Microscopic and microbiological findings for evaluation of chronic prostatitis.

OBJECTIVE: The aim of this study was to assess the significance of different diagnostic methods for detecting prostatic inflammation/infection.

MATERIALS AND METHODS: A group of 233 with symptoms suggesting prostatitis without urethral discharge attending an outpatient Prostatitis Clinic was considered. All were evaluated by the same urologist according to a protocol comprising medical history, physical and transrectal ultrasound examination. Patients had a urethral swab for bacterial culture and additional swabs for identification of C. trachomatis, T. vaginalis, U. urealyticum, M. hominis and Candida spp. Patients also underwent a four-specimen study according to Meares and Stamey (first voided urine VB1, midstream urine VB2, expressed prostatic secretion EPS and urine after prostatic massage VB3) and culture of the seminal fluid.

RESULTS: Of 233 patients evaluated, 47% had a positive urethral culture, 35% a positive culture of the seminal fluid and only 13% a positive culture of one or more samples of the four-specimen localization test. A positive culture of VB1 or VB2 was very rarely associated with a negative swab culture respectively in 1% and 0.9%; on the contrary, a positive swab culture was frequently associated with negative VB1 and VB2 culture respectively in 90% and 91%. Of the patients with positive urethral culture only 8% and 2% had more than 10 leukocytes respectively in VB1 and VB2. A positive seminal culture was associated with negative EPS and VB3 culture respectively in 89% and 83% cases; on the contrary, a positive culture of EPS or VB3 was associated with a negative seminal fluid culture respectively in 67% and 27% cases. In 49% patients with positive culture of the seminal fluid, more than 10 leukocytes in VB3 were observed. Only in 9 of the 47 patients with positive culture of the seminal fluid EPS can be obtained and 3 of them (33%) had more than 10 leukocytes in EPS.

CONCLUSIONS: Culture and determination of leukocytes in first voided and midstream urine showed a low sensitivity in detection of urethral infection/inflammation compared to urethral swab culture. On the contrary, microscopic examination of urine after prostatic massage was confirmed as a useful indirect indicator in the diagnosis of prostatic inflammation and showed to be more feasible compared with the analysis of expressed prostatic secretion. In conclusion, urethral swab culture and post-massage urine culture and microscopic examination could be proposed as an alternative standard protocol in order to simplify the evaluation of prostatitis-like syndrome in the clinical practice.