© REUTERS/Andrew Kelly

The flu and the new coronavirus have similar symptoms, but the latter is far deadlier.

Here's how the two diseases' death rates compare among various age groups in the US.

The coronavirus is five to 10 times more deadly than the flu for those between the ages of 0 and 45. It is 12.5% more deadly than the flu for those over 85.

Research from the Centers for Disease Control and Prevention reveals how much more deadly the coronavirus is than the seasonal flu in the US.

Many people have compared the flu and COVID-19, the disease caused by the coronavirus, because both can affect the respiratory system and their symptoms overlap. Even President Donald Trump recently said of the coronavirus: "You can call it a germ, a flu, a virus, you can call it many things."

But the most crucial difference between the flu and the coronavirus is that the latter is far deadlier.

Whereas about 0.1% of people who get the flu die, the coronavirus' global death rate is now at about 4.7%, based on the current numbers of cases and deaths. However, the death rate of the coronavirus fluctuates constantly and varies strongly by country - in Italy, it was above 11% as of Monday, while in the US it was 1.8%.

Death rates of both the flu and the coronavirus vary widely among age groups - both seem to be most fatal in people over 65 years old.

© Shayanne Gal/Business Insider

As the comparison above shows, the coronavirus is more fatal than the flu across all age ranges, but especially among older people. That aligns with data from nearly every country with high numbers of coronavirus cases. The virus also more seriously affects people who have preexisting health problems.

Outbreaks among elderly populations in the US have proven especially tragic. Because the coronavirus spreads via droplets when people are in close contact and is deadliest for people over 80, nursing homes can be dangerous breeding grounds. An outbreak in the Life Care Center in Kirkland, Washington, killed 37 of the 120 people living there, according to Democracy Now.

Many states, including Washington, Mississippi, and New York, have banned visitors from nursing and retirement homes.

During the 2018-19 flu season, about 35 million people in the US contracted the flu and about 34,000 died, according to the CDC. The agency estimates the total number of flu infections in the US via its influenza surveillance system, which gathers flu data from state and local partners, then projects nationwide totals using infectious-disease models.

During the 2018-19 season, about one out of every 1,000 people who got the flu died.

However, breaking down the numbers by age range reveals a more complex story. Among children, there was about one death in every 10,000 cases. In adults between 50 and 64, about six out of every 10,000 people who got the flu died. For people 65 and older, the rate rose to about 83 out of 10,000.

The flu's death rate varies depending on the strains circulating each year. The flu virus also mutates rapidly, so people can get infected by different strains, which is why the vaccine isn't 100% effective and why new vaccines are developed every year.

In the US, the coronavirus has infected more than 153,000 people since the first case was reported on January 22. But that number likely far undercounts the true scope of patients, since it represents only those who have gotten tested, and the US has been slow to expand testing capacity. People with symptoms mild enough to recover at home without seeking medical treatment aren't counted in the official totals.

Even in New York, which has done the most testing per capita and has the US's highest case total and death toll, few people with non-critical cases are being tested.

"Unless you are hospitalized and a diagnosis will impact your care, you will not be tested," New York City's health department says.

The coronavirus' death rate changes as more cases are confirmed. Many health experts believe that the rate could drop if more mild and asymptomatic cases are tested.

The flu and the coronavirus spread in the same way: via viral particles that travel between people in tiny droplets of saliva or mucus. If a sick person sneezes, coughs, or eats within 3 to 5 feet of someone healthy, the particles could land on the healthy person; if the particles enter the person's eyes, nose, or mouth, the person can become infected.

An average coronavirus patient infects 2-2.5 others. That makes COVID-19 more contagious than the seasonal flu.

That's the reason so many countries are restricting residents' movement to encourage social distancing. Three-quarters f the US population has been told to stay at home.

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