Fall in Genital Warts Diagnoses in the General and Indigenous Australian Population Following Implementation of a National Human Papillomavirus Vaccination Program: Analysis of Routinely Collected National Hospital Data

BACKGROUND: Human papillomavirus (HPV) vaccination targeting females aged 12-13 years commenced in Australia in 2007, with catch-up vaccination of females aged 13-26 years continuing to 2009. Whole-population analyses, including effects on the Indigenous population, have not previously been reported. METHODS: All hospital admissions between 1999-2011 involving a diagnosis of genital warts were obtained from a comprehensive national database. We compared the age-specific rates before to those after implementation of the vaccination program, according to sex and other characteristics. RESULTS: Admission rates decreased from mid-2007 in females aged 12-17 years (annual decline, 44. 1% 95% confidence interval CI, 35. 4%-51. 6%) and from mid-2008 in females and males aged 18-26 years (annual declines, 31. 8% 95% CI, 28. 4%-35. 2% and 14. 0% 95% CI, 5. 1%-22. 1%, respectively). The overall reductions from 2006-2007 to 2010-2011 were 89. 9% (95% CI, 84. 4%-93. 4%) for females aged 12-17 years, 72. 7% (95% CI, 67. 0%-77. 5%) for females aged 18-26 years, and 38. 3% (95% CI, 27. 7%-47. 2%) for males aged 18-26 years. Compared with the average annual number before program implementation, about 1000 fewer hospital admissions involved a warts diagnosis during 2010-2011. Reductions after program implementation were similar for Indigenous (86. 7% 95% CI, 76. 0-92. 7) and non-Indigenous (76. 1% 95% CI, 71. 6%-79. 9%) females aged 15-24 years (P (heterogeneity) =. 08). CONCLUSIONS: National population-based hospital data confirm previous clinic-based reports of a marked decline in genital warts diagnoses among young people in Australia after program implementation, including indirect benefits to males. The impact of HPV vaccination appears to be similar in young Indigenous and non-Indigenous females.