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The use of specimens from various genitourinary sites in men to detect Trichomonas vaginalis infection.
Kaydos-Daniels SC, Miller WC, Hoffman I, Price MA, Martinson F, Chilongozi D, Namakwha D, Gama S, Phakati S, Cohen MS, Hobbs MM
J Infect Dis
2004; 139:926-31
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John N. Krieger, M.D.
University of Washington
School of Medicine |
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This well-designed study reemphasizes an important, but sadly underappreciated observation. Evaluation of multiple specimens is superior to use of a single specimen to diagnose
Trichomonas vaginalis infection in men.
Diagnosis of trichomoniasis is important. Infection is very treatable. Urogenital symptoms associated with trichomoniasis cause considerable morbidity, especially related to vaginitis in women and urethritis in men. Trichomoniasis is associated with an increased risk of HIV infection and with increased perinatal morbidity. Diagnosis of trichomoniasis supports recommendations for evaluation and treatment of other sexually transmitted infections, in addition to counseling in risk reduction strategies.
Consistent with earlier studies [1,2,3], the authors found that culture of urethral swab and first-void urine specimens had similar sensitivity. In this research study use of either specimen alone diagnosed 67% of infections. In the field, one would expect test performance to be lower because of less optimal specimen handling, processing and laboratory evaluation. Also consistent with previous reports, the authors found that culture of the semen provided higher sensitivity than any other sample, with 26% of infections detected by semen culture only.
This study has important strengths. The selection of participants is described clearly. The clinical and diagnostic methods are thorough, well described and appropriate. The large sample size of 1,361 participants was adequate for the statistical comparisons. At enrollment 100
T. vaginalis infections were diagnosed, representing 7% of the entire cohort.
The authors’ conclusion about one stated objective remains unclear. One goal was, “to evaluate syndromic management of urethritis…in Lilongwe, Malawi.” Their STD clinic population had a 44% prevalence of infection with
Neisseria gonorrhoeae, a 47% prevalence of HIV infection, and 7% had positive syphilis serology. Their other population was also at high risk by most standards. In this dermatology clinic population, the prevalence of gonorrhea was only 0.2%, but 28% had HIV infection, and 4% had positive syphilis serology test results. This study documented a 9% prevalence of
T. vaginalis infection in the STD clinic population and a 3% prevalence of
T. vaginalis infection in the dermatology clinic population at the initial visit. Given this high prevalence in both populations, the cost, and technical difficulties in diagnosing urogenital trichomoniasis, many authorities would agree that syndromic management of urethritis in either population should include treatment for trichomoniasis. The author’s thoughts on the relative merits of such syndromic management versus routine diagnostic testing for trichomoniasis would be of interest.
PCR-based diagnostic tests for T. vaginalis infection have been described and the authors suggest that their population may offer considerable advantages for evaluation of these tests in both men and women. Whether such tests will provide sufficient sensitivity to provide accurate diagnosis with a single urogenital specimen is an important question.
References
1. Krieger JN, Verdon M, Siegel N, Critchlow CC, Holmes KK. Risk assessment and laboratory diagnosis of trichomoniasis in men. J Infect Dis 1992;166:1362-66.
2. Krieger JN, Verdon M, Siegel N, Holmes KK. Natural history of urogenital trichomoniasis in men. J Urol 1993;149:1455-58.
3. Watt L, Jennison RF. Incidence of Trichomonas vaginalis in marital partners. Br J Vener Dis 1960;36:163-66.
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