Trichomonas infections can cause infections in both men and women. In men this infection can cause inflammation and irritation of the urethra, or urine canal. Typical STD screening using either a swab or urine based testing looks for the presence of gonorrhea or chlamydia. Your partner may not have been screened for trichomonas. A repeat urinanalysis with culture can reveal if he or any other sexual partners may have been exposed to this infection. Trichomonas is sexually transmissible, and as such is considered a sexually transmissible infection. It is important for both partners to use barrier methods (condoms) to reduce the change of transmission or infection until both partners have been screened or treated for any sexually transmitted infection.
For more information about trichomonas infections, please see the CDC website at:
http://www.cdc.gov/std/trichomonas/STDFact-Trichomoniasis.htm