The coronavirus' estimated fatality rate appears to have risen to 3.4%, but experts think it could drop again

STR/AFP/Getty ImagesAn exhibition centre converted into a hospital in Wuhan, China, on February 5, 2020.

The coronavirus outbreak that started in December has killed more than 3,000 people.

Nearly 93,000 people have gotten sick across 77 countries, though 87% of cases are in China. (For the latest case total and death toll, see Business Insider’s live updates here.)

The new disease, called COVID-19, has a fatality rate of around 3.4%, the World Health Organisation (WHO) confirmed on Tuesday. That’s an uptick from previous estimates – a recent study from the Chinese Centre for Disease Control and Prevention found a fatality rate of 2.3% among more than 44,000 confirmed coronavirus patients.

The fatality rate is still changing as more cases are confirmed, however. Some health experts predict that it could decrease as the number of cases rises, since the people who are checking into hospitals have the most severe symptoms.

“There’s another whole cohort that is either asymptomatic or minimally symptomatic,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in a February 6 briefing. “We’re going to see a diminution in the overall death rate.”

The real fatality rate could be lower

The coronavirus’ fatality rate looks different depending on how you slice it. Most of the cases so far are in China’s Hubei province. The fatality rate there is slightly higher than the global figure: around 4%.

The Chinese CDC found that patients ages 80 and older have a much higher fatality rate than the rest of the population: nearly 15%. Patients with at least one other chronic disease, in addition to COVID-19, had a fatality rate of 10.5%.

But many unknowns remain, since many patients are still being treated in hospitals and new cases are reported daily.

Hospital wuhanSTR/AFP/Getty ImagesMedical staff set up beds as they prepare to accept patients displaying mild symptoms of novel coronavirus infection in Wuhan on February 5, 2020.

The virus also continues to spread in countries outside of China, including South Korea, Italy, and Iran. The number of new cases reported beyond China now exceeds the number of new cases reported in China, where the outbreak appears to be tapering off.

A peer-reviewed study published in The Lancet estimated that an infected person could pass the virus to two to three others, on average.

But not all severely infected patients die, of course. About half of the critical patients in the Chinese CDC study survived.

The majority of people who’ve died were elderly or had other preexisting health issues

So far, COVID-19 is far less deadly than SARS, which is also a coronavirus and had a fatality rate of 9.6% during the 2002-2003 outbreak.

Fauci said the coronavirus could wind up looking more like a pandemic flu than like SARS in terms of its fatality rate. SARS and the new coronavirus share around 80% of their genetic codes, but the coronavirus family also includes pneumonia and the common cold.

The worst pandemic flu, the 1918 Spanish influenza, had about the same fatality rate as the coronavirus right now. Other pandemic flues have been less deadly, Fauci said, with fatality rates between 0.8% and 1.2%.

The normal seasonal flu, he added, has a fatality rate of around 0.1%. This year’s strain is even less deadly so far, with a fatality rate of 0.05%, according to the CDC.

French lab scientists in hazmat gear inserting liquid in test tube manipulate potentially infected patient samples at Pasteur Institute in Paris, Thursday, Feb. 6, 2020. Scientists at the Pasteur Institute developed and shared a quick test for the new virus that is spreading worldwide, and are using genetic information about the coronavirus to develop a potential vaccine and treatments. (AP Photo/Francois Mori)Associated PressFrench lab scientists manipulate samples from patients potentially infected with the novel coronavirus at Pasteur Institute in Paris on February 6, 2020.

Thus far, the majority of people who have died from the new coronavirus have been elderly patients or those with preexisting health problems. A recent JAMA study of found that the median age of a COVID-19 patient was between 49 and 56 years old. Chinese authorities have reported that most cases in China are among those ages 60 and older.

A study published in January speculated that “children might be less likely to become infected or, if infected, may show milder symptoms” than adults.

Read more about the coronavirus:

Everything we know about the
Wuhan coronavirus
outbreak

One map shows how the coronavirus outbreak has spread to 41 countries around the world

Men represent the majority of coronavirus cases so far. Researchers think smoking could play a role.

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