Immunodiagnosis of Human Trichinosis Using Counterelectrophoresis and Agar Gel Diffusion Techniques *

Abstract

A rapid, accurate immunodiagnostic test for trichinosis has been developed. The test employs particle-associated antigens derived from cell-free homogenates of muscle larvae of Trichinella spiralis in the technique of counterelectrophoresis (CE). A supplementary test using agar gel diffusion (AGD) serves to confirm results obtained by CE. Using these two tests, we showed that 4% (8/189) of normal human sera were positive by CE, and 3% (10/334) of normal human sera were positive by AGD. Both of these values are well within the 5% incidence range of human trichinosis in the United States. Moreover, 90% (94/104) of Trichinella sera which were positive by the bentonite flocculation test were also positive by both the AGD and CE tests. Sera from patients with parasitic infections other than trichinosis were tested for the presence of cross-reacting antibodies. Included in this group were sera from patients with amebiasis, echinococcosis, filariasis, and schistosomiasis. Among these sera some gave false positive tests when first tested by AGD, but few gave false positives when tested further by CE.