Prawns were also sampled from a section of the Logan River adjacent to the affected farms and have tested positive.
Further sampling and testing is now required to determine if the disease has established in the river.
The affected farms are currently implementing destruction, disposal and decontamination activities to prevent the spread of the disease.
In other news, the current senior vice president of sales at Bumble Bee Foods has agreed to plead guilty for his role in a conspiracy to fix the prices of packaged seafood such as canned tuna sold in the US.
According to a one-count felony charge filed in the US District Court for the Northern District of California in San Francisco, Walter Scott Cameron and his co-conspirators agreed to fix the prices of packaged seafood from as early as 2011 until about 2013.
In addition to his guilty plea, which is subject to court approval, Mr Cameron has agreed to pay a criminal fine and cooperate with the division’s ongoing investigation.
“This charge is the first to be filed in the Antitrust Division’s ongoing investigation into price fixing among some of the largest suppliers of canned tuna and other packaged seafood,” said Acting Assistant Attorney General Renata Hesse of the Justice Department’s Antitrust Division.