Bats may be part of Ebola solution as well as source of outbreak: scientist
A CSIRO research scientist says bats' immune systems could hold the key to fighting viruses like Ebola.
Bats are suspected of being the natural host for the Ebola virus.
Dr Michelle Baker says the animals are capable of carrying large loads of the virus without suffering so much as a fever.
"If you're a virus and your primary goal in life is to reproduce and survive, you don't necessarily want to kill your host really quickly, so bats and viruses have achieved a nice equilibrium," she said.
Bats live with Ebola by having certain components of their immune system constantly switched on so they are prepared before the virus enters their system.
"What we need to do now is learn how bats tolerate high levels of activation of the immune system, constantly, without any detrimental effects," Dr Baker said.
In contrast, the immune system of humans is only activated after contact with the virus.
Initially the virus shuts down the early response which then leads to a deadly overreaction.
"By the time our immune system is activated, the virus is already out of control," Dr Baker said.
"At this point, our immune system produces a huge pro-inflammatory response.
"The immune system's primary role is to destroy the virus but in the case of an infection such as Ebola, when the immune system is activated to a very high level, it's actually more damaging to the host than it is beneficial.
"A lot of the internal and external bleeding we see is actually a consequence of the immune system over-responding to the infection."
The way bats respond to viruses could provide a clue to successfully treating deadly infections like Ebola, but translating bat immunity into humans is also problematic because over-activation of the immune system can be so damaging.
"I think we've got a long way to go until we come up with a therapeutic we can translate from what we're learning from bats into humans."
Eating, butchering fruit bats causing Ebola transmission to humans
African fruit bats first pass the virus to primates and then to humans.
Dr Baker said transmission usually occurred through meat derived from a wild animal.
"A lot of the small villages in West Africa rely on bush meat as a primary form of protein in their diet," she said.
"So the primary risk factor is butchering and handling of the raw meat.
"We know that primates get very sick from Ebola virus so they may be acting as a secondary reservoir for Ebola."
CSIRO's Biosecurity Flagship director Dr Kurt Zuelke said the Ebola outbreaks and others like it, such as Hendra, Avian Influenza and SARS were the result of increased interaction between humans and wildlife.
"We see animals and people living in closer proximity as urban areas move into more rural areas," he said.
"Three quarters of the new diseases in people are coming from animals as we see increased mobility of people."
