Human Papillomavirus Infection Rate by Genotype and Vaccination Rates in Canada: Canadian Health Measures Survey 2009 to 2013

Abstract

AbstractBackgroundAn infection with certain HPV genotypes can lead to cancer or genital warts. HPV can be detected with PCR-based tests, and some genotypes can be prevented by vaccines. However, since the infection rates of various HPV genotypes have not been well reported, the present study aims to provide this information.MethodsThe Canadian Health Measures Survey (CHMS) is an ongoing biannual national survey. Between 2009 and 2011, it sampled a nationally representative sample of females aged 14 to 59 years to determine the infection rates of 46 HPV genotypes. Females aged 9 to 29 years and 9 to 59 years were asked whether they received HPV vaccines between 2009 to 2011 (cycle 2) and 2012 to 2013 (cycle 3), respectively. The reported infection rates and vaccination proportions were weighted and adjusted for the survey design.ResultsAmong the estimated 10,592,968 females aged 14 to 59 years at cycle 2, the HPV genotypes with the highest infection rates were 16, 62, 74, and 54, and the rates were 3.42% (95% CI = 1.67% to 5.17%), 2.14% (95% CI = 0.68% to 3.59%), 2.1% (95% CI = 0.51% to 3.69%), and 2.04% (95% CI = 0.38% to 3.7%), respectively. There were an estimated 6,569,100 and 11,603,752 females aged 9 to 29 and 9 to 59 years at cycles 2 and 3, respectively. The proportions receiving a HPV vaccine were 13.55% (11.18% to 15.92%) and 12.3% (9.8% to 14.79%), respectively. The estimated numbers of females that received HPV vaccines were 890,197 and 1,427,000, respectively.ConclusionCanada is one of the few countries that conduct national surveys to determine HPV infection rates by genotype, which are not limited to the surveillance of carcinogenic genotypes. Our study found discrepancies between the HPV genotypes whose infections were the most common, that could be detected by PCR tests, that were carcinogenic, and that could be prevented by vaccines. For example, 5 of the 7 genotypes (42, 54, 62, 66, and 74) with infection rates of more than 1% cannot be detected by PCR tests and are not targeted by vaccines. HPV 51 is carcinogenic, associated with genital warts, and can be detected by PCR tests, but it is not targeted by vaccines. We recommend a better alignment of the genotypes targeted by HPV tests and vaccines with those genotypes with the highest infection rates in Canada.