October 19, 2006 (AIDSmeds)—Human papillomavirus (HPV) infection of the anus is more common than HPV infection of the cervix in HIV-positive women, according to new data reported last week at the 44th Annual Meeting of the Infectious Disease Society of America (IDSA) in Toronto.

HPV, spread primarily through sexual activity, affects approximately 40 million people in the United States. It can cause warts, dysplasia (abnormal patches of cells), and cancer in or around the genital area.

Research has established that HIV-positive people are more likely to be infected with HPV than HIV-negative people. HIV-positive people are also more likely to develop genital warts, as well as cervical or anal cancer, as a result of HPV infection.

While there is no shortage of data indicating that HPV-related infection is common in HIV-positive women, little is known about their risk for anal infection. Early studies have suggested that it is a risk. Research has also demonstrated anal HPV infection can occur in people who have never had anal sex.

At IDSA, Erna Kojic, MD, of Brown University Medical School and her colleagues presented data involving 122 HIV-positive women participating in a five-year, 1,000-person observational cohort (the SUN study). Samples to test for cervical and anal HPV infection were collected from the women upon entering the study.

The 122 women were between 21 and 64 years of age and predominantly African American. The vast majority of women were receiving HIV treatment and, upon entering the study, had average CD4 (T4) cell counts of 419 and viral loads of 200.

HPV infection of the anus and/or cervix was documented in 112 (92%) of the women. Anal samples were positive for HPV in 92% of the women, compared to positive cervical samples in 86% of the women. What’s more, high-risk HPV types – viral strains associated with an increased risk of cancer – were detected in 84% of the anal samples, compared to 64% of the cervical samples. Low-risk HPV types – strains known to cause warts and low-grade (non-cancerous) dysplasia – were found in 74% of the anal samples and 59% of the cervical samples.

Comparing the sample results to the results of questionnaires evaluating the women’s sexual histories, very few women positive for anal HPV infection reported ever having anal sex of any kind. In turn, Dr. Kojic’s group confirmed that anal HPV infection is not dependent on transmission via anal sex and that anal infection may result from the virus migrating from other genital regions.

The authors also concluded that much greater attention needs to be paid to anal HPV infection in HIV-positive women, including more research into the prevalence, severity, and treatment of HPV-related anal disease. Dr. Kojic also said that studies of HPV vaccines, such as the recently approved Gardasil®, need to be conducted in HIV-positive women to determine their potential benefits in terms of reducing the risk of anal and cervical infection and disease.