Diagnosis of Trichomonas vaginalis infection in a male can be challenging.
The specimen to collect depends on the man's sexual practices:
(1) A male with trichomoniasis may present with a urethritis with discharge. Diagnosis during active infection tends to be easier since the number of organisms may be higher.
(2) A male who has anal receptive intercourse may develop rectal trichomoniasis which may be associated with a discharge.
(3) The urine sediment can be examined if the patient has pyuria but no urethral discharge.
(4) Semen
The number of organisms may also be affected by how active the infection is in the man's sexual partners and whether or not he wears a condom.
The most sensitive test for trichomoniasis is PCR or other amplification technology. However, calcium alginate swabs or feces may interfere with PCR, resulting in a false negative result.