Hendra death toll hits 13 for month

THE baffling Hendra virus has killed another horse in its seventh eruption this year in Queensland.

THE baffling Hendra virus has killed another horse in its seventh eruption this year in Queensland, even though the animal apparently survived a previous brush with it.

The outbreak is the second in the Logan area, on Brisbane's southern doorstep, and takes to 13 the number of horses that have died of the bat-borne virus since last month in Queensland and northern NSW.

Queensland chief vet Rick Symons said initial post-mortem tests had failed to detect the virus after the animal's death on June 28. Follow-up checks at the CSIRO's Australian Animal Health Laboratory detected antibodies to Hendra.

"This further testing showed the horse had extremely low levels of Hendra virus in its blood at the time it was sampled," Dr Symons said.

"This, together with the level of antibodies, suggests that the horse may have had a previous Hendra infection and had developed some antibodies."

The case will reinforce suspicion the virus can lie dormant in horses and people, then emerge long after the initial infection.

The second of its four known human victims, Mackay farmer Mark Preston, died in 1995, having relapsed 13 months after being infected while assisting in autopsies performed on infected horses. At that time, the Hendra risk was little understood. Three other people have survived infection.

Dr Symons said it was not known when the latest horse to die, on a property at Loganlea, just 25km from the Brisbane CBD, had contracted the virus. He said it was unusual for a horse to survive Hendra. "We just don't have any history of when it was infected," he said. "It could have been two weeks or a year ago."