La Trobe University geneticist Dr Warwick Grant is one of only two Australians among 58 scientists world-wide recently awarded a $100,000 Grand Challenges Explorations grant from the Bill and Melinda Gates Foundation
With more than 120 million people at risk from a chronic debilitating parasitic disease called river blindness, his ground-breaking global health research focuses on a new method for evaluating the effectiveness and safety of drugs that might be able to eradicate this disease.
Dr Grant says currently there are no laboratory models with which to test new drugs against river blindness before they are used in clinical trials on humans.
He plans to develop one based on a parasite that infects an Australian bush rat found on the east coast near the Victorian and New South Wales border.
The parasite – spread by ticks and first described 30 years ago by a CSIRO scientist – causes a disease in rats very similar to river blindness in humans. Dr Grant will collect and transfer this parasite into laboratory rats.
Establishment of the parasite in the laboratory rat will create a model in which it will be possible to screen candidate drugs to replace ivermectin which has been used successfully in a mass distribution campaign initiated by the World Health Organisation over the past 25 years in Africa, preventing 40 million people from being infected with the parasitic worm that causes the disease.
Engagement with global partners
The announcement of Dr Grant’s win came on the eve of a visit to Australia in late June by leading philanthropist and Microsoft founder Bill Gates.
His foundation’s Grand Challenges Explorations project funds individuals worldwide to explore promising ideas that could help solve persistent global health and development problems.
Congratulating Dr Grant on his win, Vice-Chancellor Professor John Dewar said: ‘This research, funded by the Gates Foundation, is a wonderful example of La Trobe University engaging with global partners to make a difference in the world.’
Dr Grant says river blindness is caused by a parasitic nematode called Onchocerca volvulus which is transmitted by a tiny blood-sucking fly that bites humans.
The adult worms live more than 15 years in lumps under the skin and produce millions of baby worms that crawl around in people’s skin and eyes, causing skin disease and eventual blindness in many people.
‘Ivermectin prevents the disease by killing juvenile worms,’ he says, ‘but it does not kill adult worms, and many rounds of treatment with ivermectin treatment are required before adult worms eventually die of old age and transmission stops. The drug also cannot be used in areas where there is potential co-infection with other parasites.’
Growing concern about drug resistance
Dr Grant says it is crucial for the eventual eradication of the disease that new drugs are developed that can kill the adult worms while minimising side effects on humans, as existing treatments can sometimes prove fatal. The search for new drugs is also particularly urgent because of growing concern about the potential of resistance to ivermectin.
‘Without new drugs that can kill adult worms, multiple treatments with ivermectin need to keep working effectively for at least another ten to 15 years across the African continent to allow enough time for the current generation of adult worms to die and for parasite transmission to stop,’ Dr Grant says.
While initial Grand Challenges Explorations grants are valued at $100,000, successful projects have the opportunity to receive a follow-on grant of up to $1 million.
A plug for native parasites
Speaking to Fairfax Media science writer, Bridie Smith, Dr Grant said Australia was well known for its unique animals, but 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.
Watch Dr Grant speak on ‘The challenge of neglected diseases in the developing world’