Authorities fear yet another horse has died from the Hendra virus in southern Queensland.The horse fell ill and died at Park Ridge, south of Brisbane, on Monday night, not far from where other Hendra cases have been confirmed.Initial tests produced conflicting results. Results from further tests are due back later on Tuesday.The horse's owner and a vet who had contact with the animal have joined the list of people waiting to learn if they've contracted the potentially deadly virus.They now numbe

Authorities fear yet another horse has died from the Hendra virus in southern Queensland.

The horse fell ill and died at Park Ridge, south of Brisbane, on Monday night, not far from where other Hendra cases have been confirmed.

Initial tests produced conflicting results. Results from further tests are due back later on Tuesday.

The horse's owner and a vet who had contact with the animal have joined the list of people waiting to learn if they've contracted the potentially deadly virus.

They now number 17 in Queensland and nine in NSW.

Queensland's chief veterinary officer Rick Symons said there was only one horse on the Park Ridge property, which is now under quarantine.

"However there are horses on neighbouring properties so we are currently addressing the need to quarantine properties in the immediate area," he said.

Since June 20, five horses have died or have been put down after contracting Hendra - four in southern Queensland and one in northern NSW.

If Hendra is confirmed, the Park Ridge horse would be the sixth. Park Ridge is about 70km from Mt Alford and 50km from Kerry, where Hendra cases have been confirmed.

A total of six properties are now under quarantine - five in southern Queensland, including the Park Ridge site, and one at Wollongbar, in northern NSW.

Queensland's chief health officer Dr Jeannette Young said 17 people in the state were now undergoing tests for Hendra.

She revealed one is a Biosecurity Queensland vet who suffered a needle stick injury on the weekend, while responding to Hendra cases at Mt Alford in the state's south.

The vet, who was wearing double gloves and following procedure, went to hospital and she's being closely monitored, but is considered to be at low risk, Dr Young said.

Dr Symons said the recent cases in Queensland and NSW pointed to an increased Hendra risk for horses, but the cause was a mystery.

"Certainly something is happening out there and for some reason the chances of horses getting Hendra have increased," he said.

He said as many as five suspect horse samples a day were coming in for assessment from locations across Queensland.

"This reflects the heightened awareness among vets and horse owners about the ever-present danger of Hendra virus infection," he said.

He again urged vets to properly protect themselves when dealing with sick horses, and owners to take precautions.

"Fruit trees are flowering at the moment and there is a lot of flying fox activity," he said.

"Horse owners are reminded that they should not place feed or water under trees where flying foxes gather."

Flying foxes carry the Hendra virus, and can pass it to horses via their bodily fluids.

In a limited number of cases sick horses have infected people. Of the seven people have contracted the Hendra virus since 1994, four have died.