Evaluation of techniques for the recovery of live intestinal Trichinella spiralis worms from experimentally infected foxes.

Previously described methods for the recovery of intestinal Trichinella worms from rodents are not feasible when applied in larger experimental animals such as foxes. In this study,worm recovery by standard technique of simple incubation of the intestine in saline was compared to embedment of the intestine in an agar gel. The small intestines of Trichinella spiralis infected foxes (4-5 days post inoculation) were slit lengthwise and the two corresponding halves were processed with one of the two incubation methods. Worms were recovered from all samples, and the total worm recovery ranged from 0.2-4.4% of the infection dose. The samples from the standard incubation were very unclear and time consuming to count compared with samples from the agar gel embedment,in which the intestinal debris were kept inside the agar. As the agar gel technique generally yielded higher numbers of worms than the corresponding standard incubation sample, it is with some optimisation, recommended for recovery of intestinal Trichinella worms from foxes.