Bats under surveillance for Hendra clues

Scientists are monitoring bat activity on a southeast Queensland property where the latest Hendra virus outbreak occurred.


Biosecurity Queensland scientists are using infra-red cameras to film horses, bats and other wildlife at night at a Tewantin property, where a horse contracted Hendra, to see how the virus is transmitted to horses.

Bats are known to carry the virus but it's unclear how the virus is transmitted to horses.

It's a crucial link in the chain which could lead to preventative measures to stop horse to human transmissions.


Four of the seven people who contracted the virus from infected horses have died since the disease first emerged in 1994.

In the latest case, the infected horse was put down last week and 11 people who came into contact with it face a long wait before they can be cleared of the potentially fatal virus.

Biosecurity Queensland started monitoring bat activity on the property last week.

Research leader Dr Hume Field said so far bats had not been captured on camera, as bat activity on the property had since declined.

"We're trying to understand the specifics of what happens that allows the horse to become infected," Dr Field said.

"When flying foxes feed they often chew the fruit up, take the juice out and drop the rest on the ground but we don't know if this happens under a tree horses stand under and if the horses sniff at or eat this stuff.

"Also, do the bats come down to horse food bins and water troughs and is there a risk of contamination that way?"

Dr Field said using infra-red, time-lapse photography to monitor bats and horses interaction has been in the pipeline for six months after the technique proved successful in Bangladesh.

He said Bangladesh researchers used infra-red cameras to discover how the lethal Nipah virus, a relative of the Hendra virus, jumped from bats to humans.

"One of the modes of transmission of Nipah virus is from date palm where the sap of the trees is collected and sold to people as a drink," Dr Field said.

"To collect the sap they put an open pot underneath a cut and the sap trickles down into the pot and they were able to capture on film the bats licking at the cut in the tree and sometimes they were licking from the pots as well."

Dr Field said the saliva from infected bats was contaminating the juice consumed by people.

Since this discovery, pots and cuts on the trees are now covered, preventing contact with infected bats, he said.

The Queensland study will also observe any other nocturnal wildlife, such as possums, that interact with horses in case another animal may also be involved with the transmission of the disease.

The 12-month project is currently at the Tewantin property but may be moved to other areas in southeast Queensland

PETRINA BERRY
Brisbanetimes.com.au