The acquisition of cervical human papillomavirus (HPV) infection is one of the main risk factors for cervical cancers. Multiple studies have shown that this virus is present in a large percentage of patients with cervical cancers. Some studies have suggested that this virus can be transient in the majority of women. However, women who do not spontaneously clear the virus are at higher risk for cervical cancer than women who do clear it. Franco and associates studied the natural course of HPV in a population at high risk for cervical cancer.
The study was performed at a maternal health program that served low-income women in Brazil. Women who met the inclusion criteria and agreed to participate for two years were enrolled in the study. The women were followed every four months for the first year, then every six months for subsequent years up to five years. Cervical samples were obtained at each visit and analyzed for HPV DNA and typed.
A total of 1,425 women participated in the study. Of these women, 357 tested positive for HPV at least once during the study. New infections occurred at a rate of 1.3 percent per month during the study. The monthly clearance rate was higher for nononcogenic HPV types than for the oncogenic types. The mean duration of infection was 8.2 months for the nononcogenic HPV types and 13.5 months for the oncogenic types.
The authors conclude that cervical HPV tends to be a transient infection in the majority of women, even those who are considered at high risk for cervical cancer. This is particularly true for the nononcogenic HPV viral types. Understanding the epidemiology of cervical HPV is an important step in developing strategies for preventing cervical cancer.
editor's note: A significant number of advances have been made in our understanding of cervical HPV infection. With these advances come questions about evaluating patients with cervical HPV infection. The current recommendation is for all women with cervical HPV to be evaluated by colposcopy. However, with more studies suggesting this is a transient infection, new thought needs to be given to a strategy of observing the infection with repeat Papanicolaou smears. The answer to this question, in my opinion, has not been resolved by any of the studies so far published.—k.e.m.