Impact of replacing cytology with human papillomavirus testing for cervical cancer screening on the prevalence of Trichomonas vaginalis: a modelling study

Abstract

Our modelling suggests that in a setting like Australia, where TV can be detected incidentally through cytology-based cervical screening, a transition to HPV testing is likely to result in increasing TV prevalence over time unless additional measures are implemented to increase TV testing and treatment.

The dawn of novel STI prevention methods: modelling potential unintended effects of changes in cervical cancer screening guidelines on trichomoniasis

“…Hui et al 5 have used mathematical modelling to estimate potential indirect effects of the cervical screening guideline changes on TV prevalence in Australia. In the study, a deterministic compartmental model of TV transmission among heterosexual population was calibrated to low-level (0.4%) TV prevalence reflecting urban Australian population and assuming a steady age-specific cytology-based cervical cancer screening rate among women over 18 years.…”

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

“…We recently used a mathematical model to show that TV prevalence could increase more than sixfold over 20 years if the transition to the revised cervical screening programme is not supplemented with additional strategies for detection of asymptomatic TV infection 8. The reason for this predicted increase in TV prevalence is twofold: first, under the new screening algorithm, only women who test positive for high-risk (HR) HPV will be referred for cytology; thus, those with asymptomatic TV infection but HR-HPV-negative will elude detection and treatment; second, the increase in the age of commencement of screening (25 years rather than 18 years) and the increased screening interval (5-yearly rather than 2-yearly) mean fewer TV infections will be detected.…”

“…To offset an increase in TV prevalence predicted to occur with the transition from cytology-based cervical screening to screening based on HPV testing, it will be necessary to implement some form of opportunistic or routine screening. Here we used our previously developed model8 to estimate the scale of intervention required to maintain control of TV prevalence and evaluate two potential scenarios for supplementing TV testing.…”

Highlights from this issue

“…With Trichomonas vaginalis (TV) we are also seeing a restructuring of vulnerability in developed countries through the impact of new approaches to cervical cancer screening, which is nicely explored in Rönn et al ’s editorial 4. The authors reflect on a mathematical modelling study by Hui et al 4 and explore the interactions between technological, social and biological determinants in the context of reduced detection through cervical screening.…”

“…The authors reflect on a mathematical modelling study by Hui et al 4 and explore the interactions between technological, social and biological determinants in the context of reduced detection through cervical screening. While this month’s Natsal-3 report by Field et al 5 confirms that rates of TV are very low in the UK population, both TV and cervical screening uptake vary markedly within population groups and serious consideration needs to be given to ensuring detection in women at greatest risk.…”