Bush rats carry a parasite long overlooked by scientists.When Bill and Melinda Gates put out the call for a suitable animal to test drugs for the debilitating river blindness disease, geneticist Warwick Grant knew he had just the thing.
Enter the Australian bush rat. Common in heathland areas of Victoria and NSW, the bush rat carries a parasite long overlooked by scientists.
First described 30 years ago by CSIRO scientist David Spratt, the parasite is found only in Australia, but produces the same symptoms in the bush rat that the chronic river blindness disease triggers in humans.
So Dr Grant wrote to the Bill and Melinda Gates Foundation and secured a $100,000 research grant – one of only two Australians and 58 scientists worldwide to do so this year.
It will pay for Dr Grant and colleagues from his La Trobe University to collect parasite-carrying ticks from NSW bush rats trapped near Batemans Bay and place the ticks on laboratory rats.
The lab rat, which hails from the same family as the bush rat, then becomes an animal model on which to screen candidate drugs to replace the human treatment used by the World Health Organisation to prevent infection.
If successful, it will be the first time researchers have had an animal model on which to test the new drugs for the debilitating disease, which affects more than 37 million people in Africa.
”For most human diseases there are experiments in animals prior to clinical trials in humans,” Dr Grant said. ”That’s not possible for river blindness because there is no animal model available.”
The search for a suitable animal to study is growing increasingly urgent. While the drug Ivermectin has been successfully used for the past 25 years, it is not ideal. It does not kill the parasite and needs to be taken annually for up to 25 years.
The preventative drug, essentially the same drug given to dogs to prevent heart worm, has been around for more than two decades and there is growing concern the parasite will develop resistance.
”Eventually this drug will fail, so new drugs are desperately needed,” Dr Grant said.
River blindness affects mainly poor, rural African communities. Symptoms include permanent blindness, rashes, lesions and intense itching. It is caused by a parasitic worm that enters the body via the bite of a blood-sucking fly. Adult worms live under the skin for more than 15 years and produce millions of larvae that crawl around in people’s skin end eyes.
Dr Grant said while Australia was well known for its unique animals, the rare parasites those animals host were less appreciated.
”Our wildlife has evolved in isolation for a long time, so it follows that there is a lot of novelty in Australian parasites,” he said.
This story Administrator ready to work first appeared on Nanjing Night Net.