'Winter trifecta': Pediatricians break down how to know if your child has the flu, COVID or RSV

SAN FRANCISCO (KGO) -- Multiple respiratory viruses are circulating across the country sending children to emergency rooms. On Monday, a child under age 5 died from RSV in California.

ABC7 News reporter Luz Pena spoke to multiple pediatricians who helped break down how you can know if your child has the flu or RSV, and when you should be concerned.

"It's the winter trifecta. We are seeing it all right now," said Dr. Lisa Dana, pediatrician at Golden Gate Pediatrics.

Dr. Naomi Bardach pointed out that it's unusual to see hospitalizations of RSV this early in the season. Children being back at school could be a factor.

MORE: Is the US facing a potential 'tripledemic' of flu, RSV and COVID-19?

"We are not sure why this year it's so much worse and so much earlier," said Dr. Bardach, UCSF pediatrician.

How can you know what virus your child has?

"Sometimes it's really hard to tell the difference," said Dr. Bardach.

Dr. Dana and Dr. Bardach said getting tested is the only way to know for sure.

MORE: 'This is our pandemic': UCSF says its children's hospitals are 'overflowing' as RSV cases soar

Here's a few insights. Let's start with influenza. The symptoms could include stomach pain along with:

"Runny nose, cough, fever, sometimes it will look like a regular cold," said Dr. Bardach.

COVID symptoms are very similar to influenza.

"Mostly runny nose, cough, fever, body aches which you can also get with influenza," said Dr. Bardach.

MORE: RSV in children: Symptoms, treatment and what parents should know

But what makes RSV different is how it impacts the lungs.

"RSV for the little ones - they do tend to have much more snot just to be frank about it," explained Dr. Bardach, "The little kids have such little bronchioles that even a little bit of mucus and swelling can make them sick. That is where RSV causes the problems. It's bronchiolitis, influenza. When you get really sick with influenza it's because pneumonia happens which is actually the entire tissue of the lung even out to the very furthest part, not just the bronchioles," said Dr. Bardach..

According to the CDC, most patients recover from RSV in a week or two. So, when should you be concerned?

"When they are working hard to breathe. When they are having respiratory distress. When there is a fever that is just not responding," said Dr. Dana.

Both pediatricians recommend to get your children vaccinated with COVID, and flu shots. But there's not a RSV vaccine available yet.

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