Three horses tested positive for Hendra virus at a vet clinic on Brisbane's south-east outskirts on Monday, just over a week after the state was declared free of horse flu. One died, another is recovering and a third was put down. Biosecurity Queensland confirmed yesterday that the third horse was a racehorse.
Officials are testing 37 other horses, while the clinic is in quarantine to stop any possibility of the virus spreading. People who may have had contact with the horses are being contacted as the disease may be transmitted to humans, although that is rare.
Queensland Health is conducting blood tests on 25 clinic staff. Spokesman Brad McCall said the state's four recorded human cases - two of which were fatal - of Hendra virus infection came through close contact with sick horses. There was no evidence of human-to-human transmission, he said.
"We just don't know if this is a more aggressive strain of the virus that transmits more easily to humans. It's like nothing we've ever seen before," Redlands Veterinary Clinic owner Dr Lovell told the Courier Mail.
He said the symptoms shows by the horses were neurological, unlike the usual flu-like respiratory symptoms previously linked to Hendra. The new symptoms include aggression, loss of balance and facial paralysis.
Dr Lovell said there were 37 horses at the clinic, including racehorses, trotters and family pets, but his main concern was for his staff.
"I am particularly concerned for two or three people who were in closer contact with the infected horses than I was," he told the Courier Mail. "But Queensland Health has been very good and they've taken blood tests and provided us with counselling where needed."
In its first recorded outbreak in the world, the virus claimed the life of prominent trainer Vic Rail in 1994, along with 14 horses. It is named after the Brisbane suburb in which it was first discovered.
It is carried by fruit bats, but only rarely is transmitted to horses. This is the ninth recorded outbreak in Queensland, and by far the most serious since 1994. It follows a second human death in 1995 (of a farmer in close contact with sick horses), a dead horse near Cairns in 1999 and another near Townsville in 2004.
Biosecurity Queensland's chief veterinary office, Ron Glanville, said the virus should not be confused with equine influenza.
"There is no relationship between the two," he said. "I want to reassure Queensland horse owners and horse industries that we are not facing a lockdown situation or movement restrictions."
He was confident it would not spread through the horse population. "There is a quarantine, but it is only at the veterinary clinic where the sick horses were located," he said.
Racing officials expressed concern, but given veterinarian advice that it was much less likely to spread than EI, they were not panicking and were confident racing would not be affected.
Racing Queensland's chief operations manager, Malcolm Tuttle, issued a noticed to trainers which said: "Given recent advice, the outbreak is not expected to have any significant impact and should not pose any risk to the thoroughbred racing industry."
Queensland Premier Anna Bligh said the outbreak was being taken very seriously by authorities. "We will be thoroughly investigating all of the circumstances around this outbreak of Hendra virus," she said. "It's a very serious virus, and we need to make sure that if there have been any lapses in biosecurity that they are addressed immediately."
By Tim Dick with AAP / news agencies