- Autores: Miguel Alpalhão, Luís Marques-Lito, Paulo Filipe, João Borges-Costa
- Ano de Publicação: 2021
- Journal: International Journal of Dermatology, 61(2), pp e49-e50
- Link: https://doi.org/10.1111/ijd.15769
We report the case of a 31-year-old male who presented to our Venereology Department with dysuria and a 2-year history of a minimal clear urethral discharge. He had been treated with multiple courses of antibiotics, namely, intramuscular ceftriaxone, azithromycin, ciprofloxacin, and doxycycline, even though laboratorial tests for Neisseria gonorrhoeae and Chlamydia trachomatis were consistently negative. The patient had psychological distress due to these persistent symptoms and for the lack of diagnosis as well as abstinence from any kind of sexual activity over the last 2 years. He denied any other complaints and also denied prior history of sexually transmitted diseases, other medical conditions, or current medication.
A urethral swab was taken for multiplex polymerase chain reaction (PCR; Allplex STI Essential Assay [Seegene]), which showed infection with Trichomonas vaginalis (TV). No other microorganisms were detected. A 7-day course of metronidazole 500 mg bid was prescribed. The symptoms resolved completely, and a follow-up PCR was negative for pathogenic microorganisms.
Trichomonas vaginalis, the causative agent of trichomoniasis, is highly prevalent in females in certain populations. TV prevalence is reported to be lower in Europe than in other geographic areas such as Africa. TV in men is almost always asymptomatic but occasionally may be a cause of nongonococcal urethritis in males and has been proposed to play a role in chronic prostatitis.1, 2 However, men may be an important reservoir for this microorganism and a vector for transmission.
While the classical laboratorial methods presented low sensitivity in these cases, nucleic acid amplification tests (NAATs) have been shown to be highly sensitive and specific for agent identification and are currently validated for the diagnosis of TV in both men and women.3 The Allplex assay used in our center has a reported sensitivity and specificity as high as 100% for TV detection, above 100 copies per reaction.4
These sensitive methods have shown TV to be found in as many as 3–17% of males visiting some sexually transmissible infection (STI) clinics.1, 5 Nevertheless, in Europe, these figures seem to be quite lower.6, 7
Over the last 10 years (2010–2020), a total of 91 laboratorial diagnoses of TV infection were made at Hospital Santa Maria, the largest tertiary teaching hospital in Lisbon, six (6.5%) in males. These patients were on average 35 years old (ranging from 19 to 59 years old). One infection was found through microscopic exam, while the remaining five were detected through multiplex PCR. Over the analyzed period, 1,689 multiplex PCR have been conducted on males, which translates to a rate of positivity for TV of 2.96 cases/1,000 tested males, which is similar to the 0.5% reported in the Netherlands.7
Clinically, four of these patients presented with urethritis, while one patient was under investigation for persistent genital ulcer. One patient had TV identified in a screening for STI, while asymptomatic, in the context of follow-up for human immunodeficiency virus (HIV) infection.
In the remaining three cases of urethritis, concomitant infection with Neisseria gonorrhoeae was detected through PCR, and in one case, Chlamydia trachomatis was also found. These cases were resolved with standard treatment for urethritis with ceftriaxone and azithromycin.
From our clinic, TV infection in men seems to be less frequent than in the published literature.2, 5 This is not related to diagnostic methods, as we routinely conduct multiplex PCR for STI diagnosis and screening.
Simultaneous coinfection with Neisseria gonorrhoeae (3/6) and Chlamydia trachomatis (1/6) was frequent in this population, which is concordant with the published data.
Our report confirms that TV may be a pathogen in male urogenital diseases, ranging from asymptomatic infection to recalcitrant urethritis. Multiplex PCR when routinely used for STI screening in men will identify those infected with TV. Directed treatment will reduce symptomatology, transmission to females, and ongoing morbidity.