September 9, 2005

Bats may have been source of SARS: study

WASHINGTON (Reuters) - Bats found in Hong Kong carry a
virus very similar to the severe acute respiratory syndrome or
SARS virus and might be able to spread it, Chinese researchers
reported on Friday.

They said the horseshoe bats, valued both as food and for
their use in Chinese medicine, should be handled with great
care. They may have helped spread the virus among different
species of animals, the researchers said.

SARS first emerged in China in 2002 and in 2003 spread
around the world via jet, killing more than 700 people and
infecting around 8,000.

It is caused by a new virus called SARS coronavirus.
Coronaviruses are common in people and animals and usually
cause nothing more serious than a cold.

But SARS was different.

"The isolation of SARS-coronavirus from caged animals,
including Himalayan palm civets and a raccoon dog, from wild
live markets in mainland China suggested that these animals are
the reservoir for the origin of the SARS epidemic," Kwok-yung
Yuen of the University of Hong Kong and colleagues wrote in
their report, published in the Proceedings of the national
Academy of Sciences.

"However, several lines of evidence suggested that the
civet may have served only as an amplification host for SARS
virus and provided the environment for major genetic variations
permitting efficient animal-to human and human-to-human
transmissions," they added.

So they studied wild animals in the Hong Kong countryside
that may have come into contact with civets.

They found a coronavirus similar to SARS in nearly 40
percent of wild Chinese horseshoe bats they examined.

Genetic analysis of the bat SARS virus showed it was
closely related to the human SARS coronavirus.

The researchers could not determine how the bats were
originally infected or whether bats were responsible for
transmitting the SARS coronavirus to other mammals including
the civets.

But because bat feces are used in Chinese traditional
medicine, and bat meat is considered a delicacy in parts of
Asia, the researchers suggest caution in handling them

"Interestingly, the nearest wildlife market previously
found to have animals with SARS in Shenzhen is only 10 miles
away from the locations with bats harboring bat-SARS in (Hong
Kong)," the researchers wrote.