WP 119 Why Are Anogenital Warts Diagnoses Decreasing in the UK Bivalent HPV Vaccine Cross Protection or Failure to Examine?

Tuesday, June 10, 2014
International Ballroom
Emily Clarke, BSc(Hons) BM DMCC DLSHTM MSc MRCP(UK)1, Chris Board, medical student2, Natasha Patel, Medical Student2, Lindsay Atkinson, .2, Hugh Tulloch, Medical student2 and Raj Patel, FRCP1, 1Department of Sexual Health, Royal South Hants Hospital, Southampton, United Kingdom, 2Faculty of Medicine, University of Southampton, Southampton, United Kingdom

Background:  Rates of first episode anogenital warts diagnoses in the UK have fallen from a peak prevalence of 151.9/100,000 population in 2008 to 139.1/100,000 in 2012, an 8% reduction. In Australia, the quadrivalent human papilloma virus (HPV) vaccination strategy has led to an unexpected reduction in warts diagnoses in unvaccinated males and older people, resulting in speculation that the UK decrease may be due to cross protection from the bivalent HPV vaccination programme for teenage girls introduced in 2008. However over a similar time period many sexual health clinics have introduced asymptomatic screening pathways which exclude examination.

Methods:  Records of all patients with a diagnosis of first episode warts attending a level 3 UK sexual health clinic between 01/01/10 and 11/02/10 (when no asymptomatic screening pathway was in place and all patients were examined) were interrogated. A random sample of consultants attending a national UK sexual health meeting were interviewed about asymptomatic screening pathways at their clinic.

Results:  Of 106 patients with a diagnosis of first episode warts, 81.13% were symptomatic, 6.60% were asymptomatic for warts but symptomatic for other conditions, and 12.26% were asymptomatic. 28 consultants were interviewed of whom 71.43% had asymptomatic screening pathways at their clinic introduced over a time period from 6 years to 6 months previously and, at these clinics, 24.09% patients were screened on an asymptomatic pathway.

Conclusions:  Failure to examine asymptomatic patients may lead to up to 12.26% of warts diagnoses being missed, and therefore the introduction of asymptomatic screening pathways across the UK may account for a considerable proportion of the reduction in warts diagnoses seen. This may decrease further in future as more clinics introduce asymptomatic screening pathways, and may make interpretation of the effect of the quadrivalent HPV vaccine in the UK (introduced in 2012) difficult to assess.