Background Tests for Trichomonas vaginalis (TV) are often not performed on samples submitted from primary care because the prevalence is assumed to be too low for testing to be cost effective. Current microbiological testing involves wet mount microscopy (sensitivity 50%) or culture (sensitivity 75%). In practice, sensitivity rates may often be lower than this, due to deterioration of specimens during transport to the laboratory. The Aptima TV NAAT test has recently been approved for use (sensitivity ˜100%).

Aim To determine the positivity of TV in symptomatic and asymptomatic women at risk of an STI, seen in primary care using Aptima TV NAAT.

Methods The Aptima TV NAAT test was performed on 6716 remnant samples from women undergoing chlamydia and gonorrhoea NAAT testing in primary care.

Results The positivity of TV in symptomatic and asymptomatic patients from primary care was 2.6% (86/3271) and 1.2% (40/3445) respectively compared with an expected positivity of 0.3% and 0.1%, based on existing methods. TV positivity rates varied between GP practices from 0% to 4.8%. Higher positivity rates were observed in practices serving areas of deprivation, as well as those with higher black and minority ethnic populations.

Conclusions This is the first study to report TV positivity, using a TV NAAT, in unselected women presenting for STI testing in primary care. In view of the wide variation in positivity by locality, it is likely testing for TV will be cost effective in some areas. Ongoing surveillance may be necessary to identify those at risk.