Monday, July 11, 2005
A Snip In Time.....
Circumcision may offer Africa AIDS hope
Procedure linked to much lower rate of new HIV
infections
- Sabin Russell, Chronicle Medical Writer
Wednesday, July 6, 2005
French and South African AIDS researchers have called
an early halt to a study of adult male circumcision to
reduce HIV infection after initial results reportedly
showed that men who had the procedure dramatically
lowered their risk of contracting the virus.
The study's preliminary results, disclosed Tuesday by
the Wall Street Journal, showed that circumcision
reduced the risk of contracting HIV by 70 percent -- a
level of protection far better than the 30 percent
risk reduction set as a target for an AIDS vaccine.
According to the newspaper account, the study under
way in Orange Farm township, South Africa, was stopped
because the results were so favorable. It was deemed
unethical to continue the trial after an early peek at
data showed that the uncircumcised men were so much
more likely to become infected.
All of the men in the study had been followed for a
year, and half the men had been followed for the full
21 months called for in the original study design,
according to the Wall Street Journal, which obtained a
draft copy of the study.
Begun in August 2002, the experiment is one of three
closely watched clinical trials in Africa to determine
whether there is scientific merit to nearly three
dozen less rigorously controlled studies showing that
circumcised men were much less likely to become
HIV-positive.
The hope is that, lacking a vaccine, the nearly 5
million new HIV infections occurring each year could
be slowed by circumcision, the surgical removal of the
foreskin -- a simple, low-cost and permanent medical
intervention that is a common but controversial
cultural practice in much of the world. In Africa,
about 70 percent of men are circumcised at birth or
during rite-of-passage ceremonies in early puberty.
Medical anthropologists began noticing as early as
1989 that the highest rates of HIV infection in Africa
were occurring in regions of the continent where the
predominant tribal or religious cultures did not
practice circumcision. Adult HIV infection rates above
30 percent are found in Zimbabwe, Botswana, Swaziland
and eastern South Africa, where circumcision is not
practiced; yet HIV infection rates remain below 5
percent in West Africa and other parts of the
continent where circumcision is commonplace.
Laboratory studies have found that the foreskin is
rich in white blood cells, which are favored targets
of HIV, the virus that causes AIDS. So the theory is
that men who are uncircumcised are much more likely to
contract the virus during sex with an infected woman,
and that the epidemic spreads when these newly
infected men have sex with other women within their
network of sexual partners.
The lead investigators of the study, Dr. Bertran
Auvert of the University of Paris and Adrian Puren of
South Africa's National Institute for Communicable
Diseases, are not talking. The results were expected
to be discussed at an AIDS conference in Rio de
Janeiro in three weeks. But word about the findings
has been circulating among researchers searching for
ways to slow the epidemic.
"I would be thrilled if it works, but we will also
need the results of other trials,'' said Johns Hopkins
University epidemiologist Ronald Gray, who is
conducting, in Uganda, one of two other controlled
clinical trials of male circumcision.
Gray's trial, which has completed enrollment of 5,000
men in the Rakai district of Uganda, is not scheduled
to end until 2007.
A third trial, under way in Kisumu, Kenya, is still
enrolling its quota of 2,700 volunteers and is also
expected to be completed in 2007, according to the
National Institute of Allergy and Infectious Diseases,
which is sponsoring it.
All three trials were designed to compare the HIV
infection rates of two groups of HIV-negative men,
one-half of whom would agree to be circumcised, the
other to be offered only counseling on AIDS
prevention. The studies were designed to show whether
or not circumcision provided a statistically
significant protective effect of at least 50 percent.
The South African study -- if the results are
confirmed -- suggests that the level of protection
afforded is even higher.
Although the apparent protective effect of
circumcision has been noted for more than 20 years,
doubts linger as to whether circumcision itself is
protective, or whether the lower risk may be the
result of cultural practices among those who
circumcise. HIV rates are low in Muslim communities,
for example, which practice male circumcision but also
engage in ritual washing before sex and frown on
promiscuity.
'nuff said!
