Chlamydia trachomatis infection in the semen of asymptomatic infertile men: detection of the antigen by in situ hybridization.

The prevalence of Chlamydia trachomatis and other microbes was studied in 94 semen samples from asymptomatic infertile males. Simultaneously, we sought evidence for inflammation of the genital tract by determining the polymorphonuclear granulocyte (PMN)-elastase concentration in the seminal plasma. The C. trachomatis genome was detected in 8 cases using in situ hybridization. The antigen, however, was undetectable by enzyme-linked assay (Chlamydiazyme) in the same samples. Ureaplasma urealyticum was isolated from 16 cases. The PMN-elastase concentration in the semen positive for the C. trachomatis genome was significantly higher than in C. trachomatis-negative and U. urealyticum-positive cases, but no significant difference was observed between C. trachomatis-negative and U. urealyticum-positive cases. C. trachomatis trachomatis in situ hybridization-positive cases correlated well with C. trachomatis-specific IgA antibody positivity and a PMN-elastase concentration over 250 ng/ml. These findings suggest that in situ hybridization is a reliable method for the detection of C. trachomatis infection and that the presence of C. trachomatis, but not U. urealyticum, in the male genital tract correlated well with evidence of inflammation.