According to The Sydney Morning Herald, veterinary professor Shane Raidal says that Australia's pig industry must be on alert to retain its disease-free status.

"The last thing we want is for our herd to become a reservoir of infection," Associate Professor Raidal, from Charles Sturt University, told AAP.

"Our pigs are healthy.

"Farmers need to prevent workers with fevers from having access to the pigs.

"They must be sent home and not let onto the farm."
,br> If Canada's disease-free status could be compromised so could Australia's, Professor Raidal said.

"Canadian pigs were susceptible, there was an outbreak there when a worker visited Mexico and then returned and the pigs started sneezing," he said.

But while farmers needed to worry about their pigs being infected, there was no cause for consumers to be concerned, because the infection did not survive meat processing, he said.