Immunocytochemical demonstration of Chlamydia infection in the urogenital tracts.

The peroxidase-antiperoxidase (PAP) technique was applied in cellular samples for the detection of chlamydial infection. Urethral scrapings were obtained from 316 males with clinically suspected urethritis. Positive PAP staining was detected in 118 (37%) of 316 tested. Cellular samples from the endocervix of 25 (54%) of 46 female contacts of males with positive Chlamydia-infected cells had positive Chlamydia-PAP staining. Chlamydia was also found in 12 (25%) of 48 male with gonorrhea. Serum IgG antibodies against Chlamydia trachomatis were evaluated using an enzyme-linked immunosorbent assay. A total of 29 out of 73 patients had positive Chlamydia serology; of these, 21 were positive for PAP staining, and eight were negative. The determination of Chlamydia antigen by means of the PAP technique appears to be a satisfactory method for detecting Chlamydia in male and female genital specimens; also, the procedure can be done readily in most laboratory settings.