Detection of circulating Trichinella spiralis larvae by polymerase chain reaction.

Several investigators have successfully applied the polymerase chain reaction to the amplification of DNA from Trichinella spiralis muscle-stage larvae. We show herein that specific DNA can be amplified from T. spiralis migratory larvae in the blood of experimentally infected mice. The polymerase chain reaction detected the presence of migratory larvae in mouse blood from day 5 to day 14 of infection. The technique may be applied to human trichinosis, but its diagnostic value will depend on the severity and stage of the infection.