Study: Dormant HPV can reactivate and boost cervical cancer risk

Human papillomavirus, the incurable sexually transmitted virus that causes cervical cancer, can be reactivated after lying quiet in the body for years, which can help explain why HIV-positive women have high rates of the cancer, U.S. researchers reported Wednesday. Their study of 2,500 women, who were examined every six months for an average of seven years, showed those who were HIV-positive were much more likely to also be infected with HPV, which is the main cause of cervical cancer. Most of the women became infected with HPV at some point, but it became undetectable later, apparently because the immune system can control it. But the researchers identified 29 HIV-positive women who also had an HPV infection, cleared it, and had it come back--even though the women had been celibate for 18 months or more. This fits "a stringently defined pattern highly consistent with HPV reactivation," the researchers wrote in their report, published in this week's issue of the Journal of the National Cancer Institute. "That is, an initially detected HPV type was subsequently not detected for at least two sequential visits and then was detected a second time, in a subject who had remained sexually inactive from the time the HPV type became undetectable and then detectable again (minimizing the possibility of new sexual transmission)." Howard Strickler of Albert Einstein College of Medicine in New York and colleagues at eight other institutions said their findings suggest that HIV-positive and perhaps other women with suppressed immune systems, such as transplant and cancer patients, need to have regular Pap smears to detect cervical cancer in its earliest and most treatable stages. "Our data suggest that undetectable HPV infections become active much more frequently in HIV-positive women, which helps explain the extremely high rates of HPV infection in these women," Strickler said in a statement. The study supported the idea that HPV is transmitted sexually. Women were much more likely to be infected with HPV after a recent sexual encounter. "Even one male sexual partner among married women (presumably a monogamous relationship with the subject's husband) was associated with risk of incident HPV detection," the researchers wrote. (Reuters)