A Comparison of Three Strains of Trichinella Spiralis

Abstract

Summary and Conclusions 1. It has been emphasized that accurate techniques are essential for proper quantitative investigation in the field of experimental trichinosis. 2. There appeared to be little or no difference among the three strains of T. spiralis studied in regard to lethal dose, survival time of animals and extent of parasitization of the musculature. 3. As criteria for proper investigation of a problem in experimental trichinosis, lethal dose and survival time of animals possess many limitations. It was almost impossible to predict the survival time of mice infected with T. spiralis unless massive doses of larvae were given. No animals died during the 60 day period when infected with less than 30 larvae per gram of body weight. All but 2 animals died when infected with doses greater than 60 larvae per gram of body weight. Many animals infected with 40 larvae per gram of body weight survived the 60 day period after infection. 4. Considerable variations in the proportions of larvae recovered to larvae fed were encountered in all larval dose groups but the average size of the proportions in each group indicated that the size of larval dose had little influence on their trend.