TORONTO -- As confirmed cases of the coronavirus now exceed 400 in China, one medical expert suggests it is not yet time for Canadians to panic.

Officials in China reported late Tuesday that they鈥檝e now confirmed 440 cases of the coronavirus, with nine deaths. Since the illness was first discovered, airports across the globe, including several in Canada, have begun implementing check points in an attempt to contain the disease.

鈥淚 think there鈥檚 a good chance that it might be a bit of an overreaction,鈥 Dr. Michael Curry, a clinical associate professor at the University of British Columbia鈥檚 Department of Emergency Medicine, told CTVNews.ca in a phone interview. 鈥淲e鈥檝e all had a coronavirus in our past -- probably about 10 per cent of common colds are caused by coronaviruses.鈥

Coronaviruses are a large family of viruses, which includes severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and other viruses that are known to cause the common cold.

The newly discovered virus can cause coughing, fever, breathing difficulty and pneumonia.

鈥淭his particular coronavirus does seem nastier than most, but preliminary data shows it鈥檚 not quite as bad MERS or the SARS coronavirus,鈥 Curry said.

On Tuesday, the U.S. reported its first case of the coronavirus. There have been no such cases in Canada.

Canada鈥檚 chief public health officer has previously said there is no reason for panic as the risk to Canadians remains low.

Right not, the bigger concern in Canada is the influenza virus, which shows has sent 802 Canadians to hospital and has killed 13 people so far this flu season.

In the U.S., that so far there have been at least 120,000 influenza-related hospitalizations and 6,600 deaths linked to the flu.

鈥淲e get very blasé about the flu because people think that they have the flu on a regular basis,鈥 Curry said. 鈥淭he death rate seems low, which is good news, but you multiply that by a population of eight billion and all of the sudden you start getting some really big numbers.鈥

While nine people in China have already been killed by the coronavirus, Curry notes that these new viruses often appear worse than they really are, in part because the full extent of those infected is not yet known.

For example, Curry explains that the swine flu in Mexico appeared to be extremely deadly during an outbreak in 2009, but it was only because the reports were only among the sickest people.

鈥淚 suspect that that pattern is going to play itself out here in China that it鈥檚 the really sick people that are being tested,鈥 he said. 鈥淭here鈥檚 probably a lot more people than 300 people with it -- like a lot more, a couple of zeros more -- but most of those people have relatively mild illnesses.鈥

When it comes to the airport screening measures, Curry said we won鈥檛 know how effective they鈥檒l be until after the outbreak, but he鈥檚 skeptical.

鈥淭he hallmark of the airport screenings is about fever detection and self-reporting of symptoms,鈥 he said. 鈥淧eople, generally after a long flight, they don鈥檛 want to be held up at an airport and face a quarantine. Self-reporting rates are going to be a lot less than 100 per cent.鈥

Curry also notes that with similar infections, patients are infectious long before they have any symptoms of the illness, which limits the effectiveness of the airport checks.