Coronavirus vs. flu: Here's how you can tell the difference
USA TODAY answers a question you may be wondering: Is coronavirus worse than the flu? USA TODAY
The arrival of Arizona's first COVID-19 cases in the middle of flu season have some people wondering how to determine which is which.
Are the symptoms different? Should you be more concerned about the new coronavirus? Why aren't events being cancelled over influenza?
Here's what experts say.
How do COVID-19 symptoms compare to symptoms of influenza?
People with COVID-19 have shown symptoms almost identical to those with the flu, officials say.
Symptoms include fever, coughing, shortness of breath, aches, tiredness, congestion, runny nose, sore throat and sometimes vomiting or diarrhea, according to Johns Hopkins, the World Health Organization and the U.S. Centers for Disease Control and Prevention.
Some cases of flu and COVID-19 result in pneumonia, said Lisa Maragakis, senior director of infection prevention at Johns Hopkins.
One difference: flu symptoms often appear suddenly, within about two to four days after infection, while the effects of the new coronavirus come on more gradually, within two to 14 days after exposure, the CDC said.
In about 80% of cases, the symptoms of COVID-19 will be mild and patients will recover without special treatment, the WHO said. Some people may even get coronavirus without ever feeling unwell.
But about 16% of cases are expected to become serious, the WHO said.
The CDC is recommending that anyone who thinks they've been exposed to COVID-19 and develops a fever and respiratory symptoms such as coughing or difficulty breathing call their doctor immediately.
Can you catch COVID-19 the same way as flu?
Both COVID-19 and the flu are spread through droplets from an infected person who coughs, sneezes or talks, Maragakis said. People can catch them by inhaling the invisible droplets in the air or touching the droplets after they land on surfaces around the person.
One possible difference: COVID-19 droplets may remain in the air, infecting others, even when the sick person is gone, though health officials aren't sure yet.
We also don't know if people are contagious with the new coronavirus before they start having symptoms, as with influenza. If so, it could make the response to the new virus harder.
How contagious is the flu vs. COVID-19?
Early estimates indicate that the new coronavirus is more contagious than influenza, meaning it spreads faster, according to the WHO. But it's not as contagious as diseases like the measles.
Experts say as much as 25%-70% of people worldwide could contract the new coronavirus.
Is the new coronavirus deadlier than the flu?
Yes, COVID-19 is at least 10 times more lethal than influenza, according to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
The flu kills less than 0.1% of people each year, while the fatality rate for the new coronavirus appears to be around 2-3%, according to the WHO.
Worldwide, about 291,000 to 646,000 people die of the flu each year, according to Johns Hopkins, compared to about 4,500 deaths so far in the past few months from COVID-19.
But although influenza has killed more peopleso far this season, COVID-19 could turn out to be deadlier in the long run, especially if preventative measures like canceling events aren't taken, health officials say.
And coronavirus mortality rates are far higher for vulnerable groups like seniors and people with immune deficiencies.
Some studies have shown fatality rates of about 4% for people ages 60 to 70, about 10% for people ages 70 to 80 and about 14-15% for people over age 80, according to former Food and Drug Administration Commissioner Scott Gottlieb.
On the other hand, children appear to be less susceptible to COVID-19 than the flu, according to the CDC.
What are the treatments for flu? Will they work on COVID-19?
Doctors typically recommend fluids, rest and over-the-counter pain medication like Tylenol to beat the flu, while some severe cases require antiviral medications like Tamiflu, according to the Mayo Clinic.
COVID-19 is so new that scientists haven't come up with a drug to treat it.
For mild cases, health officials recommend people stay home and follow similar treatment guidelines to the flu: Liquids, rest and common medicines such as decongestants and pain-relievers such as acetaminophen or ibuprofen to ease fevers and aches, according to Harvard Medical School.
For severe cases, doctors may put patients on oxygen and admit them to the hospital, according to a study published by the National Center for Biotechnology Information.
Is there a vaccine for coronavirus? What about for the flu?
Every year, doctors recommend people get a flu shot, or vaccine, aimed at preventing infection from the strains of influenza most likely to be common that season.
Although people can still catch the flu after getting a vaccine, it usually helps to lessen the symptoms and length of the illness.
There is no vaccine yet for COVID-19, but researchers are working on it, including three at Arizona State University.
Why have events been canceled for COVID-19 and not the flu?
Experts don't know enough about the new coronavirus to predict how it will spread, but they believe it is more lethal than the flu and want to protect as many people as possible.
Data shows preventing transmission early on can slow the spread dramatically, so the number of severe cases at any given time don't overwhelm hospitals and fewer people die.
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