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Volume CXXXIII, Number 4 |
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Ask Dr. Jeff
JEFF BENSON, M.D.
Staff Writer
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 any STD as far as I know, and I'm feeling
pretty bad - and pretty worried - about all of this. What can you tell
me about genital warts?"
Dear Reader: Like all warts, genital warts are growths caused
by human papillomavirus (HPV). They are spread, almost always, through
sexual contact. Their incubation period is variable, ranging from a few
weeks to many months and even years. The vast majority of people infected
never develop any noticeable lesions. Available treatments for HPV do
not completely eliminate the virus, but for most people, infection is
probably transient and likely inconsequential. However, and by far most
importantly, some HPV infections are associated with serious long-term
effects. They may provoke cellular changes in the tissues of the cervix,
vagina, penis or anus. Over time, these changes may lead to cancer.
Genital HPV infections are among the most common STDs world
wide, with the highest rate of infection found in women under the age
of 25. It is estimated that up to 75 percent of college-aged people harbor
HPV virus. Probably only 1 percent of those infected have visible warts.
An additional 4 percent may be diagnosed by cellular changes found on
screening Pap tests.
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, 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 can look very much like normal "skin bumps".
More often, however, there are no lesions to be seen. The oncogenic role
of these two types of HPV is so prominent, that gynecologists sometimes
regard cervical cancer as a virtual STD. HPV 16 and 18 are found in over
99 percent of women with invasive cervical cancer.
HPV 16 and 18 are also strongly associated with anal and
rectal cancers, and regular screening anal pap tests are recommended for
those at risk (from unprotected anal sex.)
The clinical course of HPV infection can be significantly
affected by a number of factors. Immune function compromise (from certain
medications or HIV, for instance) usually results in higher viral loads,
more lesions, more rapid progression and oncogenic transformation of lesions,
and higher rates of viral transmission. Cigarette smoking has similar
effects.
There are no blood tests to detect HPV infection. The best
screening tests are Pap tests, both cervical, and if indicated, anal.
If these tests are positive, the infections can be treated, even if there
are no visible lesions.
Because of its long incubation period and the potential
presence of the virus without prior sexual activity, it's rarely possible
to determine the original source of infection. None of the types of HPV
which cause common warts on hands and feet can be spread to the genitals.
Like herpes, HPV does not survive long on inanimate objects and so cannot
be contracted, for instance, from toilet seats.
Safer sex practices remain essential to preventing transmission
of HPV. Consistent condom use is key. Regular check-ups and Pap tests
are equally important. Come on in to see us at the Health Center!
Jeff Benson, M.D.
Dudley Coe Health Center