Two new cases of Hendra virus in equines have been identified by veterinarians in Queensland, Australia, and a Queensland horse has been euthanized with Hendra being confirmed as the cause.
Although the cases are miles apart and appear to be unrelated, the source appears to be fruit bats. A third case has been identified in New South Wales, but is not believed to be linked to the cases in Queensland.
The cluster of unrelated cases and the potential expansion of the range of this virus is of concern. Although the numbers are low, fatality rates among horses are high. Only a small number of human infections have been identified in the past, but those have all been in people working with sick horses and death rates are high.
This cluster raises concerns that it could be a bad season for Hendra virus, and re-inforces the need for people in endemic (and neighbouring areas) to take measures to reduce potential contact between fruit bats and horses.
In the New South Wales case, a fig tree in a paddock is thought to have been the source of bat exposure. Removing bat roosting sites from equine pastures is an important control measure.
A Hendra vaccine has been under development is Australia and encouraging preliminary findings were reported last year. Since this is a wildlife associated disease and complete avoidance of wildlife is impossible, vaccination may be a critical control tool to prevent both equine and, indirectly, human infections. Hopefully good progress with vaccine development continues to be made.