HPV reactivation risk may increase in older women

Issue: January 2013

New data published online today from a 2-year, semiannual, follow-up study suggest that HPV reactivation risk may increase in women aged approximately 50 years — adding to an overall increased rate for HPV detection at older ages.

When compared with younger women, the population attributable risk for high-risk HPV genotypes was higher among older women who reported having five or more lifetime sex partners (28% vs. 87.2%). Conversely, the population attributable risk for high-risk HPV associated with having a new sex partner was 28% among those aged 35 to 49 years and 7.7% among women aged 50 to 60 years.

Patti E. Gravitt

“We are suggesting that we are not seeing an increase in HPV in older women in the US because women older than age 50 to 55 years in most previous studies had sexual debut before the sexual revolution, and were thus on average less likely to enter menopause with latent HPV infection,” Patti E. Gravitt, PhD, MS, of the department of epidemiology and W. Harry Feinstone department of molecular microbiology and immunology at Johns Hopkins Bloomberg School of Public Health, told Infectious Disease News. “Our prediction is that as the baby-boomer generation age and transition through menopause, we will begin to see a more clear increase in HPV at older ages.”

For the study, Gravitt and colleagues examined data on 843 women aged 35 to 60 years. Women were attending an outpatient OBGYN clinic for routine gynecological examination in and around Baltimore between 2008 and 2011.

Gravitt and colleagues estimated age-specific HPV prevalence defined by a lower risk for prior HPV infection (fewer than five lifetime sex partners) or a higher risk for prior infection (more than five lifetime sex partners).

The age-speciﬁc prevalence for 14 high-risk HPV genotypes decreased as age increased among women with fewer than five lifetime sex partners. The prevalence did not decrease among women with five or more partners (P=.01 for interaction).

“Our data suggest that HPV infections may not ‘clear’ after 1 to 2 years as we have said in the past, but rather they are ‘controlled below limits of detection’ after 1 to 2 years,” Gravitt said. “The implication of this is that any compromise of immunity could induce reactivation or recurrent detection of HPV infection acquired in the past. This is clearly observed in severely immune suppressed populations, like HIV-infected women and women with organ transplants.

“Our data, combined with the U-shaped HPV prevalence curve seen in other countries, suggest that reproductive and/or chronological aging may also result in sufficient changes to immune control of latent infection to induce recurrent detection, or reactivation, during the menopausal period,” she said. “Some may argue that these are prevalent infections and may have been persistently detectable for years before joining our study; however, in the Dec. 1, 2012 issue of Cancer Research, we show the same association between lifetime sexual partners and new HPV infection, which increases with age, as described in this study.”

In an accompanying editorial, Darron R. Brown, MD, and Bree A. Weaver, MD, both of the Indiana University School of Medicine, wrote: “Some previous studies demonstrating that HPV ‘clears’ after 2 years have been based on only one or two negative screenings. Several studies have shown that type-specific HPV can be detected again after a long period of non-detection, although whether this is due to reactivation of a low-level persistent infection or a new infection has not been established. … Further research is needed to help better understand the natural history of HPV infection in older women and to understand the importance of HPV persistence and reactivation in all women.”

For more information:

Brown DR. J Infect Dis. 2012;doi:10.1093/infdis/jis662.

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Gravitt PE. J Infect Dis. 2012;doi:10.1093/infdis/jis660.

Disclosure: The researchers report no relevant financial disclosures.