Dear Dr. Jeff: My ex-girlfriend told me she was diagnosed with genital warts, and that she needed to be treated to prevent cancer. She was a virgin when we met, which means she must have gotten them from me. I've never had an STD as far as I know, and I'm feeling bad, and pretty worried, about all of this. C. L.
Dear C.L.: Like all warts, genital warts are caused by the human papillomavirus (HPV). HPV is spread, almost always, through intimate physical contact. Its incubation period is variable, ranging from a few weeks to many months and even years.
None of the types of HPV that cause common warts on hands and feet can be spread to the genitals. Like the herpes virus, HPV does not survive long on inanimate objects, and so cannot be contracted, for instance, from toilet seats.
Genital HPV infections are among the most common STD's world wide, with the highest rate of infection found in women under the age of 25. In this country, it is estimated that 75 percent of sexually active people contract HPV at one time or another, and that at any given point in time, 20 million Americans have genital HPV infections that can be transmitted to others. Every year, over 5.5 million people become infected. These are HUGE numbers!
Probably only one percent of those infected have visible warts. An additional four percent may be diagnosed by cellular changes found on screening Pap tests. Most fortunately, a great majority of HPV infections are overcome by our immune systems and resolve without further complications.
Over 100 types of HPV have been identified, about 30 of which cause infection of genital mucosal sites. Viral DNA is incorporated into infected cells, and often remains unnoticed by the host's immune system.
Two of these types cause very noticeable, though painless, "cauliflower-like" growths. They are usually treated topically, with medications or cryotherapy (freezing), with the aim of removing the lesions and also stimulating an immune response to the infection.
Two other types of HPV, numbers 16 and 18, cause the cellular changes that can be pre-cancerous. They sometimes cause small, flat growths to appear, which look very much like normal "skin bumps". More often, however, they cause no visible lesions at all. HPV 16 and 18 are found in over 99 percent of women with invasive cervical cancer.
They are also strongly associated with anal and rectal cancers, and that's the reason regular screening anal pap tests are recommended for men and women who have unprotected anal sex.
There are no blood tests to detect HPV infection. If pap tests are positive, the infection can be treated, even if no lesions are visible.
Cancer of the cervix and rectum are among the more treatable and preventable cancers. Microinvasive carcinoma of the cervix and anus are nearly always curable surgically. More importantly, both have a prolonged pre-clinical phase permitting early detection and treatment.
All too many women newly diagnosed with invasive cervical cancer have never had a Pap smear, and many others have not had one in the previous five years. Cervical cancer may indeed be an HPV-related "STD," as the OB-GYN's like to say, but, more importantly, it is a disease of medical neglect. The same is very much the case for anal cancer.
Because HPV can infect genital areas not covered by condoms, condoms do not provide complete protection against the spread of HPV. The protection they do provide, however, is especially important because it stops the spread of cervical, anal and other internal infections.
Condoms, of course, also offer very effective protection against the spread of HIV, chlamydia, and other STD's, and offer reasonably effective protection (about 85 percent) against unwanted pregnancies as well.
So: come on in to the Health Center and get your Paps (cervical and anal), and use those condoms! Always!
Jeff Benson, M.D.
Dudley Coe Health Center