Differentiation of Trichinella spiralis spiralis and Trichinella spiralis nativa based on resistance to low temperature refrigeration.

A refrigeration technique to differentiate the subspecies, Trichinella spiralis spiralis and T. spiralis nativa is described. Trichinella spiralis spiralis trichinae in musculature do not survive 48 hours post-refrigeration at -32 degrees C while T. spiralis nativa will survive 72 hours and longer at the same temperature.