Cases of a respiratory illness commonly seen in winter are increasing.

"Particularly in the South part of the U.S., we have seen an increase in what's called RSV, or respiratory syncytial virus. It's a virus that causes a cold much like influenza causes a cold, though it can be severe in very young children and elderly adults," says Dr. Gregory Poland, an infectious diseases physician and researcher at Mayo Clinic.

RSV, influenza and COVID-19 are all respiratory infections that share similar symptoms, except for the loss of taste or smell that can occur with COVID-19 ― unless there are complications.

Symptoms of severe RSV include:

  • Fever.
  • Severe cough.
  • Wheezing.
  • Rapid breathing or difficulty breathing, especially when lying down.
  • Bluish color of the skin, or cyanosis, due to lack of oxygen.
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Poland says you cannot distinguish between illnesses just by clinical symptoms, unless you had the loss of taste and smell, which would mean you may have COVID-19. He says getting tested to find out what sickness you may have is critical. That way you can get on the right treatment and avoid spreading the illness to other people.

"It is important to seek medical care to get that swab because if it's influenza, we can treat it. If it's RSV or COVID-19, and it advances or gets worse, there are things we can do," Poland says.

Poland urges people able to get the COVID-19 vaccination to do so.

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