A new study suggests that human papillomavirus (HPV) infection in women after menopause may represent an infection acquired years ago. The HPV infections may exist below limits of detection after one to two years, similar to other viruses.
In previous studies, HPV has been detected in 25 to 50 percent of young, sexually active women. In most of these cases, after two years the virus is “cleared,” or is no longer detected in samples. Studies have shown that HPV infection peaks in young women around the age of sexual debut and begins to decline in the late 20s and 30s
Researchers, led by Patti E. Gravitt, PhD, of Johns Hopkins Bloomberg School of Public Health and Perdana University Graduate School of Medicine in Serdang, Malaysia, set out to investigate the factors influencing differences. They compared differences in recent and lifetime sexual behaviours by age groups, to investigate the presence of a cohort effect in a population of women in Baltimore.
The study included approximately 850 women aged 35-60 who were receiving routine cervical cancer screening from 2008 to 2011. While HPV prevalence was higher among women who reported a new sexual partner within 6 months prior to study enrolment, less than 3 percent of women in the study reported having a new partner in that time. Conversely, nearly 90 percent of HPV infections were detected in women reporting more than one lifetime sexual partner, and 77 percent were detected in women who reported five or more sexual partners in their lifetime.
According to the authors, “their historical experience with HPV and cervical neoplasia in postmenopausal women may not be very predictive of the experience of the baby boomer generation of women who are now entering the menopausal transition at a higher risk than their mothers,” Dr. Gravitt said. Reactivation risk increases around age 50 years and contributes to a larger fraction of HPV detection at older ages, compared with new acquisition.
Dr. Gravitt and her team of investigators will continue to follow the women in the study to further confirm their findings. A more nationally representative sample of women would help determine whether the study’s findings can be generalised to the larger U.S. population. “Long-term follow-up of previously highly exposed women who will transition through menopause in the next decade is urgently needed to accurately estimate the potential risk of postmenopausal invasive cervical cancer in the U.S. baby boom population and guide prevention strategies,” the authors wrote.
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.