Hendra Virus Threatens Australian HorsesBy Kentucky Equine Research Staff · November 14, 2011
Hendra virus is transmitted from large fruit bats to horses, and then from horses to humans. No cases of bat-to-human transmission have been recorded. National guidelines require euthanasia for affected horses.
An outbreak in 1994 was the first recorded incidence of the disease in Australia. Affected horses showed severe respiratory distress and death within 36 hours of the onset of disease signs. Since that time, the virus has been reported in 63 horses, one dog, and seven humans, four of whom died from the virus.
Disease signs in the 2008 outbreak were chiefly neurologic and included depression, loss of appetite, and incoordination in five horses. Human deaths were also reported from this outbreak.
In 2011, more than 20 horses were diagnosed with Hendra virus. Despite several theories, no one knows the reason for the spike in cases. Monitoring of the fruit bat populations in eastern Australia has shown an increase in the amount of virus that is shed, and research is in progress to find out more about the disease.
A protective equine vaccine has been developed, and it is hoped that the vaccine will be commercially available in 2012. No human vaccine exists.