Recently CDC researchers published two analyses looking at the prevalence of HPV among women in the United States. The first, an updated estimate of the prevalence of HPV, found that during 2003-2006, 42.5 percent of women aged 14-59 years were infected with at least one of 37 types of genital HPV. In a second analysis limited to the prevalence of the four types of HPV that are vaccine-preventable in the same time period, researchers found that prevalence was highest among young women aged 20-24 years.
It’s important to note that although the body naturally clears about 90 percent of infections within two years, some high-risk types persist and can cause cervical cancer in women. There are two vaccines available to protect against the types of HPV that cause most cervical cancers.
Authors also underscore that HPV DNA prevalence estimates offer a snapshot of the number of women infected with HPV at a given point in time, but they do not reflect past infections or the risk for future infection. Therefore, these estimates do not fully capture the magnitude of HPV infection in the United States. Despite these limitations, the studies will offer a baseline for measuring the early impact of available vaccines and for monitoring changes in HPV prevalence.
The studies, published this week in the Journal of Infectious Diseases, are available online at:http://jid.oxfordjournals.org/content/current.
- Prevalence of Genital HPV among Females in the United States, the National Health and Nutrition Examination Survey, 2003-2006
Overall, HPV Infection Commonly Affects Young Women in the U.S.
An analysis led by CDC’s Dr. Susan Hariri analyzed overall HPV prevalence among women aged 14-59 years in the U.S. during 2003-2006, finding that nearly one-half of women (42.5 percent; or 39.5 million women) were infected with at least one of 37 types of genital HPV. Prevalence of HPV infection was lowest among 14-19-year-old females (32.9 percent) and highest among 20-24-year-old females (53.8 percent).
The research shows that HPV prevalence is associated with poverty, number of sexual partners, age at sexual debut, and marital status.
- Human Papillomavirus (HPV) 6, 11, 16 and 18 Prevalence among Females in the United States – National Health and Nutrition Examination Survey, 2003-2006: Opportunity to Measure HPV Vaccine Impact?
Young Women Have the Highest Prevalence of Vaccine-Preventable HPV
A separate analysis, led by CDC’s Dr. Eileen Dunne, examined the prevalence of vaccine-preventable high-risk HPV types 16 and 18, responsible for 70 percent of cervical cancers, and low-risk HPV types 6 and 11, responsible for nearly all genital warts, during 2003-2006. Researchers found that 8.8 percent of women aged 14-59 years in the United States were infected with at least one of these types of HPV. Further, by age, prevalence of infection with any of the four types was highest among women aged 20-24 years (18.5 percent).
By types, prevalence of types 16 and 18 was highest among women aged 20-24 years (12.5 percent and 3.6 percent respectively). Prevalence of types 6 and 11 was highest among women aged 14-19 years (5.4 percent and 1.0 percent respectively).
How the New Data Update Previous NHANES Analyses of HPV Prevalence
The data published today are an update of a 2007 analysis published in the Journal of the American Medical Association examining HPV prevalence among women using only data from 2003-2004.
Though findings from both the current and previous studies are based on data from CDC’s National Health and Nutrition Examination Survey (NHANES), a nationally-representative survey of the U.S. household population that assesses a broad range of health issues, the current study incorporates two additional years’ worth of data – 2005 and 2006.
Authors believe this updated prevalence estimate is higher than the previous estimate because an improved HPV test — which detects HPV at lower quantities – was used for this study.
For more information about HPV and the HPV vaccine, visit: http://www.cdc.gov/hpv/.