Background: Australia introduced a national human papillomavirus (HPV) quadrivalent vaccine program for 12–13-year-old girls in mid 2007, with a catch-up program for 14–26-year-old women till 2009. Since, sentinel surveillance has shown a large decrease in proportion of vaccine-eligible women diagnosed with genital warts at outpatient sexual health services. This analysis assessed trends in inpatient treatments for genital warts.
Methods: Data on in-patient treatments of warts in men and women were extracted from Medicare (Australian universal health insurance scheme) website. We used χ2 statistics to determine trends in inpatient treatments before and after 2007, stratified by age groups and anatomical site.
Results: Between 2000 and 2011, 6014 15–44-year-old women underwent inpatient treatments for vulval/vaginal warts. In women aged 15-24 years (eligible for vaccination in 2007), there was no trend in number of treatments before 2007(p=0.73); however, there was a 85% decline after 2007(p<0.01). In women aged 25-34 years, there was 24.2% decline before 2007(p<0.01) and 33.3% decline after 2007(p<0.01); and in 35–44-year-old women there was no decline(p=0.07). In 2000-2011, a total of 936 15–44-year-old men underwent treatment for penile warts, and 3398 men for anal warts. There was a 200% increase in penile wart treatments in men aged 15-24 years before 2007(p<0.01) and 70.6% decline after 2007(p<0.01). In 25–34-year-old-men there was no decline before 2007(p=0.27) and 59% decline after 2007(p<0.01). There was no decline in men aged 35-44 years(p=0.11). There was no decline in anal warts treatments in men.
Conclusions: This is the first study to look at impact of vaccine program on treatment of severe cases of genital warts. The marked decrease in numbers of vulval/vaginal wart treatments in youngest women is attributable to the vaccine program; moderate decrease in in-patient treatments for penile warts in men probably reflects herd immunity.