RESUMO
Different methodologies have been proposed to interpret the microbiological findings associated with contaminating, indigenous microbiota of the anterior urethra. In order to solve the controversy related to the diagnosis of chronic seminal infections in asymptomatic young adults, the results applying Stamey and Meares' criteria were compared with those obtained when semen cultures were studied for significant bacteriospermia. A total of 218 consecutive asymptomatic male partners of infertile couples were evaluated by the four-specimen technique described by Stamey and Meares' with the addition of semen (SM). Infection was detected in 46% by SM, while semen cultures (SC) showed a prevalence of infection of 41%; 73 patients were positive by both criteria and 102 negative; 27 patients were positive by SM technique in prostate fluid while their semen cultures were negative; 16 patients had positive semen cultures and were considered negative by SM. The kappa statistic indicated a good degree of agreement between both methodologies (kappa = 0.61, z = 8.68, p < 0.001). The estimated risk of being considered negative attributable to the semen culture (27 patients) was 25% (attributable risk = gamma ac- = 0.2550), and of being considered positive attributable to the semen culture (16 patients) was 26% (gamma ac+ = 0.2579). The 95% confidence limits were estimated in 12 to 39%, and in 13 to 31%, respectively. In view of these results, to establish the diagnosis of chronic prostatitis, the addition of prostatic fluid or voided urine cultures after prostatic massage, must be performed. Semen culture confronted with first-voided urine avoid overestimating seminal infection.