Not just for breakfast any more ... flying foxes like this are now under health scrutiny
INTERNATIONAL concern over the origins of a 1999 nipah virus outbreak in Malaysia
has sparked a one-year epidemiological study of the virus carrying potential of Cambodian
James Olson, an epidemiologist/laboratory manager with the Global Emerging Infections
Surveillance Program and Cambodia's National Institute of Public Health, is leading
a study funded by the US Center for Disease Control (CDC) of the potential role of
flying foxes - famous for their roosts in the former UNTAC compound opposite Wat
Phnom in central Phnom Penh - in spreading the deadly nipah virus.
The Cambodian research is just one component of a regional study that includes Australia,
Indonesia, Malaysia and the Philippines.
"There's a hypothesis that 20 percent of [flying foxes] are chronically infected
with the nipah virus," Olson told the Post. "The reason why the flying
fox is interesting for research is that it's primarily urban."
According to Olson, the source of a nipah outbreak near the Malaysian city of Ipoh
in 1999 that killed 100 people was traced to pigs that had been infected with the
virus through contact with bat urine, feces and saliva.
Olson and his team are concentrating their research - which began in June and is
expected to conclude in mid-2001 - on the notorious "bat soup" restaurants
on National Route One in Kandal's Kien Svay District, at which approximately 300
flying foxes are butchered each week to prepared a medicinal soup that some Cambodians
believe improves night vision.
One of six blood samples taken from restaurant bats to date and sent for analysis
at CDC headquarters in the US has tested positive for nipah virus.
"We're now in the process of collecting data to see if [the positive nipah virus
sample] was one of six or one of a million [potentially infected flying foxes],"
He added that the people who collect the bats from the forest and who handle the
bats in the restaurants will all be tested for traces of exposure to the nipah virus.
While Olson emphasized that there is no medical evidence that anyone has every been
infected with nipah virus through contact with flying foxes nor consumption of their
blood or flesh, he agreed that close human contact with flying foxes at the Kien
Svay restaurants was a source of concern.
"The idea that there is contact between humans and bats makes you worry,"
he said. "I'll be relieved when we find out that restaurant workers and hunters
aren't at risk."
Joe Walston, a mammal specialist with the Phnom Penh office of the World Conservation
Society who is assisting Olson in his research, hopes that the CDC study will highlight
the threat posed to the flying fox species by the Cambodian taste for bat soup.
"One hundred years ago there were roosts of flying foxes fifteen kilometers
along the Mekong river; now we're just trying to find what's left, " Walston
said. "The Kien Svay restaurants kill approximately 15,000 bats a year and it's
clearly unsustainable ... the flying fox population of Prey Veng has been completely
cleaned out and hunters are constantly looking for new hunting areas."