WUNRN
HIV/AIDS - HIGH RATE OF AIDS IN
WOMEN OF AFRICA MAY BE DUE TO PARISITIC GENITAL DISEASE - RESEARCH
The disease
thought to contribute to AIDS in African women is caused by worms picked up in
infested river water. Credit Joao Silva/The New York Times
OTIMATI, South Africa — While around the world a
vast majority of AIDS
victims are men, Africa has long been the glaring exception: Nearly 60 percent are women.
And while there are many theories, no one has been able to prove one.
In a modest public health clinic behind a gas station here in South
Africa’s rural KwaZulu/Natal Province, a team of Norwegian infectious disease
specialists think they may have found a new explanation.
It is far too soon to say whether they are right. But even skeptics say the
explanation is biologically plausible. And if it is proved correct, a low-cost
solution has the potential to prevent thousands of infections every year.
The Norwegian team believes that African women are more vulnerable to
H.I.V. because of a chronic, undiagnosed parasitic disease: genital schistosomiasis (pronounced
shis-to-so-MY-a-sis), often nicknamed “schisto.”
The disease, also known as bilharzia
and snail fever, is caused
by parasitic worms picked up in infested river water. It is marked by fragile
sores in the far reaches of the vaginal canal that may serve as entry points
for H.I.V., the virus that causes AIDS. Dr. Eyrun F. Kjetland, who leads the
Otimati team, says that it is more common than syphilis
or herpes, which
can also open the way for H.I.V.
Also, the foreign bodies in the sores —
the worms and eggs — attract CD4 cells, the immune system’s sentinels, and
those are the very cells that H.I.V. attacks.
The worms can be killed by a drug that costs as little as 8 cents a pill.
Dr. Kjetland’s team is trying to determine whether that will heal the sores in
young women.
Some prominent AIDS experts doubt the schistosomiasis theory, pointing out,
for example, that urban women raised far from infested water also die of AIDS.
But proponents of the theory say that two decades ago, many experts were just
as skeptical of the idea that circumcision
protected men against H.I.V. It was not until 2006 that three clinical trials proved it correct.
Schistosomiasis “is arguably the most important
cofactor in Africa’s AIDS epidemic,” said Dr. Peter J. Hotez, dean of the
National School of Tropical Medicine at Baylor College of Medicine. “And it’s a
huge women’s health issue: Everyone has heard of genital mutilation and
obstetric fistulas. But mention this, and the headlights just go dim.”
The idea is slowly gaining ground. The Bill & Melinda Gates Foundation,
the United Nations, the National Institutes of Health, and the Danish and
Norwegian governments have all given some grant support. But leaders of the two
agencies that pay for the fight against global AIDS want more evidence before
diverting funds from their campaigns for condoms, drugs and
circumcision.
“We need to track all these things down and see what’s a cause and what’s
just another disease you have at the same time, like cervical
cancer,” said Dr. Mark R. Dybul, executive director of one of the agencies,
the Global Fund to Fight AIDS, Tuberculosis and Malaria.
Dr. Eric Goosby, who recently finished a five-year stint as coordinator of
the other agency, the President’s Emergency
Plan for AIDS Relief, or Pepfar, agreed that vaginal sores could help the
virus enter. “But it’s complicated,” he added. “A lot of women who have H.I.V.
don’t have schisto, and vice versa.”
From her small clinic just off the highway here,
Dr. Kjetland makes visits to high schools where she has government permission
to work because their communities have the highest rates of schistosomiasis. On
the dirt roads around these hills, it can take her hours to reach each one.
Through school nurses, she gives deworming drugs to all students, male and
female. (To her frustration, although the drug is sold by generic makers for as
little as eight cents a pill, South African patent laws permit only the Bayer
version, which costs $4.)
Then she meets with groups of girls ages 16 and up to ask the sexually
active ones to come to Otimati for gynecological exams and blood tests.
“I am as gentle as I can be, much more gentle than sex is for them,” she
said, “but even the slightest touch and they bleed.”
Gentleness is part of Dr. Kjetland’s nature. A 49-year-old stepmother of
five, she watches like a mother over the girls in her study. She ordered that
extra rooms be built where they can cry if they test positive for H.I.V. She
tries to make sure the boys in their schools never realize she chooses only
sexually active girls. And she has KFC delivered, since it is a treat for girls
who often have only cornmeal mush to eat for days on end.
Though trained in Norway, she has spent most of her life in Africa, growing
up in Tanzania as the eldest of a missionary couple’s six children, attending
prep school in South Africa, and, after college and medical school in Norway,
doing graduate work in Malawi and Zimbabwe.
An estimated 200 million Africans have had schistosomiasis. Although it is
rarely fatal, the bleeding it causes in children can lead to anemia, stunted
growth and learning problems. It is caused by tiny worms that live in
freshwater snails and emerge with pointed heads
that can penetrate the skin of people collecting water or washing clothes.
Once inside, the worms mate, with the female living in a cleft in the
male’s body “like a hot dog in a bun,” Dr. Kjetland said. Most nest in the
urinary tract — bloody
urine is the classic symptom — but a portion end up in the vagina, creating
“sandy patches” of damaged tissue and calcified eggs.
Studies by Dr. Kjetland in Zimbabwe and South Africa and by Dr. Jennifer A.
Downs of Weill Cornell Medical College in Tanzania have shown that women with
the patches are about three times as likely as their
neighbors to be infected with H.I.V.
A gold standard study to prove the connection would be both impractical and
unethical: Researchers would have to divide hundreds of infant girls into two
groups, give half deworming drugs and half placebos, wait until they were
perhaps 20 years old, and see how many had H.I.V. No ethics board would approve
placebos under those conditions.
So Dr. Kjetland studies teenagers, hoping to heal their sores and see if
their H.I.V. infection rates are lower than the norm. (In grown women, the
sores persist even after the worms die.)
For years, theories have abounded as to why African women become infected
with H.I.V.: for example, that they are more likely to have overlapping sexual
partners — not always by choice — while women elsewhere have boyfriends or
husbands in series. That rape, incest and domestic violence are rife in
southern Africa, where the AIDS epidemic is worst. That syphilis and herpes are
rampant. That impoverished, fatherless young women are forced to pay with sex
for food, clothes, grades and even car rides.
The schisto hypothesis can now be added to that list, but to some prominent
experts it remains unlikely.
One is Daniel Halperin, an epidemiologist now at the Ponce School of
Medicine and Health Sciences in Puerto Rico. He knows how it feels to be
doubted: In the 1990s, he was the chief proponent of the theory that
H.I.V.AdvertisementHe argues that tropical West Africa, where schisto is
common, has little H.I.V., while countries with little schisto, like arid
Botswana and mountainous Swaziland, have sky-high H.I.V. rates.
Dr. Salim Abdool Karim, a renowned South African AIDS researcher who
admires Dr. Kjetland’s work, is also skeptical. His team follows more than
1,000 women in an area only 40 miles from Otimati with equally high H.I.V.
rates.
“We’ve studied genital tracts in detail for 20 years, photographing them
sequentially,” he said, “and we see no sandy patches.”
Upon hearing that, Dr. Kjetland reached for the mounted magnifying scope
she uses to examine girls.
“They’re not looking in the right places,” she said.
Most gynecologists, she explained, are trained to look for cancer, which
usually starts near the center of the cervix, while sandy patches are tucked
away in crevices that can be seen only by swinging the scope to extreme angles.
It takes her weeks to train doctors to find them consistently, she said.
Fighting schisto across Africa would take an extensive pill-distribution
effort, but Dr. Hotez, the Baylor dean, argues that it is worth it.
Seventy million African children could be dewormed twice a year for 10
years at a cost of $112 million, he said in an
essay titled “Africa’s 32 Cents Solution for H.I.V./AIDS” (32 cents being
the cost of two generic deworming pills twice a year). That is cheap compared
with the $38 billion Pepfar is expected to spend on AIDS in that period, he
said.
A vaccine would be even better, and several are in development,
including one at the Sabin Vaccine Institute,
which Dr. Hotez also heads.
But even if one works, “it will be at least five to 10 years before the
testing is finished,” he said. “We shouldn’t wait for that.”