The Courier & Advertiser (Angus and Dundee)
Giant rats used to sniff out disease in livestock
Scottish scientists are supporting a project which is training giant sniffer rats to detect a disease devastating livestock farmers in the world’s poorest countries.
Brucellosis is a highly contagious disease that causes infertility and low milk yields in cows, sheep, goats and pigs.
Humans can be infected, causing flu-like symptoms, problems in bones, joints and the heart, and in rare cases, death.
It is expensive and hard to detect, but now Glasgow University is working with researchers at Sokoine University of Agriculture in Tanzania on a project funded by the Foreign, Commonwealth & Development Office (FCDO) to use sniffer rats to tackle the problem.
African giant pouched rats, which can grow to 3ft in length, have already been successfully trained to sniff out landmines and tuberculosis.
Now the rodent disease detectives are being specially trained to help with the blight of brucellosis.
Professor Dan Haydon, director of the Institute of Biodiversity, Animal Health and Comparative Medicine at Glasgow University, said the idea came about after he discovered sniffer dogs were being used to detect brucellosis in the US.
He added: “I had been talking with someone who worked in Yellowstone National Park, where they have a brucella problem with elk, bison and cattle, and they use dogs to smell it.
“It was news to me. So, I was describing this somewhat light-heartedly to colleagues and Professor Rudovick Kazwala, who is lead researcher at Sokoine, said: ‘Aha, well, we already have this facility where rats are being specially trained to sniff landmines and tuberculosis’.
“So, we figured if they can smell landmines and smell TB, then surely we can get them to smell brucellosis? And the long and the short of it is that it turns out you can.”
He said the pandemic highlighted the importance of scientists increasing our understanding of how infectious diseases in animals can spread to humans.
“Six out of every 10 known infectious diseases of humans are estimated to originate from animals,” added Prof Haydon.
“Three-quarters of new or emerging infectious diseases in humans originate from animals, of which Covid-19 represents a particularly devastating example.”
The scientists received a grant to conduct the sniffer rat research through the Fcdo-supported Afrique One-aspire initiative.
Nine rats – named Hawking, Skinner, Sloth, Stewart, Zhang, Angela, Aung, Jane, and Pipp – are being trained to sniff out heat-inactivated brucella bacteria at the same lab in Tanzania that developed landmine and tuberculosis seeking rodents.
The brucellosis project is being supervised by Professor Kazwala and undertaken by masters student Raphael Mwampashi at Sokoine University.
Professor Kazwala, who completed a three-year PHD at the Moredun Research Institute in Edinburgh in 1996, said: “Rats have shown they were very effective in detecting landmines in projects rolled out in Angola and Mozambique, so we have moved on to disease detection.
“We had successfully trained rats to help diagnose tuberculosis and now we are using their incredible sense of smell to target brucellosis.
“The rats are conditioned over four to six months to sniff specimens. When a rat finds a positive sample, it hears a click and is rewarded. The rat learns that finding brucella means getting a food reward.”
Minister for Africa James Duddridge said: “The UK Government is proud to be supporting research that is not only protecting livestock – and farmers’ livelihoods – from debilitating diseases, but potentially increasing our understanding of how diseases mutate to make the leap from animals to humans.
“These Scottish scientists at the University of Glasgow are leading the way in using innovative ideas to detect diseases faster and at a fraction of the previous cost.”