Buffer zones, strengthened by a vaccination programme, have proved effective in containing the disease.
Horses owners are looking forward to a gradual resumption of events and competitions from early next year, provided eradication efforts remain on track.
While the number of infected properties continues to grow, the number of properties where the virus is still considered active is dropping.
In Sydney, the Commission of Inquiry heard from Dr James Gilkerson, an expert in equine infectious diseases from Melbourne University, who gave detailed evidence on the nature of the virus and its means of transmission.
He told the Commissioner, retired High Court judge Ian Callinan, that the most likely cause of the outbreak was through people or equipment coming into contact with an infected horse, either at Sydney Airport or at the Eastern Creek Quarantine Centre.
The source of the outbreak, he said, was likely to be an infected horse with "subclinical" signs among the 52 taken into Eastern Creek between August 3 and 8.
The first horse to be confirmed with the disease was Encosta De Lago, a Coolmore stallion, although Dr Gilkerson said the animal was unlikely to have been the source of the outbreak.
He described procedures at Eastern Creek as inadequate. The virus, he said, can easily be destroyed through simple disinfection procedures and, with proper measures, it should have been contained at Eastern Creek.
It could have left the station to infect the wider horse population on contaminated materials, on vehicles used, or on people in contact with infected animals.
The Commissioner heard from several witnesses about quarantine procedures and was told how, four years before the outbreak, a senior quarantine vet had warned that better precautions were needed at Sydney Airport for the arrival of horses.