Pic: Jeff Camden Source: The Sunday Mail (Qld)
Hendra virus (originally Equine morbillivirus) was discovered in September 1994 when it caused the deaths of thirteen horses, and a trainer at a training complex in Hendra, a suburb of Brisbane in Queensland, Australia. The very first case, a horse that was housed with 19 other horses. The index animal died two days after becoming ill. All nineteen of the horses the index animal was housed with became ill, with 13 dying. The 7 horses that survived the virus were euthanised as a way of preventing relapsing infection and possible further transmission. Both the horse trainer,and a stable hand that were involved in nursing the original case fell ill within one week of the horse’s death. The stable hand recovered but the horse trainer died of respiratory and renal failure. The source of the virus transmission to humans was most likely frothy nasal discharge from the first sick horse.
Flying foxes (fruit bats) infected with the Hendra virus excrete the live virus in their urine, faeces and saliva for approximately one week from the start of the infection. They show no other signs of the infection. Symptoms of Hendra virus infection in humans may be respiratory, including hemorrhage and edema of the lungs, or encephalitic, resulting in meningitis. In horses, infection usually causes pulmonary edema, congestion and neurological signs.
After an outbreak on a property earlier this month and subsequent testing of the family and their animals for signs of the virus the family dog has now been found to be carrying antibodies to the potentially fatal bat-borne Hendra Disease. In what has already been a very bad Hendra season in Australia this new finding of the disease jumping to dogs has heightened the emergency that is already being faced there. Laboratory tests had shown cats, pigs and ferrets were capable of contracting and transmitting the virus but horses and people had been the only known casualties so far.
Queensland chief vet Rick Symons said: “This is the first time outside of a laboratory that an animal other than a flying fox or a horse or a human has been confirmed with Hendra virus infection.” The dog was not infectious but the presence of antibodies, picked up in routine screening after two horses died on the property showed it had been exposed. Dr Symons said it had probably been infected by the sick horses rather than by bats.
The dog’s owners, have two children, are reluctant to have the dog put down. It shows no sign of illness and is in quarantine but still on the property with their two other dogs.The policy when dealign with Hendra is to euthanize all animals found to have contracted the virus because it has the ability to become active again after a period of dormancy in the host. “Therefore leaving [the dog] alive is really putting people at risk,” Dr Symons said.
Queensland Premier Anna Bligh said the development was “very worrying”. She has convened an emergency meeting of biosecurity authorities today to review the advancing crisis. “We need to understand better what is happening with this disease,” Ms Bligh said.
The Premier said the Queensland government would continue to resist calls to cull flying foxes (fruit bats). This year’s Hendra season is the worst on record, with eight separate outbreaks fourteen horses have died from it or been put down and at least 90 are under quarantine at outbreak sites. Dozens of people are being monitored for symptoms as well.
Queensland chief health officer Jeannette Young said there was minimal infection risk from the dog to the family, who were continuing their infection-screening process. She said it was unknown whether dogs could transmit Hendra to humans but acknowledged that was “something we have to look at very carefully”. “This . . . has changed our knowledge very significantly,” she said. “It’s the first time that another species has been infected so we do need to work that through.”
Hendra has only been found in Australia and Whales however there is a very closely related disease called Nipahvirus which is carried by the same bat has been found in Malaysia, Singapore, Bangladesh.
Dog and cat owners are now being warned to keep their pets away from feeding bats in order to keep the outbreak from becoming even more serious. Vet Peter Reid, who helped in the first Hendra outbreak, advised owners to keep pets away from sick horses and consider removing fruit-bearing trees from their property in an effort to keep the fruit bats away.
For more information: http://www.theaustralian.com.au/news/nation/dogs-case-of-hendra-worsens-worries-over-spreading-virus/story-e6frg6nf-1226102334678
