The novel coronavirus, which originated in the Chinese city of Wuhan and has now spread to 12 countries, has much in common with seasonal flu. They are both viral infections, share similar symptoms and - crucially - can spread from human to human. In the midst of flu season in much of the northern hemisphere, telling the difference between the two will be vital in stopping its spread.
Human coronaviruses, of which there are four, can cause respiratory infections similar to flu: while many symptoms are mild, both can lead to pneumonia and become lethal. However, the novel coronavirus is more serious than a "typical influenza infection," says Ian Jones, a professor of virology at the University of Reading.
"This virus appears to go further down into the lungs than would generally be the case, therefore giving you symptoms of pneumonia: the lungs becoming flooded, they don't function very well and the patient gets into breathing difficulty."
Why is it more feared than the flu?
While the mortality rates and symptoms of flu and novel coronavirus may end up being similar, humans' ability to fight off the viruses differ greatly.
Humans have naturally built up antibodies to seasonal flu and scientists have developed annual vaccines to fight it. During a pandemic, which the new coronavirus has the potential to become, "there is no immunity in the population so you have potential for a global spread," warns Jones.
There is also a widespread familiarity with flu, which dampens concern. As with the Ebola epidemic and the Zika virus, both of which peaked in the middle of the last decade, fears around the new coronavirus are compounded due to a lack of knowledge over its nature.
Flu can spread from person to person from up to six feet away, largely caused by liquid emitted when the inflicted cough or sneeze. Those infected are usually contagious for around three days following the beginning of their illness, although this time-frame could stretch to over a week.
All this and more remains a mystery in regards to the new coronavirus. To understand the virility of the outbreak, Jones urges a focus on whether or not international cases lead to secondary infections. "If they don't," he explains, "it would suggest that the virus doesn't transmit quite so well: clearly all the people on the airplane (that traveled from an infected zone) didn't get it."
Medical advice is similar across those countries with confirmed cases of the infection. In France, authorities are asking those who think they are infected to call an ambulance rather than visiting a hospital, where they could potentially pass on the virus. Similar advice has been issued in China and Germany.