The Australian outage has proven sufficiently serious that the NSW government has launched an investigation into how the infection occurred and what can be done to prevent it happening again.
According to the AAP newswire, Australia's health minister Carmell Tebbutt was alerted over the weekend, but officials were at pains to stress that no lives were placed at risk.
The opposition health spokeswoman, Jillian Skinner, jumped on the problem, saying there has been a complete failure of the computer-aided dispatch system that allows ambulances to respond to patients.
As of Monday morning local time, three of the four computerised control systems were operational, following an outage lasting more than 24 hours.
Earlier, Mike Willis, the general manager for NSW ambulance operations, was quoted by the newswire as saying that, until technicians were sure the virus had been removed, the back-up system would continue to be used.
'It's important to note that at no time during that shutdown procedure were any [emergency] calls or in fact the integrity of our operation, breached", he said.