From contradicting his own public health officials on the coronavirus to dismissing the World Health Organization's global fatality rate of COVID-19 as "false", US President Donald Trump has been accused of attempting to downplay the seriousness of the disease since the virus reached the US earlier this year.

The accusations continued on Monday when Trump tweeted: "So last year 37,000 Americans died from the common Flu. It averages between 27,000 and 70,000 per year. Nothing is shut down, life & the economy go on. At this moment there are 546 confirmed cases of CoronaVirus, with 22 deaths. Think about that!"

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The tweet came as US stocks plummeted over fears of the virus. Trump is set to meet his administration's economic officials later on Monday to discuss the fallout from the virus.

The president's comparison of the two viral illnesses underscores a larger misunderstanding of the implications of the new coronavirus, which has spread to at least 34 states, and how it compares with better understood seasonal outbreaks, according to public health experts.

So last year 37,000 Americans died from the common Flu. It averages between 27,000 and 70,000 per year. Nothing is shut down, life & the economy go on. At this moment there are 546 confirmed cases of CoronaVirus, with 22 deaths. Think about that! — Donald J. Trump (@realDonaldTrump) March 9, 2020

While both viral illnesses have comparable symptoms, including fever, fatigue, and a dry cough, and while they both spread through respiratory droplets, the outbreaks should be viewed and approached very differently, said Dr Leana Wen, an emergency physician and public health professor at George Washington University in the US.

"It is true, that at the moment, any individual in the US is more likely to contract the flu than contract coronavirus," said Wen, who is also the former health commissioner for the city of Baltimore, "but this is essentially a pandemic that is spreading around the world."

She added: "You cannot compare the impact or the potential effect of this [coronavirus] to the flu, because this is a new virus that is spreading around the world that does not have a vaccine or treatment".

Unknown trajectory

Many variables currently remain unknown about the coronavirus - and those mean it warrants greater precaution than existing seasonal outbreaks, Wen said.

"The major difference is that the new coronavirus is exactly that: it's new. We have no idea yet about the trajectory of the disease, how severe it's going to be, and how much it will spread," she said.

As of Monday, COVID-19, the disease caused by the coronavirus, had infected more than 100,000 people in at least 105 countries and territories across the world, with more than 3,800 deaths.

In the US, at least eight states had declared a state of emergency over the coronavirus as of Monday, with at least 423 confirmed cases and 19 deaths, according to the Centers for Disease Control and Prevention (CDC). A running tally maintained by John Hopkins University put the number of confirmed cases at 565 and the number of deaths at 22.

No vaccine or treatment

The virus that causes the flu infected between 34 million and 49 million Americans from October 1, 2019, to February 29, 2020, according to CDC data. However, the currently available vaccine, combined with treatment for those who do contract the disease, helps to contain the spread and fatality rate, Wen said.

There is no vaccine or established treatment protocol for the coronavirus.

"When you think about how we stop the spread of a disease, prevention is key, and treatment is very important, too," said Wen. "It will take at least a year, and up to a year and a half, to develop [a coronavirus vaccine]. While trials for treatment are in progress, we do not yet have a treatment for it either."

Death rate

Trump's comments also ring hollow when you look at the death rates of the coronavirus and flu, Wen said.

During the last flu season, between 20,000 and 52,000 people died from influenza in the US, according to the CDC.

According to the most recent data worldwide, "the [COVID-19] death rate appears to be far greater than the flu", Wen said.

"It appears that out of 1,000 people who have this coronavirus, somewhere between 10 to 30 people will die, compared to one person [out of 1,000] who has the flu," she said.