Some prawns sampled from a section of the Logan River adjacent to the affected farms have tested positive, with further sampling and testing now required to determine if the disease has established in the Logan River.
The national Aquatic Consultative Committee on Emergency Animal Diseases, chaired by Australia's Chief Veterinary Officer, has met regularly since the first detection.
It agreed to a response plan that aims to eradicate the disease through nationally coordinated destruction, disposal and decontamination activities.
This work is well underway, with the Queensland Department of Agriculture and Fisheries (QDAF) leading the response.
Read about the first outbreak: