Third European Influenza Conference

[Guest guest]

Diseases pose big danger to biosecurity

Leigh Dayton, Science Writer | September 20, 2008

FORGET letters laced with anthrax spores and subway gas attacks: the

most serious biosecurity threat to Australia comes from economically

devastating diseases such as foot and mouth disease and Nipah virus,

as well as complacency about diseases such as bird flu.

The surprising risk assessment came this week in Sydney as a panel of

experts warned of risks to Australia's people, livestock and wildlife

from re-emerging and emerging infectious diseases (EIDs), mostly

originating in nearby South-East Asia.

" We (Australia) really are encased in a ring of fire to the north, "

said Daszak, executive director of the New York-based Consortium

for Conservation Medicine. " But the difficulty with this, for us, is

saying which is the next new disease. "

For instance, nobody saw severe acute respiratory syndrome coming.

Before SARS was identified in 2003 as a new and lethal disease, it had

been carried from China's southern Guangdong province to over 25

countries, ultimately killing nearly 900 people worldwide.

Fortunately, the " fortress Austalia " quarantine approach protected the

nation from SARS but it will be insufficient against future EIDs,

predicts veterinarian , who is with Murdoch University in

Western Australia and the Australian Biosecurity Co-operative Research

Centre.

" These viruses are actually on the move and Australia needs to

challenge itself as to whether it has the right (biosecurity)

procedures in place, " professor said. He recommends additional

financial and professional support to neighbouring nations with weak

surveillance and emergency response systems.

The panelists argue it is vital that biosecurity systems keep track of

diseases emerging in wildlife and livestock, as well as people.

That's so, says doctor Daszak, because more than 60 per cent of EIDs

are caused by animal pathogens and over 75 per cent of those spread

from wildlife. For instance, scientists believe SARS " jumped " to

people from wild animals collected for the lucrative exotic food trade.

Where animals and people are in close contact, chances increase that

an animal virus may develop the ability to infect people, or another

animal that can infect people. Eventually, SARS-like, it could spread

person-to-person.

Nipah virus is currently raising alarm bells. It jumped from bats to

pigs then from pigs to humans, in whom it causes encephalitis. The

virus is closely related to the Hendra virus which first emerged in

Queensland in 1994, killing 14 horses and their trainer. There have

been nine outbreaks since, the most recent hit a Queensland property

in July resulting in the death of a vet and horses.

The Malaysian Nipah virus outbreak led to 105 human deaths and the

culling of a million pigs.

" There are episodes of human-to-human transmission (of Nipah virus)

happening in Bangladesh right now, " said Daszak. " If an infected

traveller goes into (Australia's) agricultural area (it could spread

to pigs). One infected pig would cause millions of dollars in damage, "

he warned.

The economic impact of recent EID outbreaks ranges from over $US50

billion for the SARS pandemic, and nearly $US30 billion for foot and

mouth disease in the UK, to roughly $US400 million from the 1999

outbreak of Nepah virsus in Malaysia.

Public health expert Hall says the most famous EID is H5N1 avian

influenza, or bird flu. Only 245 people have died after contracting it

from chickens, but since it first emerged in 2003 medical experts have

feared H5N1 could develop the ability to be transmitted between

people. The result could be a global crisis akin to the 1918 Spanish

flu pandemic, says Hall, who is with the World Health Organisation's

Western Pacific Regional Office.

Hall's comments came as experts gathered this week in Portugal for the

Third European Influenza Conference.

Speaking to New Scientist magazine in advance of the meeting,

virologist Rob Webster of St Jude Children's Research Hospital in

Memphis, Tennessee, said: " It's doing what we knew it would do --

recombining and evolving. " Just two critical mutations would enable

the virus to infect people.

The conference heard that for the first time one of over 70 vaccines

being trialled had been shown to be effective against many strains of

H5N1, allowing nations to produce and stockpile it prior to an outbreak.

" The threat of a pandemic jumping from animals to humans is still

there, " said Hall, echoing the conference delegates' concern.

She warned local authorities against the belief that because H5N1 had

not yet gone global, it never would: " The number one threat is flu

fatigue. "

http://www.theaustralian.news.com.au/story/0,25197,24368211-23289,00.html