Objective: To compare endourethral swab and urine collection as diagnostic specimens for the detection of urethral gonorrhea using the polymerase chain reaction (real-time PCR with TaqMan probes).

Materials and Methods: Endourethral swabs and urine specimens were collected from 268 men who have sex with men [MSM] attending two walk-in clinics, a sexually transmitted diseases mobile clinic [STDs mobile clinic] and an antiretroviral clinic [ARV clinic]. The two specimens were processed for Neisseria gonorrhea [NG] DNA detection using real-time PCR with TaqMan probes. The main outcome was a positive result of gonorrhea from either sample.

Results: The 268 MSM had urine collections, but only 267 had taken endourethral swabs for PCR. NG DNA was detected in 104 (38.9%) of the 267 participants. The detection of NG indicated by a positive result from urethral swab was 73 (27.3%, 95% CI 22.1 to 33.1) with negative results in 194 men (72.6%). The detection of NG with a positive result from urine specimens was 54 (20.2%, 95% CI 15.9 to 25.9) with a negative result in 213 men (79.4%). In 23 of the 267 participants (8.6%), both specimens were positive (agreement 69.66%, kappa 0.169). In addition, discrepancies were found in 80 of the 267 (29.9%) subjects, in which only one of the genital specimens had positive results.

Conclusion: The high discrepancy between positive results of gonorrhea between urethral swab and urine collection suggests that both of specimens should be combined for the highest detection rate of urethral gonorrhea in male population.

Keywords: Endourethral swab, Urine collection, Urethral gonorrhea, Men who have sex with men