It’s Friday afternoon and we’re sweating on another Hendra virus rule-out. These things always seem to happen on Friday afternoon, and this one sounds like it could definitely be Hendra. The result comes in and, once again, like it is 99 times out of 100, it’s negative. Thank goodness!

Ninety-nine out of 100–yes, those are the odds. At Biosecurity Queensland we currently test samples from around 200 suspect Hendra cases per year, and over the past few years we’ve only had two positive new cases each year. This is out of a horse population in the at-risk areas that has been estimated at about 200,000.

If Hendra infection in horses is very rare, then why is there so much concern? In terms of diseases that kill horses, it is way down the list, and similarly for diseases that kill people.

I suppose the answer lies in the fact that statistics can only tell part of the story. Many people in Queensland have a very close relationship with their horse. There is no other disease I’m aware of that you can catch from your horse and it can kill you (aside from rabies, and Australia is currently rabies-free); Hendra’s case fatality rate in people to date is higher than 50%