U.S. health officials have long worried about flu cases coinciding with COVID-19 cases during the winter and the toll it can take on hospitals.
Now, countries are documenting their first cases of patients with both illnesses in what’s called "flurona"— a combination of COVID-19 and influenza. Here’s what’s known about the dual illness.
What is ‘flurona’?
"Flurona" is the colloquial term used to describe when a patient has been diagnosed with COVID-19 and influenza at the same time. It’s unclear who coined the term. The U.S. Centers for Disease Control and Prevention and the World Health Organization haven’t appeared to have officially endorsed the term.
Where have ‘flurona’ cases been documented?
Israel recently confirmed what is believed to be one of the first documented cases of an individual infected with both the flu and COVID-19. An unvaccinated pregnant woman tested positive for both illnesses last week at the Beilinson Hospital in Petah Tikva, the Times of Israel reported.
"The disease is the same disease. They’re viral and cause difficulty breathing since both attack the upper respiratory tract," Arnon Vizhnitser, the director of the hospital's gynecology department, told the newspaper.
A few cases of ‘flurona’ have been documented in the United States now, too.
A COVID-19 testing site in Los Angeles County recently confirmed the first known local case of the "flurona." Officials at the 911 COVID-19 testing site in Brentwood said a child tested positive for both Influenza A and SARS-CoV-2. In addition, the boy’s mother tested positive for COVID-19 the next day. The two had just returned from a family vacation in Cabo San Lucas. However, officials say the other family members tested negative for COVID-19.
A Houston teenager said he has recovered after contracting COVID-19 and the flu at the same time, according to local reports.
Other cases have been reported in the Philippines, Brazil, and Hungary.
How does the flu differ from COVID-19?
The CDC said both the flu and COVID-19 are respiratory illnesses caused by different viruses. However, COVID-19 can spread easier than the flu and cause more severe symptoms.
Symptoms of both illnesses can include fever or feeling feverish/having chills, cough, shortness of breath, sore throat, and runny or stuffy nose.
But there are differences. The CDC says a person with the flu experiences symptoms anywhere from one to four days after infection. However, a person with COVID-19 experiences symptoms about five days after being infected, but symptoms can appear two to 14 days after infection.
CDC officials said because some of the symptoms of flu and COVID-19 are similar, the difference between them cannot be made based on symptoms alone.
Testing is needed to confirm a diagnosis.
People can be infected with both flu and the virus that causes COVID-19 at the same time and have symptoms of both influenza and COVID-19, according to the agency.
Is ‘flurona’ any worse than the flu or COVID-19?
The CDC and WHO have not said whether having both illnesses at the same time is worse or milder than having the illnesses separately.
However, health officials urge that vaccinations against both the flu and COVID-19 are the best way to protect yourself.
How prevalent is the flu this winter?
The U.S. flu season has arrived on schedule after a mild 2020 season, with flu hospitalizations rising and two child deaths reported in December.
Last winter’s flu season was the lowest on record, likely because COVID-19 measures — school closures, distancing, masks and canceled travel — prevented the spread of influenza, or because the coronavirus somehow pushed aside other viruses. During last winter’s unusually light flu season, one child died. In contrast, 199 children died from flu two years ago, and 144 the year before that.
In the newest data, the most intense flu activity was in the nation’s capital, Washington, D.C., and the number of states with high flu activity rose from three to seven. In CDC figures released, states with high flu activity are New Mexico, Kansas, Indiana, New Jersey, Tennessee, Georgia and North Dakota.
There are early signs that fewer people are getting flu shots compared with last year. With hospitals already stretched by COVID-19, it’s more important than ever to get a flu shot and take other precautions, said Lynnette Brammer, who tracks flu-like illnesses for the CDC.
"Cover your cough. Wash your hands. Stay home if you’re sick," Brammer said. "If you do get flu, there are antivirals you can talk to your doctor about that can prevent severe illness and help you stay out of the hospital."
The Associated Press contributed to this report. This story was reported from Los Angeles.