The presence of germs in the semen, generally coming from the prostate, may lead to inflammatory processes which obstruct the seminal duct at any level. They may also adhere to the sperm, affecting their mobility or their fertilising capability. The microorganisms may favour the production of anti-sperm antibodies with a whole series of harmful effects which are detailed in the next section.
In the event of suspecting an infection of the seminal duct a culture from urine issued prior to ejaculation and semen should be undertaken. On occasion an expression of the prostatic gland through rectal manipulation may be indicated in order to ensure its secretions pass to the urethra, exiting directly from the meatus or they may be carried away by the urine. The prostatic secretion and post-prostatic massage urine are analysed to identify germs and other cells such as leucocytes (inflammatory cells). There may be disorders of the prostate or other components of the seminal duct which favour the infection and can be detected through an ultrasound scan.