Feds Say 20 Million Have Form of HPV Virus*
Feb 27 4:42 PM US/Eastern
By LINDSEY TANNER
AP Medical Writer
CHICAGO (AP) -- One in four U.S. women ages 14 to 59 is infected with
the sexually transmitted virus that in some forms can cause cervical
cancer, according to the first broad national estimate.
The figure is mostly in line with previous assessments. The highest
prevalence _ nearly 45 percent _ was found in young women within the age
range recommended for a new virus-fighting vaccine, according to a
report from the federal Centers for Disease Control and Prevention.
Researchers have estimated that 20 million Americans have some form of
HPV. The study concluded that 26.8 percent of U.S. women are infected, a
figure that is comparable to earlier estimates using smaller groups.
"We expected the prevalence of any HPV infection would be high and
that's what we found," said CDC researcher Dr. Eileen Dunne, the study's
lead author.
Just 3.4 percent of the women studied had infections with one of the
four HPV strains that the new vaccine protects against. But that doesn't
mean the vaccine should be written off, said Dr. Yvonne Collins, an
assistant professor of gynecologic cancer at the University of Illinois
at Chicago.
For one thing, Collins said, that relatively small percentage
corresponds with a lot of women _ about 3 million, according to the
report. And it does not include those with past infections that have
cleared up.
The number of women with HPV strains targeted by the vaccine was lower
than in some previous, less comprehensive estimates. And the overall HPV
prevalence among the youngest women studied, 14- to-24-year-olds, was
substantially higher than in previous estimates, 7.5 million versus 4.6
million.
Dunne attributed those variations to different study populations and
different HPV detection methods. She said the results should not be
interpreted to mean infection prevalence has changed in recent years.
The new nationally representative report is based on vaginal swab
specimens from 1,921 women tested in 2003-04.
The report appears in Wednesday's Journal of the American Medical
Association.
There are dozens of strains of HPV. Low-risk forms can cause genital
warts and non-cancerous changes in cells in the cervix, and often clear
without treatment. Several high-risk forms have been linked with
cervical cancer.
Dunne said HPV prevalence is thought to be high in men as well, but none
were studied.
An estimated 11,150 U.S. women will be diagnosed this year with cervical
cancer, and about 3,670 will die from it. Numbers are much higher
worldwide, especially in developing countries where Pap tests to detect
cervical cancer are not routine.
The new vaccine, Merck's Gardasil, was approved last June for girls and
women aged 9 to 26. It protects against two HPV strains believed
responsible for about 70 percent of cervical cancer cases, and two other
strains that cause 90 percent of genital wart cases.
Other vaccines are in the works to protect against other HPV strains,
Collins said.
Women aged 20 to 24 had the highest overall HPV prevalence in the study,
44.8 percent. Prevalence increased each year from ages 14 to 24, then
dropped off gradually, confirming that young, sexually active women face
the greatest risk of infection.
The study underscores the need for young women to get vaccinated, and to
get routine Pap tests, said Dr. Howard Jones, a gynecologic cancer
specialist at Vanderbilt University.
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On the Net:
JAMA: http://jama.ama-assn.org
CDC: http://www.cdc.gov