Seven horses have died and more than 30 people are now playing a waiting game to see whether they have contracted the deadly Hendra virus.
That, however, is the growing reality for Australians living in the parts of Australia known to be at risk from the Hendra virus.
Seven cases have been diagnosed in little over a fortnight. In all, 31 people now face a six-week wait and regular testing to determine whether they have the deadly infection.
It is, by any measure, a bad start to the Hendra season, which coincides with the breeding season of flying foxes – the native fruit bats that provide a reservoir for the virus.
It has been suggested that disruption to normal feeding grounds resulting from devastating floods in the region earlier this year may be in some way be responsible for the surge in cases.
The virus is able to be passed on to horses, and is then capable of jumping to humans. Of the seven known cases of human infection, four have proved fatal.
While the risk of people contracting the virus is considered low – victims have all had major exposure to bodily fluids from sick horses – the reality is that horse owners need to ramp up their biosecurity in areas considered prone.
While flying foxes are the natural hosts for Hendra virus, at certain times of the year – particularly around the breeding season for the bats – there is an increase in the number of cases in horses.
Scientists believe horses most likely catch it through exposure to the bats’ feces, urine and/or birth cleanings.
Exactly why the virus is able to infect people once it has infected horses is not fully understood.
The virus can cause a range of clinical signs and should be considered where there is acute onset, fever and rapid progression to death associated with either respiratory or neurological signs.
Most cases in horses are fatal but, occasionally, a horse will survive the infection. The reported mortality rate in affected horses is greater than 70 per cent, but regulations require all infected horses to be euthanized.
The brightest hope is in the development of a vaccine. There is also an anti-viral treatment that is offered to those considered to have had high exposure to the virus. To date, no instances of high exposure have been reported in the latest spate of cases.
The Hendra and related Nipah virus are given the same respect in laboratories as the Ebola Virus and Marburg Haemorrhagic Fever Virus.
Australian scientists from the Commonwealth Scientific and Industrial Research Organization announced in May that a new experimental vaccine helped to protect horses against the deadly Hendra virus.
Read more at http://www.horsetalk.co.nz/health/179-hendra.shtml