The Australian Hendra horse virus is still causing concern since the initial outbreak in July as a female veterinarian who euthanised a racehorse infected with the potentially deadly virus is now being monitored in hospital after an accidental needle stick injury.
According to the Department of Primary Industries the vet was admitted to Brisbane's Princess Alexandra hospital last Friday and is currently being monitored for any Hendra-related symptoms at the hospital and waiting for the results of blood tests.
The horse, a thoroughbred, had recovered from the virus but was deemed a biosecurity threat and was the fifth horse to either die or be put down at a Brisbane clinic.
The vet is the third person to be hospitalised since the outbreak at the Redlands Veterinary Clinic, a male vet and a female vet nurse who worked at the clinic remain in hospital after being admitted last month after contracting the virus; both were involved in the autopsies of the infected horses.
The clinic remains under strict quarantine control and is at the centre of the worst outbreak of the virus since the death of horse trainer Vic Rail in 1994.
Tests conducted on more than 30 other horses at the clinic were apparently inconclusive and an investigation will be launched by workplace health and safety officers into how the needle stick injury occurred; Hendra is carried by native fruit bats and humans can contract it from infected horses.
Biosecurity Queensland chief veterinary officer Dr. Ron Glanville says blood tests on the horse had returned negative for Hendra virus, which was a hopeful sign for the vet who received the needle stick injury.
The horse Tamworth, was valued at $200,000 and was put down despite a fight to save its life.
Dr. Glanville says the affected horses appeared depressed, had poor appetite, fever, darkened mucous membranes, reduced gut sounds, colic, ataxia, regular lying down, trembling, head tilting, circling, loss of vision, aggression, and rapid deterioration and all died or were euthanised at the most after two days.
The first horse apparently had numerous neurological symptoms on admission, the second was reported to have had mild respiratory disease, and the third was reported as depressed on admission and collapsed the following afternoon, while the other two had pre-existing medical conditions.
Dr. Glanville says while efforts were made to ascertain the Hendra virus infection status of all the horses, samples were limited and some results inconclusive.
A horse who was a long-term resident at the clinic is suspected to have been the primary case as two weeks before its illness it was housed in yards overhung by trees where fruit bats are regularly seen.
The suspicion is that feed or water became contaminated after being exposed to the infectious body fluids of a fruit bat.
Research into the behaviour of the Hendra virus and how it jumps from bats to horses is ongoing.