A high prevalence of Trichomonas vaginalis was found among men and women, and researchers from the University of Alabama at Birmingham suggest that both should be routinely screened.
They also found that among women, a nucleic acid amplification test (NAAT) detected more infections than wet mount alone.
“The gold standard for T. vaginalis diagnosis in women has been culture of vaginal fluid … [but] T. vaginalis culture is not readily available in clinical settings and sensitivity is less compared to the recently available, highly sensitive NAAT,” the researchers wrote in Clinical Infectious Diseases. “The T. vaginalis NAAT has been validated in asymptomatic and symptomatic women in multiple specimen types and is run on the same instrumentation platforms for Chlamydia trachomatis and Neisseria gonorrhoeae testing.”
The researchers reviewed data of 6,335 men and women who presented to the local STD clinic and received an NAAT for T. vaginalis. From March 2012 to September 2013, 3,821 women received an NAAT on an endocervical or urine specimen, and from November 2012 to September 2013, 2,514 men received an NAAT on urethral or urine specimens.
The overall prevalence of T. vaginalis was 20.2%. Among women, the prevalence was 27%, and among men, the prevalence was 9.8%. Besides an NAAT, 3,765 women also underwent wet mount testing, in which the prevalence was 19.6%. An NAAT detected one-third more infections than wet mount.
Among the women who had both wet mount and NAAT results, 301 women who were negative according to wet mount were positive according to NAAT. Sixteen women were positive on wet mount, but negative on NAAT.
“This study demonstrates that routine implementation of T. vaginalis NAAT at our STD clinic was able to detect a significant proportion of infected male and female patients, significantly higher than that detected by wet mount alone in women,” the researchers wrote. “Improved detection of T. vaginalis by implementation of NAAT in men and women of all age groups should be considered, as it will likely result in better control of this common, treatable STI.”
Disclosure: One researcher has been a consultant for and received research support from BD Diagnostics, Cepheid, Embil Pharmaceuticals and Hologic/Gen-Probe.