Some things are not welcome in Australia
An outbreak of foot and mouth disease (FMD) in Australia would devastate our livestock industries, costing anywhere between A$7-16 billion.
24 September 2012
Glen Paul: G’day, and welcome to CSIROpod, I’m Glen Paul. Foot and mouth disease, or FMD, is a highly contagious viral disease that affects all cloven hoofed animals, meaning those with divided hoofs, such as cattle, sheep, and pigs. While not usually fatal, it can permanently reduce the productivity of affected animals, and is economically devastating for livestock producers. An outbreak of foot and mouth disease in Australia would cost our livestock industry anywhere between seven and A$16 billion.
While there’s no treatment or cure, vaccines can protect against the disease, but don’t necessarily prevent animals from being infected. To assist in further enhancing Australia’s ability to respond to an outbreak Australia’s livestock industries and the Federal Government have invested in a five-year A$5 million research program to address vulnerabilities in Australia’s readiness to control Foot and Mouth Disease. The program will be managed by Animal Health Australia with the research carried out by CSIRO scientists from the Australian Animal Health Laboratory, working offshore to determine the level of protection Australia’s foot and mouth disease vaccine bank provides.
Joining me on the line is CSIRO’s Doctor Wilna Vosloo from the Australian Animal Health Laboratory. Wilna, just how infectious is FMD?
Dr Vosloo: Well it is actually seen as the most infectious animal disease known to mankind, and in the scientific world we also try and determine what we call the minimum infectious dose, and that is the number of virus particles that you actually need to infect an animal. And for some species, such as the impala, it’s been shown that as little as one virus particle can be sufficient to infect an animal.
So it’s really difficult if you have an outbreak, and especially if an outbreak is in pigs, because we see pigs as the amplifier host of the disease. So they excrete large amounts of virus, and of course this virus can be released into the atmosphere via their breath and their secretions, and hence they’re often seen as the source of an infection to other species.
Glen Paul: Hmm, so obviously one reason why you’d want to research offshore. Whereabouts are you doing the research?
Dr Vosloo: We are planning to do our research in various countries, because we are also trying to build relationships with different countries. Because Australia has not been able to work with a live virus, we are often slightly isolated in terms of our collaboration, so the project is also seen as an opportunity to build collaboration with other offshore facilities. So we have started our work in Vietnam, where we’re working with two facilities in the south of Vietnam, but we’re also planning to do some work in the United Kingdom, South Africa, and in Argentina.
Glen Paul: And as far as Australia is concerned, I believe the last possible FMD outbreaks occurred in the 19th Century, the last in 1872, so we’ve got a good track record. But the disease was able to breach the rigorous biosecurity measures of Japan and South Korea in recent times. How did the virus likely achieve that, and could it use a similar method to enter Australia?
Dr Vosloo: Well unfortunately the actual source of infection for both of those countries was never determined with certainty. So there are some ideas that it might have come in through hay or feedstuffs that were infected with foot and mouth disease virus, but it’s also possible that somebody did something illegal which nobody is actually aware of.
The foot and mouth disease epidemics follow sort of a sinus curve, and you do have times, some years, where there’s a lot of virus circulating in a lot of different countries, and during those periods the disease actually manages to then sort of escape from the source of infection and infect previously uninfected countries. So in 2010, and as well in 2001, this was the situation, where there was so much foot and mouth disease circulating, that it did spread into other countries.
Now, Australia is doing a lot to try and prevent the disease from coming into the country, but you’re always set with the uncertainty of somebody doing something illegal, and that of course can cause an outbreak.
Glen Paul: Now when you say illegal, does that mean somebody has deliberately bypassed a biosecurity measure in place?
Dr Vosloo: I guess the most famous idea is the fact that somebody brings in a sandwich with a piece of meat – ham or salami – that could carry the virus, because we know the virus can actually survive for a long period of time. The fear then is that this hypothetical sandwich can then get into the food chain, and that would mainly be through pigs, because if then fed to a pig, the pig becomes infected, amplifies the virus, excretes a lot of virus, and then becomes the source of infection for other species.
And of course you can imagine that that is rather very difficult to prevent at the airports, for instance. We do know that AQIS is doing an excellent job in educating people and trying to prevent this type of illegal action to happen.
Glen Paul: Hmm, yeah quarantine is very important. So what sort of findings have you turned up so far with your initial research in Vietnam?
Dr Vosloo: We have been able to only do one experiment so far, so we have actually taken one of the vaccine strains in the bank and vaccinated pigs with that, and then challenged them with a virus that is currently circulating in South East Asia. And we’re very happy to report that the vaccine performed incredibly well, and we’re happy to know that we’ll be able to tell the decision makers in that country that at least the one vaccine strain we have would be very worthwhile using, should we have an outbreak of the disease in that country.
Glen Paul: Sounds like you’re off to a good start. Just hypothetically, say there was an outbreak here in Australia, what would CSIRO’s role be in that?
Dr Vosloo: Our role would be diagnostics. So obviously if there is a clinical case that looks like foot and mouth disease, samples are taken and sent to the Australian Animal Health Lab here in Geelong, where we then test to see whether it is indeed foot and mouth disease virus. Now we receive those samples on a very regular basis because there’s group surveillance on the go in the field, and all of the cases the symptoms are not caused by foot and mouth disease.
And that is why the laboratory is also so incredibly important, because there are other diseases and circumstances, such as feed, that could cause lesions that look like foot and mouth disease. And because foot and mouth can have such an incredible economic impact, it’s of course important to know are we dealing with the real disease, or were these symptoms caused by something else?
Glen Paul: I see. Getting back to the project then, how long do you expect it to run?
Dr Vosloo: The project was initially set out for five years. We have done about two years of the project, so we still have three years to go, lots more exciting experiments to perform, lots more very exciting results to generate, so we’re really on the roll. Now that we’ve done the first one we’ve seen how it is to work overseas, because it’s always different from working at home, if you have to take your work, yourself, and your knowledge overseas, and it’s really been an excellent process. We can only comment on the absolutely fantastic collaboration we’ve had in Vietnam with our counterparts there, and it’s been a super process.
Glen Paul: Righteo. Well as I said, you’re off to a great start, and I look forward to checking in with you from time to time for an update on your progress.
Dr Vosloo: Thanks. And we’re really looking forward in sharing more with you in future.
Glen Paul: Doctor Wilna Vosloo. And to find out more about the research being undertaken at CSIRO, and to follow us on other social media, go to www.csiro.au.