Evaluation of indirect hemagglutination and its inhibition in the differentiation between antibodies to herpes simplex virus types 1 and 2 for seroepidemiologic studies: use of a II/I index threshold of 85 and an assay of type-specific antibodies.

Two parameters, a II/I index threshold value of 85 and an assay of type-specific antibodies to herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), were assessed, for seroepidemiologic purposes, for their efficacy in the establishment of past infections with HSV-1 and HSV-2 as indicated by the results of tests for indirect hemagglutination and its inhibition. Neither criterion alone established past infection with either HSV-1 or HSV-2. However, by combination of the two parameters, antibodies to HSV-1 and HSV-2 could be differentiated for seroepidemiologic studies.