As well as the more well-known signs of a fever and a new, continuous cough, individuals with the deadly bug could also develop bloodshot eyes as if they were having an allergic reaction.

Chelsey Earnest, a worker at the Life Care Center in Washington, told CNNthat for her, the eyes were “the single most important” sign patients had Covid-19.

She said: “It’s something that I witnessed in all of the patients.

“They have, like…allergy eyes. The white part of the eye is not red. It’s more like they have red eye shadow on the outside of their eyes.”

The NHS doesn’t list red eyes – or any eye issues – on its official list of symptoms.

They say the two main signs to look out for are a high temperature, meaning you feel hot to touch on your chest or back, and a new, continuous cough.