Trichomonas infections in men

American Family Physician,  Feb, 1989  by John W. Saultz,  William L. Toffler

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Trichomonas Infections in Men

Trichomonas vaginalis, a common pathogen in the female genital tract, produces a characteristic clinical picture in women. Less well recognized are the manifestations of Trichomonas infestations of the male genital tract, which include urethritis and chronic prostatitis. Multiple-glass urinalysis and selective use of Trichomonas cultures may improve recognition of this organism in the family practice setting. Trichomonas vaginalis has long been recognized as a common cause of infection in the female genital tract. Characterized by a profuse, malodorous vaginal discharge, trichomoniasis is found in 20 to 50 percent of women presenting at sexually transmitted disease clinics because of vaginal symptoms. However, more than 50 percent of women with T. vaginalis infection have no symptoms at the time the organism is identified.[1]

Men also can harbor the organism without having symptoms. For this reason, and because of the high recurrence rate of vaginal trichomoniasis, simultaneous treatment of the male sexual partners of affected women has long been recommended. The diagnosis and treatment of primary symptomatic trichomoniasis in men have been less thoroughly studied and remain controversial.

Illustrative Case

A 37-year-old man was referred to our family practice center because of a six-week history of urinary hesitancy and urgency, accompanied by fatigue. The patient had sought treatment for similar symptoms at a local urgent care center on two occasions during the preceding four weeks. On each occasion, he was treated with a ten-day course of doxycycline for a presumed diagnosis of nonspecific urethritis. When the symptoms did not respond to doxycycline, he was referred to our center for further evaluation and possible referral to a sub-specialty clinic.

The patient had no history of exposure to sexually transmitted diseases, and he had a single, stable sexual partner. He denied any history of fever, chills or flank pain. There was no history of urinary tract infection, prostatitis or renal stones.

Physical examination revealed an afebrile man who appeared well and in no distress. His abdomen was soft, with general tenderness in the lower quadrants. No suprapubic tenderness or flank tenderness was noted. The genitourinary examination disclosed no scrotal masses or tenderness and no evidence of hernia or penile lesions. Rectal examination revealed a slightly soft, normal-sized, nontender prostate, with no palpable nodules.

Because of the history of nonspecific urethritis, a three-glass urinalysis was performed. The first glass (urethral washing) revealed 25 to 30 white blood cells per high-power field, occasional epithelial cells, no red blood cells and no casts. The second glass (bladder washing) revealed one to two white blood cells, no red blood cells and no casts. The third glass (prostatic secretions and residual urine after prostate massage) revealed eight to ten white blood cells and numerous T. vaginalis organisms per high-power field. Trichomonas organisms were not identified in the urine collected in the first and second glasses.

The patient and his sexual partner were both treated with metronidazole (Flagyl), 250 mg three times daily for ten days. Two weeks later, the patient was asymptomatic. Urinalysis at that time revealed no white blood cells, no T. vaginalis organisms, no red blood cells and no bacteria. Three-glass urinalysis was not repeated because the patient declined another prostate examination. The patient was still asymptomatic at six-month follow-up.

Forms and Frequency of Disease

While T. vaginalis has been recognized as a possible urogenital pathogen in men for over 50 years, the exact incidence of Trichomonas infections in men remains controversial. For the purposes of review, Trichomonas infections in men can be divided into three clinical syndromes: the asymptomatic carrier state, urethritis and prostatitis.

ASYMPTOMATIC CARRIER STATE

The asymptomatic Trichomonas carrier state is perhaps the best understood of the three syndromes. It has been studied primarily by investigators with an interest in sexually transmitted diseases in women. Trichomonas may be seen in the urethral specimens of 14 to 60 percent of the male sexual partners of women with trichomoniasis.[2] It is widely recognized that the recurrence rate of vaginal trichomoniasis is unacceptably high if sexual partners are not treated concomitantly. While studies have demonstrated the presence of T. vaginalis in the male genital tract, the incidence or prevalence of Trichomonas infestation in unselected populations has not been investigated.

URETHRITIS

The role of Trichomonas as an etiologic agent in male urethritis is somewhat controversial. Because laboratory evaluation fails to reveal the specific cause of 30 to 50 percent of the cases of nongonococcal urethritis, some authors have postulated that Trichomonas is an etiologic agent in this disorder.[2,3]

Reported prevalence rates of Trichomonas infestation in men with nongonococcal urethritis range from 1 percent in U.S. military men to 68 percent in a population of men studied in Chile. In 1981, Krieger[2] reviewed 13 studies dating back to 1953 and found a median prevalence of 11 percent for T. vaginalis infestation in men with nongonococcal urethritis.