In what might appear to be an outrageous attention-seeking exercise, scientists from the University of Glasgow say it’s “entirely possible” giant rats could be trained to sniff out COVID-19.

Except it’s true.

There are already COVID-sniffer training programs for dogs in airports  in at least half a dozen countries, including Australia.

According to an SBS report, the dogs are “taught to recognise a specific odour in sweat samples and the aim is to use them alongside required PCR testing for international passengers.”

The dogs will reportedly go to work in Australian airports early this year.

A Finnish program already in train at Helsinki airport claims faster and more accurate results in picking up asymptomatic infections using dogs rather than standard medical testing.

In at least half a dozen countries, the COVID-sniffing program could be expanded into hospitals and sports venues.

So why giant rats when we can have cute beagles?

Giant African pouched rats, up to a metre long, have been used with great success for 20 years to sniff out landmines and tuberculosis in low-to-middle income countries.

The giant rats, nocturnal burrowing natives of sub-Saharan Africa, are pests in the wild and sometimes hunted and eaten, according to a report from the United Nations Interregional Crime and Justice Research Institute.

But they’re very smart, quick to learn and blessed with highly sensitive nostrils to navigate burrows through the dark.

It takes 250 days to train them to sniff out landmines – three times less than the time required to train mine-detection dogs.

Better at detecting tuberculosis than the lab

A 2018 study found that the giant rats were able to detect when a child has tuberculosis (TB), and were “much more successful at doing this than a commonly used basic microscopy test.”

In Tanzania, Mozambique and Ethiopia, sniffer rats have helped increase the detection rate of tuberculosis in clinics by around 40 per cent.

Now, African and Glasgow researchers in Tanzania, as part of the Afrique One-ASPIRE initiative, are investigating the potential for sniffer rats to detect brucellosis in cattle.

According to a statement from the University of Glasgow:

• Brucellosis is a highly contagious zoonotic disease that infects livestock species such as cattle, sheep and goats, causing abortion, infertility and low milk yields.
• Humans can contract brucellosis through direct contact with livestock or from drinking unpasteurised milk.
• Though rarely fatal in humans, it is a debilitating disease that also causes devastating losses to the livestock industry and small-scale farmers in some of the world’s poorest countries.
• Currently, diagnostics for both humans and animals have several constraints, meaning brucellosis is grossly under-reported and under-diagnosed, resulting in its status as a neglected tropical disease.
• Using the same methodology employed when training rats to detect tuberculosis, the aim of this project is to prove the rats’ suitability for detecting Brucella in livestock dung –  and then, if successful, deploy the rats as highly effective additional diagnostic tools, particularly in settings where there are large number of samples to be analysed and resources are limited.

So where is the COVID-19 angle?

It was in this context that Professor Dan Haydon, director of the Institute of Biodiversity, Animal health and comparative medicine at the University of Glasgow said the rats could conceivably be used in the fight against COVID-19.

“It is entirely possible that these rats could be trained to detect COVID-19. There is already evidence that dogs can,” he said in a statement.

And that’s the angle that got picked up by news media. Along the way, the African story got a look-in too.