. 1). This clearly showed that the experimental modifications adopted rendered YAH suitable for maintaining the enteric phase of N. americanus infection. This new method of infecting young adult hamsters will facilitate the study of hookworm immunology by allowing preinfection handling of experimental hosts. This paper is contribution No. 812 from Hindustan Ciba-Geigy Research Centre. Thanks are extended to Dr. Sheila Talwalker of this research centre for statistical analysis.