Prevalence of Chlamydia trachomatis in cases of genital non-gonococcal infection according to microbiological and serological investigations.

An investigation on the prevalence of Chlamydia trachomatis was carried out on 231 patients (115 men and 116 women, mean age 31.6 years) with genital non-gonococcal infection in order to study the role of this microorganism in infertility and/or sterility in the Italian population. One hundred and sixty-six apparently healthy subjects (108 men and 50 women, mean age 32.4) were also included as control for serological comparison only. Persons with gonococcal infection were excluded. ELISA method was chosen for the direct C. trachomatis examination of "scraping" samples. Serological investigations were carried out by means of the indirect immunofluorescence test for IgM and IgG determination as well as the immunoperoxidase assay for IgA antibodies. A direct C. trachomatis positive test was demonstrated in 27.8% of men vs. 11.2% in women (p less than 0.01) in the patient group. Anti-C. trachomatis IgG specific antibodies were present respectively at any serum dilution in 50.2% of patients vs. 47.6% of normal subjects respectively (p greater than 0.5). The low presence of C. trachomatis (19.5%) at the direct test contrasts with the higher percentage of anti-C. trachomatis positive patients (50.2%) in the same group suggesting that serological tests may be more useful than the direct test in demonstrating an active C. trachomatis infection provided that IgM, IgG and IgA specific antibodies be contemporaneously investigated.