October 25, 2005

Biodiversity may help slow disease spread-experts

By Alister Doyle, Environment Correspondent

OSLO (Reuters) - Better protection for the diversity of the
planet's creatures and plants could help shield humans from
diseases like AIDS, Ebola or bird flu and save billions of
dollars in health care costs, researchers said on Tuesday.

They said human disruptions to biodiversity -- from roads
through the Amazon jungle to deforestation in remote parts of
Africa -- had made people more exposed to new diseases that
originate in wildlife.

"Biodiversity not only stores the promise of new medical
treatments and cures, it buffers humans from organisms and
agents that cause disease," scientists from the Diversitas
international group said in a statement.

"Preventing emerging diseases through biodiversity
conservation is far more cost effective than developing
vaccines to combat them later," it said ahead of a November
9-10 conference of 700 biodiversity experts in Oaxaca, Mexico.

Peter Daszak, a scientist who helped find links between
Asian bats and the SARS virus, said the 2003 outbreak of the
flu-like disease cost about $50 billion, largely because it cut
travel and trade from Asia. About 800 people died.

And AIDS, widely believed to have originated in
chimpanzees, killed an estimated 3.1 million people in 2004 and
the United Nations estimates that $15 billion will be needed
for prevention, treatment and care in 2006 alone.

"Emerging diseases are causing a crisis of public health,"
Daszak, executive director of the consortium for conservation
medicine at the Wildlife Trust, New York, told Reuters.


Diversitas experts urged governments to work out policies
to protect biodiversity, including tougher regulations on
trade, agriculture and travel to reduce chances that diseases
like avian flu can jump from wildlife to people.

"We're not saying that we should lock up nature and throw
away the key," said Charles Perrings, a biodiversity expert at
Arizona State University. But he said humans should be more
careful about disrupting areas of rich biodiversity.

He said diseases had spread from wildlife to humans
throughout history but the risks were rising because of the
impact of growing human populations on habitats.

The experts said the preservation of a wider range of
species could also ease the impact of disease.

A factor helping the spread of Lyme disease in the eastern
United States, for instance, was the absence of former
predators like wolves or wild cats that once kept down numbers
of white-footed mice -- a reservoir of the infection.

Lyme disease was also less of a problem for humans in U.S.
states where the ticks that transmit the disease had more
potential targets, like lizards or small mammals.

"The value of services provided by nature and its diversity
is under-appreciated until they stop," said Anne Larigauderie,
executive director of Paris-based Diversitas, a non-government

She said China had to employ people in some regions to
pollinate apple orchards because the over-use of pesticides had
killed off bees. "It maybe takes 10 people to do the work of
two beehives," she told Reuters.

And the Australian gastric brooding frog had once been seen
as key for anti-ulcer drugs because it bizarrely incubated its
young in its stomach after shutting off digestive acids. It has
since become extinct, taking its secrets with it.