One month ago a particularly virulent strain of African swine fever – which has been wreaking havoc in Asia since it was detected in China last year and could potentially kill up to 25% of the world’s pig population – landed on Australia’s doorstep.
The disease was detected just 680km north of Darwin, in Timor-Leste. Australian biosecurity agencies which had been screening major airports and mail distributors for illegally imported pork products redoubled their efforts.
Because while Australia’s border control and quarantine methods are strict, experts say pork products sent in the mail pose a risk. For example, a care package containing a pork product – some jerky, a cured sausage – is sent from a country where the disease is present to an Australian friend or relative. They eat the jerky and throw the packaging in the bin. It ends up in landfill where it is eaten by a feral pig.
The feral pig contracts the virus. There are 24m feral pigs in Australia. The virus spreads and enters the domestic pig population. Infected pigs either die rapidly or must be euthanised. And Australia becomes the next country in Asia declared a trade risk.
That scenario could happen, says the Australian Animal Health Laboratory’s deputy director, Debbie Eagles. The laboratory, a part of CSIRO, tested pork products seized at airports and from the mail system earlier this year and found a “reasonable proportion” carried the virus, which can be transmitted indirectly through packaging or clothing.
“If feral pigs were to come into contact with packaging that had held infected material, then it would be possible that transmission could occur in that way,” she says.
The virus can be destroyed by cooking or curing, but it depends on the method used. It is amazingly resilient to a variety of curing methods and environmental conditions. Any non-approved product from a host country poses a risk.
The consequences for Australia if the virus took hold are severe.
The local pork industry is worth $5.3bn, industry figures say, with 3,700 producers supporting 36,000 jobs.
Quarantine officials inspect a pig farm in Yeoncheon, South Korea. Photograph: Reuters
“Depending on the spread of diseases, you would have to start again from scratch,” the Australian Pork Industry’s chief executive, Margo Andrae, says.
What is African swine fever?
African swine fever virus is endemic to sub-Saharan Africa and was first described by western scientists in the early 1900s when European colonisers brought pigs into areas where the virus was present. A global effort to develop a vaccine has been under way since the 1950s when the virus jumped to Europe. The CSIRO is part of that effort.
It was first detected in China in August 2018. In January it was report in Mongolia; in February, Vietnam. Then Cambodia, Hong Kong, South Korea, North Korea, Laos, Myanmar and the Philippines.
Most recently – and Australia, worryingly – it was detected in the backyard pig population in Dili, Timor-Leste. A report filed to the World Organisation for Animal Health on 27 September said that 405 pigs died out of a potential 44,000 backyard and smallholder pigs in the Dili region. The extent of the outbreak is unknown.
Timor-Leste is Australia’s closest neighbour, and until recently biosecurity efforts had focused on major airports, not the broad expanse of the north.
African swine fever is a hemorrhagic fever. Symptoms include elevated temperatures, reduced appetite, vomiting, diarrhoea, black skin lesions or red blotchiness on the skin, nose and eye discharge, difficulty breathing, and convulsions. It can also cause sudden death. . It does not affect humans or other farm animals.
Among pigs, it spreads rapidly and kills in high numbers. Infected pigs, and any that may have come into contact with infected pigs, are euthanised.
A blood sample to test for African swine fever is taken in a backyard piggery in Quezon city, east of Manila, in the Philippines. Photograph: Rolex dela Peña/EPA
It has proved “exceptionally hard to control” in Asia, says Eagles. Rabobank, a global agribusiness finance company, predicts that China will lose between 20% and 70% of its herd – about 350m pigs, or 25% of the world’s total – by the end of the year.
“It’s a virus for which there is no cure and there is no vaccine so it’s a very difficult virus for countries to control or to eradicate,” she says. “The recent spread into Asia has certainly increased the risk for Australia.”
If the disease were to enter Australia, says Andrae, the mortality rate would be “huge”: “And that’s an animal welfare issue there that we’re just not willing to have on our doorstep.”
How could it get into Australia?
The most efficient method of transmission is pig-to-pig, usually through the exchange of bodily fluids. Australia has a longstanding ban on importing live pigs, pig genetic material and uncooked pig meat, all of which risk bringing in African swine fever, foot and mouth disease, and other pig diseases.
That ban is heavily enforced: two farmers in Western Australia were jailed in August for illegally importing Danish pig semen in shampoo bottles. In December a Brisbane company was fined $100,000 and its director $20,000 for importing uncooked pig meat which was considered a foot and mouth disease and swine fever risk.
Those laws mean the most likely way it would be introduced to Australia is illegally imported pig products that slip past Australian biosecurity controls because they were sent illegally by mail or not declared at the airport.
Passengers who provide false or misleading information about high-risk biosecurity items risk a $420 on-the-spot fine.
In the past six months Australian authorities have seized 27 tonnes of illegally imported pig products. If Australia remains swine fever-free, says Andrae, it will be a global advertisement for its biosecurity protocols.
The other risk is mud tracked in on shoes of travellers who walked in a farming area overseas, did not properly clean their boots before boarding a plane to Australia, and did not tick the box on the arrival form stating that they had visited a rural area.
The virus can survive for 36 days without a host and indefinitely in chilled or frozen products
Not ticking that box could save you 15 minutes when progressing through the arrivals hall, says Andrae, but it could also kill millions of pigs.
The virus can survive for 36 days without a host and indefinitely in chilled or frozen pork products. Discarded packages that once contained pork products could allow the virus to spread through the feral pig population.
The other risk is from backyard pigs. Swill feeding – allowing pigs to eat meat or table scraps that had come into contact with meat – is banned in Australia because it risks the spread of disease, but is still practised by some backyard pig owners.
“The industry is doing all the right things, making extra efforts in biosecurity,” says Andrae. But travellers, people sending packages, or people who have one or two pet pigs who don’t think they’re part of the industry pose a risk, she adds.
Eagles says the risk to Australia is “very high” but is confident it can be managed.
“Whilst we are certainly very concerned about the potential introduction of this virus we also have very good plans in place both for what we would do to prepare us as well as control it if it did get in,” she says.
Source link : https://www.theguardian.com/world/2019/oct/13/african-swine-fever-the-deadly-virus-at-australias-doorstep
Publish date : 2019-10-12 19:00:00