Q. I've heard there's a sexually transmitted disease called HPV that can cause cancer. What is HPV, and what do I need to know about it?

A. HPV (human papilloma virus) is one of the most common sexually transmitted diseases. There are more than 100 strains of the virus. Some types cause genital warts, while others can lead to the development of cancer of the cervix, vagina, vulva, penis or anus. It has been estimated that at least 20 million people in the United States have HPV.

HPV is spread through skin-to-skin contact, and can be spread from mother to fetus during childbirth. This has resulted in some children developing warts on the larynx (the inside of the throat). HPV can be contracted, remain dormant and later be transmitted to another sexual partner. It can take many years before HPV causes symptoms.

People who have a low-risk strain of HPV can develop visible warts on their genitals, or the infection may have few or no symptoms. Those who have a high-risk strain of HPV (which can lead to cancer) usually don't know they have the virus because there are no visible symptoms. Among women, HPV is often detected only because of an abnormal Pap test, which is followed by a special test (an HPV DNA test) to determine whether she has the virus, and if so, what strain. If a woman's Pap test results show very abnormal cells, her doctor will recommend a more detailed exam of her cervix called a colposcopy, which may include a biopsy.

At present, it is not possible to adequately test men for HPV.

Treatment for HPV is available, but there is no cure. Topical solutions, surgery (including cryosurgery, or freezing), and laser treatments may all be used. Natural therapies can also help by boosting immunity to fight the infection, and by treating the cervix with vaginal suppositories containing herbs and vitamins.

Condoms can help reduce the risk of contracting HPV, but their effectiveness is limited. It is important for sexually active women to have regular Pap tests to identify and promptly treat cervical lesions that may arise. For more information on HPV, see the HPV Resource Center on the American Social Health Association's Web site (www.ashastd.org), or read "Women At Risk: The HPV Epidemic and Your Cervical Health" by Dr. Gregory Henderson and Batya Yasgur (Avery Publishing, 2002).

Laurie Steelsmith is a naturopathic physician and licensed acupuncturist in Honolulu. You can contact her and read her past columns at www.drlauriesteelsmith.com. This column is for information only. Consult your health provider for medical advice.