Seminal tract infections: impact on male fertility and treatment options

Bacterial and viral infections of the genital tract may be important aetiological factors for male infertility. Infectious processes may lead to deterioration of spermatogenesis, impairment of sperm function and/or obstruction of the seminal tract. Detection of bacteria in semen does not necessarily signify infection since bacteriospermia may represent contamination, colonization or infection. Reported prevalence of Ureaplasma urealyticum in human semen varies from 10 to 40%. Enterobacteria can even be found in up to 90% of semen samples depending on the sensitivity of detection methods used. Chlamydia trachomatis is the most frequent sexually transmitted bacterial organism in industrialized countries. It is suggested that its main influence is due to sexual transmission resulting in tubal disease and subsequent infertility in the female partner rather than a direct influence on male reproductive functions. The effect of leukocytospermia on male fertility is controversial. This is probably due to different detection methods, different populations studied and to the fact that leukocyte subtypes in semen may have different functions. In addition to potentially negative effects, leukocytes may even have protective effects on spermatozoa. Only recently have amplification methods been established to detect viruses in semen with high sensitivity and specificity. It is unclear if these infections significantly contribute to male infertility.