Simplified microimmunofluorescence test with trachoma-lymphogranuloma venereum (Chlamydia trachomatis) antigens for use as a screening test for antibody.

A simplified microimmunofluorescence test with trachoma-lymphogranuloma venereum (Chlamydia trachomatis) antigens has been devised as a screening test for antibody in human sera. The test differs from our standard procedure by amalgamating 15 different immunotypes into nine antigen pools, by using only three serum dilutions, and by dropping use of duplicate slides. The screening test could be performed on at least six times as many sera as the standard test for a given unit of effort. It was shown to have a sensitivity equal to the standard test and an ability to determine specific immunotype on the basis of antibody pattern (72%) only slightly reduced from the standard test (84%). The screening test was carried out on 876 patients from different population groups in the Seattle area. The tests showed that antibody was present frequently in persons attending venereal disease clinics (60%) and commonly (25%) in a group of adults without venereal disease. Nine percent of children under 15 years of age tested had antibody; the significance of this finding is unknown.