The risk of a serious livestock disease making its way to Australia is lower than authorities first expected, but cattle producers remain nervous about the threat.
Lumpy skin disease (LSD) was detected in Indonesia in early 2022, putting Australia's cattle industry on high alert.
It was estimated an outbreak of the disease would cost Australia $7.4 billion in its first year, from lost trading opportunities.
Despite the disease's spread throughout Indonesia, in particular on the island of Java, new modelling from epidemiology company Ausvet shows a reduced likelihood of an LSD incursion in Australia.
"An incursion appears to be much less likely than we previously thought," Ausvet director, Dr Brendan Cowled, told an industry webinar.
More than one insect required
In its research, Dr Cowled said Ausvet found it was unlikely for lumpy skin disease to spread to Australia via a single insect.
"Most of the research around the world shows that you need 30 to 50 insects to land on one single animal, and bite that animal about the same time, to start infection going," Dr Cowled said.
Modelling showed the risk of an LSD outbreak in Australia ranged between one in every five years, to one in every 14,652 years, depending on the amount of insects required for successful transmission.
"It shows it's not a very high likelihood of an outbreak if it takes quite a few insects to start an outbreak," Dr Cowled said.
"These insects have got to blow across in one little mob, all the way from Indonesia, they've got to land on one animal to start an infection."
Dr Cowled said the team expected the "truth" would be "an outbreak every few hundred years or every few thousand years".
However he noted the confidence intervals of the modelling was not high, with many questions left to be answered by science.
"There's quite a bit of uncertainty in our estimates," he said.
"That's because each one of those steps in that risk assessment path has some uncertainty where further science is required to refine this estimate."
'Take it with a grain of salt'
Kimberley pastoralist, David Stoate, was cautiously optimistic about the news.
He said the modelling sounded "encouraging", but hoped authorities would not become complacent.
"There are a whole lot of uncertainties to do with the modelling," Mr Stoate said.
"We need to take it with a bit of a grain of salt, and not relax the focus on biosecurity that the industry's had over the last few years."
The accuracy of cases in Indonesia concerned Mr Stoate, as well as uncertainties to do with how many vectors it would take to transmit the disease.
He said he hoped to see an increase in surveillance across northern Australia.
"The good thing that's happened over the last few years is that everyone's had a much greater focus on biosecurity, so we do need to keep that going," he said.
FMD modelling not released
Dr Cowled said surveillance efforts would continue, particularly in the Northern Territory which was the most likely path of entry for the disease.
"The Territory is really important ... the Kimberley is also important, and also the far north of Queensland if PNG or West Papua ever becomes infected," Dr Cowled said.
He urged "continued vigilance" for signs of the disease.
"We've still got to prepare as if an outbreak would happen," he said.
"Don't relax due to our research, just be alert but not alarmed."
Updated modelling on the risk of an incursion of foot and mouth disease has not been released.
However Department of Agriculture, Fisheries and Forestry's Dr Brant Smith said it was also likely the risk of an FMD incursion in Australia had reduced.
"You could say that it has decreased but to what extent, we don't have figures or numbers ... but it certainly has come down a bit," Dr Smith said.
