Queensland Horse Euthanized after Contracting Bat Lyssavirus

Biosecurity Queensland has quarantined a property on the Southern Downs—located in southeastern Queensland, Australia, near the border of New South Wales—after a horse tested positive to Australian bat lyssavirus (ABLV). This is the first known case of ABLV identified in a horse.

Chief Biosecurity officer Jim Thompson, BVSc, MACVSc, said the horse was euthanized on May 11 after falling ill.

“It tested negative for hendra virus infection but further testing returned a positive result for ABLV,” he said. “Another horse showing similar symptoms was euthanized at the same property five days earlier.

“There are 20 other horses on the property,” Thompson continued. “The vet involved in both cases used PPE (personal protective equipment) and took appropriate precautions. The site will remain under quarantine while further testing is conducted on the remaining horses.”

ABLV is carried by bats and flying foxes, he noted.

Staff from the Darling Downs Hospital and Health Service Public Health Unit will visit this property to assess the situation and identify any human potentially exposed to this horse. The public health staff will interview all people identified as having been in contact with the horse to determine whether any post-exposure treatment is required.

Queensland's Chief Health Officer Jeannette Young, MB, BS, FRACMA, FFPH, said it is important to remember that human cases of lyssavirus are incredibly rare.

“There have only been three recorded cases in Australia, all in Queensland, and sadly, all three people passed away,” Young said. “All three cases were the result of direct exposure to bats with lyssavirus.

“This is the first case where Australian bat lyssavirus has been identified in a horse, although we know from overseas that horses can be infected with rabies,” she said.

“There is a theoretical possibility that transmission to humans could occur,” Young continued. “We do however have a preventative treatment that is effective in any person not displaying symptoms of the virus. Warwick and Toowoomba hospitals will provide a free course of this preventative treatment to anyone who public health staff determine was in close contact with this dead horse resulting in a risk of exposure to the virus. Simply patting a horse would not constitute exposure.”

People who have had a potential exposure to ABLV require an injection of rabies immunoglobulin and a series of four rabies vaccine injections. Anyone with a weakened immune system will require a further (fifth) dose of vaccine and follow up blood tests to confirm their immunity. This course of treatment is also known as post-exposure prophylaxis.

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