The finding came from new research, published in The Journal of Infectious Diseases, which suggests that after one or two years, HPV may exist below limits of detection. This is comparable to other viruses, such as varicella zoster, which leads to shingles.
The report emphasizes that more studies need to be conducted in order to gain more knowledge on HPV infections and understand the part that HPV persistence and reactivation play, especially in females of the baby boomer age.
Prior research has shown that about one in four females between the ages of 14 and 59 in the United States have HPV, and previous reports have detected HPV in about 25 to 50 percent of young women who are sexually active. However, in the majority of these females, the virus is "cleared" after two years and cannot be identified in their samples anymore.
Research has demonstrated that HPV infection is most common in young women when they become sexually active. The prevalence then tends to reduce once they reach their late 20s and 30s.
HPV has been shown to also be very common around the age of menopause in countries such as Central and South America. However, the incidence of HPV in the United States and Europe has been shown to decrease as women get older.
A team of experts, led by Patti E. Gravitt, PhD, of Johns Hopkins Bloomberg School of Public Health and Perdana University Graduate School of Medicine in Serdang, Malaysia, wanted to examine what factors affect these dissimilarities.
They analyzed the differences in recent and lifetime sexual behaviors in females of different age groups in order to observe the existence of a cohort effect in women in Baltimore.
An estimated 850 females between the ages of 35 to 60 were involved in the study who were undergoing routine screening for cervical cancer from 2008 to 2011.
Results showed that women who had a new sexual partner 6 months before the study began experienced a higher prevalence of HPV, however, less than 3% reported having a new partner in that period.
Almost 90% of HPV infections were found in females who said that they had more than one sexual partner in their lifetime, and 77% were found in women who had five or more sexual partners.
"Taken together, our data raise the possibility that reactivation risk may increase around age 50 years and contribute to a larger fraction of HPV detection at older ages, compared with new acquisition," the scientists wrote.
The results showed that women who became sexually active during and following the sexual revolution of the 1960s and 1970s are at a considerably increased risk of HPV infection than females who had their sexual debut before 1965. The authors believe that the reason is because of a greater number of sexual partners throughout their life.
Dr. Gravitt explained:
"Our 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."
Darron R. Brown, MD, and Bree A. Weaver, MD, of the Indiana University School of Medicine, explained in an accompanying editorial that prior research which indicated that HPV goes away after two years was only based on one or two screenings that came up negative.
Many reports have demonstrated that type-specific HPV can be detected again after not being detected for a long time. However, scientists are unsure whether it is because of a low-level persistent infection or a new infection.
"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," the authors wrote.
In order to verify their results, Dr. Gravitt and her colleagues will carry on with their research and further observe the women in the investigation.
To determine whether the results of this research can be generalized to the larger American population, future research needs consist of a more nationally representative sample of females.
The experts said:
"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."
Written by Sarah Glynn