Supplemental Trichomonas vaginalis testing is required to maintain control following a transition from Pap smear to HPV DNA testing for cervical screening: a mathematical modelling study.

OBJECTIVES: Using mathematical modelling, we have previously shown that the prevalence of infection with Trichomonas vaginalis (TV) is likely to increase in the general population in Australia with the transition from Pap smear-based cervical screening to human papillomavirus (HPV) DNA testing. Here we use the existing model to estimate the level of supplemental testing required to maintain TV control.

METHODS: A compartmental mathematical model describing the transmission of TV in the general heterosexual population in Australia was used to evaluate the impact of a range of screening scenarios on TV prevalence over time following the transition to HPV DNA testing for cervical screening. Scenarios considered were the inclusion of a TV test with the HPV test and the addition of TV testing to routine chlamydia testing conducted in primary care.

RESULTS: Our modelling suggests that with sufficient coverage, inclusion of TV testing with routine chlamydia screening in general practice, TV prevalence can be reduced over time, but at the current reported coverage will gradually increase following the transition to HPV testing. Inclusion of TV testing with HPV testing in the cervical screening programme is preferable to no supplemental testing but is considerably less effective in controlling TV.

CONCLUSIONS: These findings support the inclusion of TV testing with routine chlamydia testing of young people.