Detection of a circulating parasitic antigen in acute infections with Trichinella spiralis: diagnostic significance of findings.

Circulating parasitic antigen was demonstrated in the sera of rats and patients infected with Trichinella spiralis. Using a dot-immunobinding method, the antigen was detected in the sera of experimental animals from the fourth day of infection and in more than one third of the patients by the end of the third week from infection. The method proved to be simple, sensitive and specific. It should assist an early diagnosis of trichinellosis demonstrating the antigen in some cases with negative or doubtful results for specific antibodies.