What can surveillance of genital warts tell us?

In this Review, we describe the recent epidemiology of genital warts and postulate what the future may hold as a result of the introduction of the quadrivalent human papillomavirus (HPV) vaccine. HPV types 6 or 11 are responsible for most cases and they develop in about two-thirds of women a few months after HPV 6 or 11 infections are first detected by polymerase chain reaction. Surveillance data, cohort studies and cross-sectional surveys suggest that the annual incidence of genital warts exceeds 1% and serological studies suggest cumulative risk up to 40 years of age for HPV 6 or 11 is over 25%. The quadrivalent HPV vaccine is highly effective against genital warts and Australian surveillance data in the 2 years after the introduction of the vaccine have shown large declines in younger women and to a lesser degree heterosexual men. No significant changes in older women or men who have sex with men were seen. Given the success of Australia's catch-up program it will not be long before we know if the basic reproductive number for genital warts holds the prospect of elimination. However, if genital warts stabilise at a lower, but not very low, rate we will know that elimination will not be possible without vaccination of males.