[The infection rate of Chlamydia trachomatis in young adult men without urogenital symptoms--screening test using urine sediments].

: The detection of C. trachomatis antigen in first-voided urine sediments has recently been achieved by means of IDEIA CHLAMYDIA (IDEIA, Novo Nordisk), an EIA kit using monoclonal antibodies. Therefore, this kit was used as a screening test to examine the infection rate of C. trachomatis in young adult men without symptoms. The titers of serum IgA and IgG antibodies to C. trachomatis were also determined. 1. Antigen detection from first-voided urine sediments of young adult men without urogenital symptoms (141 cases): The detection rate by IDEIA was 5.0% (7/141). Three of the 7 cases which were positive for antigen in first-voided urine sediments were reaffirmed as having asymptomatic C. trachomatis urethritis, since they were also revealed to have C. trachomatis in the urethra. 2. The positive rates of serum antibodies: The titers of serum antibody were determined in 128 cases out of the 141 cases. The positive rates of IgA and IgG were 6.3% (8/128) and 35.9% (46/128) respectively. The positive rates of IgA and IgG antibodies were significantly higher in cases with positive antigen in first-voided urine sediments than in those which were negative. These results indicate that this kit is useful for antigen detection. 3. The screening test revealed asymptomatic C. trachomatis infections in 5% of young adult men, suggesting the extensive spread of the infection. The screening test using first-voided urine sediments will be useful in public health.