Question
What are the clinical manifestations, diagnostic methods, and management procedures of T. vaginalis infections?

Study Selection Criteria
A Medline search, limited to English language and publication within the previous 10 years, was performed using keywords.  Articles were limited to “trichomoniasis” or “Trichomonas vaginalis” in their titles.  Articles were excluded if the focus was not clinically relevant.  Only the most recently published articles were selected from a developing body of literature.  

Data Extraction
One hundred ninety-five articles with “trichomoniasis” or “Trichomonas vaginalis” in their titles were retrieved.  Of these, 94 abstracts were reviewed and 52 of these were selected and included in the review.

Main Results
This review includes the epidemiology, clinical presentation in women and men, diagnosis, and treatment of T. vaginalis infections.  This summary will describe the main points of the review that discuss T. vaginalis diagnosis.  

Suitable clinical specimens for T. vaginalis detection include urine, vaginal fluid, semen, self-collected vaginal specimen, and endocervical smear.  Testing from multiple sites per patient is recommended.   Laboratory detection methods include: 1) microscopic examination of a wet mount preparation or a Papanicolaou smear, 2) culture followed by microscopic examination, 3) molecular probes, and 4) nucleic acid amplification.  Wet mount specimens suspended in normal saline and culture specimens are examined for motile trichomonads.  Wet mounts are inexpensive and rapid.  Culture in Diamond’s modified medium or the InPouch TV system is more sensitive than wet mount but is more expensive and requires more time to complete (3 to 7 days to diagnosis).  Culture may be performed after a negative wet mount result on specimens from a high prevalence population.  Pap smears perform with low sensitivity (61%).  Molecular probe methods are rapid and as sensitive as wet mount but require specialized equipment, skilled laboratory personnel, and are expensive.  Nucleic acid amplification methods such as PCR have the advantage of detecting either viable or non-viable organisms and as few as one organism per reaction.  They can be performed on vaginal fluid, urine, or self-collected vaginal swabs.  Urine-based PCR detection had a sensitivity and specificity of 64 to 90.8% and 93.4 to 100% in US women, and 92.7% and 88.6% in African men, respectively.  

The WHO has developed syndromic management algorithms for STD diagnosis.  The urethral discharge algorithm does not consider trichomoniasis until after the patient has been treated for gonorrhea and chlamydia.  The vaginal discharge algorithm performs poorly for T. vaginalis infection.  Only one in three South African antenatal clinic attendees treated for trichomoniasis based on a risk score would have been correctly diagnosed with trichomoniasis based on wet mount microscopy.  Overtreatment using syndromic management compared to laboratory diagnosis has been observed.   

Authors’ Conclusions
T. vaginalis disease presentation is variable and diagnosis can be difficult with the most commonly used methods.  Sociodemographic and behavioral risk factors may assist in predicting infection.  However, women and men without any symptoms escape detection and treatment under syndromic management recommendations, requiring increased screening efforts.    

Source of funding:  None given 

For correspondence:  Heidi Swygard, CB#7030, 130 Mason Farm Road, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7030.  E-mail address: heidi.swygard@med.unc.edu.