Horse Virus Spreading to Humans

Heads-up on new developments on a new disease. Australia's biggest outbreak yet of the highly virulent Hendra virus is underway. The disease is transmitted from fruit bats to horses and from horses to humans.

It was identified in 1994—the last year there was a major outbreak. One human trainer and 14 horses died then, reports the Sydney Morning Herald. A second infected person recovered.

Now changes in symptoms in Queensland horses are suggesting a new strain. Perhaps one capable of human-to-human transmission.

New Scientist reports that two veterinary workers became infected roughly four weeks ago and remain hospitalized. Fifty more people who may have had contact with horses will undergo a second set of tests.

So far this year at least seven horses are infected. Five have died. Thirty-six more will be tested for a second time tomorrow.

The classic symptom of Hendra virus in a horse is severely labored breathing, frothy nasal discharge and swollen muzzle. The animals often die within days.

But this year's horses are suffering from neurological symptoms, including paralysis and loss of balance.

Human symptoms include a severe flu-like illness, headache, high fever, and drowsiness, which can progress to pneumonia, convulsions, or coma.

The Hendra virus has not been identified outside of Australia. Every outbreak since the first has been successfully contained to only one horse. Between 1994 and now, one other person was infected and survived. Though, confusingly, the US Centers for Disease Control reports that two out of three human infections prior to this year were fatal.

Julia Whitty is Mother Jones' environmental correspondent, lecturer, and 2008 winner of the Kiriyama Prize and the John Burroughs Medal Award.