Detecting asymptomatic Trichomonas vaginalis in females using the BD ProbeTec™ Trichomonas vaginalis Qx nucleic acid amplification test
Lord E., Newnham T., Dorrell L., Jesuthasan G., Clarke L., Jeffery K., Sherrard J.
Trichomonas vaginalis (TV) rates in women are increasing and many are asymptomatic. Nucleic acid amplification tests (NAATs) are becoming the ‘gold standard’ for diagnosis. We aimed to establish our asymptomatic TV rates by testing all women attending Oxfordshire’s Sexual Health service, regardless of symptoms, using the BD ProbeTec™ TV Qx NAATs (BDQx). During BDQx’s verification process, the sensitivity and specificity were calculated using results of 220 endocervical samples from symptomatic women, compared with culture. BDQx was subsequently implemented and prospectively evaluated over 6 months in female attendees. Wet mount microscopy was also performed in symptomatics. Demographic and clinical characteristics of those diagnosed were analysed. From 220 samples tested by BDQx and culture: 5 were positive on both and one solely using BDQx, giving a sensitivity and specificity of 100% and 99.53%, respectively. In the prospective cohort, of 5775 BDQx tests, 33 (0.57%) were positive. 11/33 (33%) patients were asymptomatic. All patients diagnosed had risk factors: age >25 years (85%), residence in a deprived area (79%) and black ethnicity (21%). Despite BDQx being highly sensitive and specific, with our low TV prevalence universal screening may not be justified. Targeted screening using local demographic data merits further investigation.