高清福利片

Foot-and-mouth disease 鈥� usually referred to by its acronym FMD 鈥� is the most feared livestock disease in the world. It can cripple the livestock sector, cause immense animal suffering, destroy farmer businesses, create food insecurity and has massive trade impacts for Australia.

It鈥檚 little wonder Australian farmers, rural communities, consumers and governments have reacted to the incursion and spread of FMD through Indonesia with dread.

This high-impact livestock disease has not been on our doorstep听. Keeping it out is a new challenge and a national priority.

This disease is caused by a viral infection. It鈥檚 present in many areas of southeast Asia, and most recently in Indonesia, where it has so far spread eastwards to Bali. Papua New Guinea, Australia and the South Pacific are听.

What makes FMD virus so remarkable is its听. It can persist on many inanimate objects, such as equipment used with livestock, people鈥檚 clothing and shoes, on the tyres of vehicles and in livestock transport.

It can also persist in livestock feed and livestock products, such as meat and hides. It can even remain infectious on the hands and within noses of those in contact with infected livestock.

This means everything associated with infected livestock can become contaminated. On the positive side, FMD is not a disease that readily infects humans, and meat and milk from infected livestock are considered听.

Still, despite human safety, countries free of FMD would not buy Australian meat or milk if we became infected because of the fear of importing the disease.

The nature of this virus is what scares agricultural industries. FMD virus could plausibly be introduced via a tourist鈥檚 contaminated shoes, or through smuggled meat products in a passenger鈥檚 bag or the mail. There is a plethora of incursion pathways.

FMD affects cloven-hoofed animals, such as cattle, sheep, goats, pigs and deer. FMD is one of the most听听known 鈥� it鈥檚 at least as contagious as the Omicron variant of COVID-19 in some situations, for example.

The characteristic sign in FMD infected animals is blisters. These are apparent in the mouths and hooves of infected animals 鈥� especially in the soft tissue immediately above the hoof, and between the two toes that form the hoof.

Rupture of these blisters produce ulcers. FMD lesions are very painful: animals stop walking, stop eating and drool. The severity of signs vary with different strains of FMD virus and different species.

Another remarkable characteristic is that within an infected herd or flock, nearly all animals become infected and sick, yet few will die from the disease in normal circumstances. It is a high morbidity, low mortality disease with a massive economic impact.

FMD is globally distributed and globally feared. Infected countries are isolated from the global livestock trade.

There are a large number of FMD听. This is important because one measure to prevent economic and welfare impacts is to vaccinate susceptible livestock.

However, the vaccine needs to match closely with the strain in a region that is causing FMD. Also, the protection period is generally short-lived, perhaps 12 months or less.

Maintaining high levels of vaccination and herd immunity is challenging in livestock populations, especially in developing countries. It requires an advanced system of livestock identification, and advanced vaccine manufacture and delivery infrastructure.

Another problem is the host range of FMD. Besides managed livestock, in Australia FMD virus could infect feral pigs, feral goats and wild deer.

Once the infection enters these unmanaged populations, disease control becomes exponentially more difficult.

For example, we haven鈥檛 been able to successfully manage听, despite the massive damage they inflict to our environment, such as degrading our waterways and threatening native species.

If Australia鈥檚 feral population gets infected, it might mean we can never eradicate FMD, should an incursion occur.

When responding to an FMD incursion in developed countries such as Australia, the goal is eradication. Based on the economic impacts of the disease, it鈥檚 less costly in the long run to eradicate than to live with the disease.

Perhaps the best example of such a response is when FMD entered the United Kingdom in 2001. How it entered is unknown, but听听is the virus entered from illegally imported infected meat fed to Northumberland pigs.

There was a delay in detection. By the time authorities recognised the problem, the infection had spread widely. The response involved identifying both infected premises and those likely to be infected because of possible contact with the virus, and then culling all livestock on those premises.

听the UK鈥檚 agriculture and tourism sectors, resulted in the death of more than 6.5 million livestock and cost 拢8 billion. The听听presented images of apocalyptic bonfires of burning carcasses and soldiers digging mass graves.

Even if a country demonstrates that elimination has been successful, it still won鈥檛 be able to trade again for many months, as its trading partners respond. This is why it鈥檚 so important to get on top of any incursion听.

The closest analogy to an FMD response we鈥檙e familiar with is the incursion of听听(鈥渉orse flu鈥�) in New South Wales and Queensland in 2007.

Although culling isn鈥檛 part of the response for to equine influenza, the bans on horse movements and equine events, the mobilisation of a large veterinary workforce, and the creation of disease 鈥渮ones鈥� would be repeated, with the same disruptive effect on communities.

To Australia鈥檚 advantage, because FMD is such a high profile and high impact disease, federal, state and territory governments have well-developed听听and have 鈥渨ar-gamed鈥� FMD scenarios over many decades.

And more recently, other animal pest and disease incursions such as varroa mite听听and Japanese encephalitis听听have helped test our response systems for an FMD incursion.

However, we shouldn鈥檛 underestimate the cost and challenge of confronting this disease that has arrived just this month on our doorstep. So much depends on it.

This piece is written by Professor Michael Ward from the University of Sydney School of Veterinary Science and the Sydney Southeast Asia Centre and was originally published in .听

Hero image: Adobe Stock.