Cases of possible Flurona 'twindemic' — a combination of COVID-19 and flu — might be flying under the radar but isn't 'overly concerning,' expert says

• Anecdotal reports of "flurona" — the flu plus COVID-19 — are appearing around the US.
• People from five states said they tested positive for COVID-19 and flu at the same time.

Cases of "flurona" — a combination of the flu and COVID-19 — have been reported by people in five states in recent days.

But cases of the co-infection might be more widespread than the numbers suggest, as doctors don't routinely test for the flu.

The idea that flu could co-infect with COVID-19 is not new. As the two waves of disease sweep across the country, they are bound to come across the same person at the same time, a phenomenon referred to as a "twindemic."

Co-infections of many diseases with the flu are "exceedingly common," The LA County Department of Public Health told the LA Times, although there have been only a few cases of flu and COVID-19 definitively found altogether.

That could be because the symptoms for the two diseases are extremely similar and that doctors in the US don't routinely test patients for flu unless they are in a hospital setting, per the CDC.

This could mean that milder flurona cases were happening all the time without anyone noticing.

"We are not tracking these occurrences systematically and cannot tell you how frequently they have occurred," LA health officials told the LA Times in a statement.

Another potential reason is that there were comparatively few cases of flu in 2021 altogether.

Is the spread of flurona concerning?

Carrying both the coronavirus and the flu virus at the same time is not in itself "overly concerning," Steve Farzam, the chief operating officer of a testing center in Los Angeles, told the LA Times.

But the increased prevalence of both COVID-19 and the flu means the two conditions appear to be increasingly interacting.

Here are the cases that have been reported, by state:

• California: one unvaccinated teen returning to LA from Mexico. He had only mild symptoms and is recovering at home, per the LA Times.
• Texas: Alec Zierlein, a 17-year-old teen, was found to have flurona over Christmas after getting mild cold-like symptoms, per ABC News 13. He was double vaccinated for COVID-19, but not for flu.
  
  Galveston's University of Texas Medical Branch also recorded three cases of "flurona," one of which was a child, per ABC News 13. All patients are recovering well, said Dr. Janak Patel, an official from the hospital, per ABC.
  
  Another child was found to have the co-infection in a children's hospital in Houston, per KXAN. The patient was not hospitalized and is recovering at home, per KXAN.
• Kansas: one unnamed patient in a medical center outside of Kansas City was found to have flurona before being admitted to the ICU. Whether they had been vaccinated was not mentioned. It is not clear whether their serious condition is due to the infections.
  
  Kansas health provider Stormont Vail also reported cases, although not provide any information about the cases, per local news outlet 13 NEWS.
  
  Double vaccinated Wichita resident Gary Ayers also reported having tested double-positive, per KWCH12, and having only mild symptoms.
• Mississippi: Bobby Rose, a Batesville man, was vaccinated but not boosted when he and his daughter caught both infections. They reported flu-like illness, per Fox 13 News.
• North Carolina: Fox News reported that a seven-year boy was on bed rest for two days around Christmas after the co-infection was detected. He had received his second dose of COVID-19 vaccine a month earlier, per Fox.

This is not the first time cases have been reported in the US. A hospital in New York reported the co-infection as early as February 2020, per The Atlantic. Other countries like Israel and the Philippines have also reported anecdotal cases, per The Washington Post.

Experts have said that in healthy, vaccinated individuals, flurona is no cause for concern.

"It is concerning and can be problematic for someone who has preexisting medical conditions, anyone who is immunocompromised," Farzam, the LA testing expert, told the LA Times.

The best bet is to get vaccinated against both diseases, experts have said.