Human papillomavirus or HPV, which can cause cervical cancer, may also infect the anus — but the infection appears to resolve relatively quickly, researchers report.

"This fact may help explain why anal cancer among women is so much rarer than cervical cancer," Dr. Yurii B. Shvetsov told Reuters Health.

Dr. Shvetsov of the Cancer Research Center of Hawaii, Honolulu and colleagues examined the factors associated with anal HPV infection and its clearance in 431 women.

During an average follow-up period of 1.2 years, 50 percent of the women incurred a total of 414 anal HPV infections. Of these, 58 percent cleared during follow-up, the team reports in the medical journal Clinical Infectious Diseases.

The average duration of infection of the types of HPV considered high risk was 150 days, although this varied from type to type.

Delayed clearance was linked to douching, long-term smoking, and having anal sex.

Testing for cervical HPV is a way to screen for possible cervical cancer. However, the fact that anal infections are relatively short-lived "raise the possibility that anal HPV testing might be a less effective cancer screening tool, as compared to cervical HPV testing," continued Dr. Shvetsov.

"Whether or not anal HPV testing should become a generally accepted cancer screening tool," he concluded, "is an important question that should be addressed in future studies."