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Operation in males fends off
three common viral STDs
By Nathan Seppa
Male circumcision offers a degree of
protection against genital herpes and
human papillomavirus infections, scientists report in the March 26 Ne w England
Journal of Medicine. Previous research
shows circumcision can also help protect against HIV, which means the operation can fend off the three most common
viral sexually transmitted diseases — all
of which are currently incurable.
The new findings, from a study of men
and adolescent boys in Uganda, show that
circumcision provides only partial protection against these three viruses, and
the researchers caution that it should
not be considered a full shield.
Nevertheless, that partial benefit could
have a huge public health impact, says
Anthony Fauci, director of the National
Institute of Allergy and Infectious Diseases in Bethesda, Md. Herpes ulcers, for
example, make a man more susceptible
to HIV infection. “Circumcision not only
prevents HIV outright, but also prevents
[genital herpes] that is associated with
an increased likelihood of acquisition of
HIV,” he says. In Kenya, four out of five
people infected with HIV are also infected
with genital herpes, says Robert Bailey of
the University of Illinois at Chicago.
Meanwhile, the new study and a recent
report from South Africa show that male
circumcision may benefit female sexual
partners, too. Compared with uncircumcised men, men who were circumcised as
part of either of the clinical trials were
one-third less likely to be infected with
one of the dangerous types of human papillomavirus, or HPV, that can cause cervical cancer when passed on to women.
A third study team, based in Kenya, will
also report findings in the coming months
on circumcision’s effect against STDs.
Bailey, a member of the Kenya study
team, could not give details but acknowledged that the upcoming results will fall
in line with the newly released data.
Earlier studies showed male circumcision lessened the risk of acquiring HIV by
up to 60 percent (SN: 10/29/05, p. 275).
“I think this trio of trials is certainly a
landmark in prevention, not only of HIV
but of these other sexually transmitted
infections,” says Judith Wasserheit of the
University of Washington and the Fred
Hutchinson Cancer Research Center,
both in Seattle. “These new data really
are a game changer.”
The trial in Uganda, supported by the
NIAID, the Bill & Melinda Gates Foundation and others, enrolled 3,393 uncircumcised heterosexual males ranging in
age from 15 to 49. None had genital herpes and all wanted to be circumcised.
Half were randomly assigned to get circumcised at the start of the trial, and the
others were designated to undergo the
operation after a two-year wait.
After the two years, circumcised volunteers were one-fourth less likely to have
genital herpes and one-third less apt to
carry a type of HPV that causes cervical
cancer, compared with the still-uncir-cumcised males. When all HPV types
were assessed, circumcised volunteers
were still nearly one-third less likely to
carry one of the types, says study coauthor
Thomas Quinn of NIAID and Johns Hopkins University in Baltimore. The study
did not show protection against syphilis.
Although male circumcision surgery
carries a slight risk of infection, the medical evidence showing long-term benefits
is now overwhelming, Quinn says.
The return of herpes
A single viral protein enables dormant herpes virus to wake up,
suggests a study published online March 27 in PLoS Pathogens.
The protein, called VP16, acts as the gatekeeper for viral activity,
new results in mice show. Figuring out what causes the shift from
an inactive to a highly infectious state is important for understanding the virus — which is carried by more than 70 percent of
the global population—and stopping its reappearance, says study
coauthor Nancy Sawtell of Cincinnati Children’s Hospital Medical
Center in Ohio. Infection with the herpes simplex virus usually triggers an acute phase that may be accompanied by a fever and cold
sores. The symptoms may subside, but the virus retreats and, in
people, hides in a cluster of nerve cells near each ear. Stress,
sunburns and fevers can rouse the latent virus (VP16 gene activity
shown in light blue). “If I can borrow a line from the diamond people, herpes is forever,” says Steven Triezenberg of the Van Andel
Institute in Grand Rapids, Mich. —Laura Sanders