kingdragonfly: Let's do this here.
How Dogs Are Sniffing Out Covid-19
It's not just the elusive vaccine that will defeat Covid-19, scientists are looking at all sorts of methods to contain the pandemic. One of the more unusual could be in recruiting man's best friend. Scientists at the London School of Hygiene and Tropical Medicine believe that they can train dogs with a particularly keen sense of smell to diagnose people with the illness, even if they are displaying no symptoms.
This is really interesting - but with a proviso that the dogs can smell signs of infection, but not specifically C-19 - so the detection could be from some other viral flu/cold-like illness.
However, the alternatives (ie for airport screening for fever, pre-flight PCR tests etc) aren't good enough to be of much use. People can take antipyretics (paracetamol, NSAIDS) if they've got a fever to evade screening (this isn't hypothetical - they do it on purpose, anything to avoid missing a flight) and anyway fever isn't always present with C-19, nor if fever is present is it always corresponding to when the person is infective. PCR testing may be a gold standard, but with a high false negative rate, and too slow to get results (or faster but with low testing capacity).
But anyway, if you're sick with a fever then you shouldn't be getting on a plane (or going to other high-risk of transmission places) regardless of what's making you sick.
Whether people will be happy to be screened by this method is another question. "Sorry - the dog says you're not getting on the plane" is not like ie drug/food smuggling and quickly resolved by checking luggage etc, and it's pretty clear that there are a significant number of people who just don't give a damn about spreading C19.