SUNDAY, April 1 (HealthDay News) -- Human papillomavirus infection tends to lasts longer in college-aged black women than whites, possibly setting them up for a higher risk of cervical cancer, according to a new study.

The researchers also found that black women are 70 percent more likely to have an abnormal Pap test -- the screening for cervical cancer -- than their white counterparts. Human papillomavirus, or HPV, which is a sexually transmitted infection, can cause genital warts and is responsible for many cases of cervical cancer.

"African American women are more likely to have persistent high-risk HPV infection," said study author Kim Creek, vice-chair and professor of pharmaceutical and biomedical sciences at South Carolina College of Pharmacy, in Charleston.

Most HPV infections are transient. "If you are infected, your body recognizes it as a viral infection and usually clears the virus within one or two years," he said. "It is those women who have difficulty clearing it that are at higher risk of cervical disease and cervical cancer."

Exactly why black women have more difficulty clearing the virus is not known. "We think that it likely has something to do with the immune system," he said.

Lifestyle factors and genetic differences may also play a role. "We will try to understand why this occurs because if we could understand the reason for the difference, it would be easier to make public health recommendations about what to do about it," Creek added.

For the study, researchers assessed HPV infection and persistence in college-age women enrolled at the University of South Carolina. The study began in 2004, and the women were followed throughout their college years. HPV status was evaluated every six months in Pap test samples from 326 white women and 113 black women.

The rate of new high-risk HPV infection was similar between the two groups of women, the researchers found, but at any visit, black women were 1.5 times more likely to test positive for high-risk HPV infection. Also, 56 percent of black women were still infected two years after they were first diagnosed, compared with 24 percent of white women.

The findings are slated for presentation Sunday at the annual meeting of the American Association for Cancer Research, in Chicago.

Creek said that black women are 40 percent more likely to develop cervical cancer and two times more likely to die from the disease than European or American white women. This discrepancy is often attributed to lack of access to medical care, but the authors said their findings suggest a biological basis lies behind the varying rates.

Regular screening with the Pap test is the best way to prevent cervical cancer, Creek said. A sample of cells is scraped from a woman's cervix and examined under a microscope. If any abnormal or precancerous cells are detected, measures can be taken to prevent them from developing into cancer.

HPV vaccinations offer protection from the four types of HPV that cause most cervical cancers. These shots are currently recommended for 11- and 12-year-old girls and for females aged 13 to 26 who did not get any or all of the HPV shots when they were younger. The vaccines can be given to girls beginning at 9 years of age.

"African American women may benefit even more from the HPV shots," Creek said.

Dr. Diana Contreras, director of gynecologic oncology at Long Island Jewish Medical Center in New Hyde Park, N.Y., said it is way too early to draw any conclusions about screening and treatment of HPV in black women from this study.

"We are beginning to understand that HPV may behave differently in different ethnic groups," she said. "This study is very provocative, but the jury is still out on screening and treatment, and we have to be careful about drawing too many conclusions."

Data and conclusions of research presented at medical meetings should be considered preliminary until published in a peer-reviewed medical journal.

More information

Learn more about HPV infection at the U.S. Centers for Disease Control and Prevention.