The 'Grand Princess' cruise ship docked in Adelaide on Monday morning following an 18-day round trip to Queensland and back.
It is unclear how many people on board were affected by the double outbreak, but the ship has capacity for 2600 passengers and 1150 crew members.
Passengers have began to disembark the ship and South Australian premier Peter Malinauskas said those on board needing urgent care would be transported to hospital facilities in a way that was safe.
"It's been something we've been monitoring pretty closely over the last 48 hours," Mr Malinauskas told Nine's Today show on Monday.
"The good news is reports that we've got from the cruise operators that the number of cases presenting has actually dramatically decreased over the course of the last couple of days."
In a statement, SA Health confirmed the ship docked in Melbourne on Saturday to undergo a clean, and all passengers disembarked while that was undertaken.
"We have been in contact with the ship's doctor this morning," the statement said.
"SA Health has been informed that the outbreaks have been declared over and the few remaining cases are consistent with numbers you would expect on any cruise."
Cruise operator, Princess Cruises has been contacted for comment.
10°C