Urine and the laboratory diagnosis of Chlamydia trachomatis in males.

OBJECTIVE

To determine whether the use of urine samples from male patients can replace urethral swabs for the rapid detection of Chlamydia trachomatis by the Pharmacia EIA.

SETTING

The STD clinic, Adelaide, South Australia.

PATIENTS

There were two separate groups of male patients. Group A (398) patients provided urethral specimens for the EIA and culture tests. The patients in Group B (356) provided an urethral swab and a urine sample for the EIA test.

METHODS

The urine samples and urethral swabs were tested for the presence of C trachomatis by the Pharmacia Chlamydia EIA. In addition, the urethral swabs from Group A patients were cultured for the organism by standard cell cultures. The infected cell cultures were identified by an immunofluorescence test using a FITC-monoclonal antibody to C trachomatis (Kallestad).

RESULTS

When the EIA was validated against culture, it showed a sensitivity of 100% and a specificity of 95% with the urethral swabs from Group A patients. The urine specimens were positive in 24% of those patients who yielded a positive EIA result in the urethral swabs.

CONCLUSIONS

Although the EIA test on urethral swabs showed high sensitivity and specificity when validated against culture, our results showed that the use of urine samples cannot replace urethral swabs for the laboratory diagnosis of this sexually transmitted disease.