Evaluation of the FIAX test for the detection of antibodies to herpes simplex virus and cytomegalovirus.

Laboratory Branch Complement Fixation and FIAX (fluorescence immunoassay) were compared for the detection of antibodies to herpes simplex virus and cytomegalovirus in human sera. Of 68 sera with no antibodies to herpes simplex virus by complement fixation, one specimen was positive by FIAX (specificity, 98.6%). Of 75 sera with complement fixation antibodies, five specimens were negative by the FIAX procedure (sensitivity, 93.8%). Comparable results were obtained with the cytomegalovirus antigen, in that only three of 76 sera with complement fixation antibodies gave positive FIAX results (specificity, 96.2%). Only three of 74 sera with complement fixation antibodies to cytomegalovirus were not detected by FIAX (sensitivity, 96.1%). FIAX titers increased with complement fixation levels in 39 of 42 serum pairs (93%) with herpes simplex virus antibody and in 44 of 47 sera (94%) containing antibodies to cytomegalovirus, but the increments were not necessarily linear. The FIAX test for measuring antibody to herpes simplex virus and cytomegalovirus antigens is specific, sensitive, rapid (three to four hours per 100 specimens), and reproducible.