NEW YORK CITY -- In September, an 8-month-old baby came into Dr. Juanita Mora's office in Chicago with an infection the doctor hadn't expected to see for another two months: RSV.
Like her peers across the country, the allergist and immunologist has been treating little ones with this cold-like virus well before the season usually starts.
"We're seeing RSV infections going rampant all throughout the country," Mora said.
Almost all children catch RSV at some point before they turn 2, the US Centers for Disease Control and Prevention says. Most adults who catch it have a mild illness; for those who are elderly or who have chronic heart or lung disease or a weakened immune system, it can be dangerous. But RSV can be especially tricky for infants and kids.
Mora, a volunteer medical spokesperson for the American Lung Association, says it's important for parents, caregivers and daycare workers to know what to watch for with RSV, which stands for respiratory syncytial virus. That way, they know whether a sick child can be treated at home or needs to go to a hospital.
"The emergency department is getting completely flooded with all these sick kids, so we want parents to know they can go to their pediatrician and get tested for RSV, influenza and even Covid-19," Mora said.
Here's what else parents need to know amid the surge of respiratory illnesses.
What to watch for
For many, RSV causes a mild illness that can be managed at home.
On average, an infection lasts five days to a couple of weeks, and it will often go away on its own, the CDC says. Sometimes, the cough can linger for up to four weeks, pediatricians say.
Symptoms may look like a common cold: a runny nose, a decreased appetite, coughing, sneezing, fever and wheezing. Young infants may seem only irritable or lethargic and have trouble breathing.
Not every child will have every potential RSV symptom.
"Fevers are really hit or miss with RSV infections, especially in young infants," said Dr. Priya Soni, assistant professor of pediatric infectious diseases at Cedars Sinai Medical Center.
Parents should watch for any changes in behavior, she said, including taking longer to eat or not being interested in food at all. The child can also develop a severe cough and some wheezing.
It's also important to watch for signs that your child is struggling to breathe or breathing with their ribs or belly -- "symptoms which may kind of overlap with many of the other viruses that we're seeing a resurgence of," Soni added.
Since it's not easy for parents to tell the difference between respiratory illnesses like, say, RSV and flu, it's good to take a sick child to a pediatrician, who can run tests to pinpoint the cause.
"You may need to take your baby to be evaluated sooner rather than later," Soni said.
When it comes to RSV, parents should be especially cautious if their children are preemies, newborns, children with weakened immune systems or neuromuscular disorders, and those under age 2 with chronic lung and heart conditions, the CDC says.
"Parents should be really astute to any changes, like in their activity and their appetite, and then pay particular attention to any signs of respiratory distress," Soni said.
Testing is important because treatment for things like flu and Covid-19 may differ.
There's no antiviral or specific treatment for RSV like there is for the flu, nor is there a vaccine. But if your child is sick, there are things you can do to help.
Fever and pain can be managed with non-aspirin pain relievers like acetaminophen or ibuprofen. Also make sure your child drinks enough fluids.
"RSV can make kids very dehydrated, especially when they're not eating or drinking, especially when we're talking infants," Mora said. "Once they stop eating or their urine output has decreased, they're not having as many wet diapers, this is a sign they may have to go to the pediatrician or emergency department."
Talk to your pediatrician before giving your child any over-the-counter cold medicines, which can sometimes contain ingredients that aren't good for kids.
When to go to the hospital
Your pediatrician will check the child's respiratory rate -- how fast they're breathing -- and their oxygen levels. If your child is very sick or at high risk of severe illness, the doctor may want them to go to a hospital.
"RSV can be super dangerous for some young infants and younger kids, particularly those that are less than 2 years of age," Soni said.
Mora said labored breathing is a sign that a child is having trouble with this virus. RSV can turn into more serious illnesses such as bronchiolitis or pneumonia, and that can lead to respiratory failure.
If you see that a child's chest is moving up and down when they breathe, if their cough won't let them sleep or if it's getting worse, "that might be a sign that they need to seek help from their pediatrician or take them to the emergency department, because then they might need a supplemental oxygen, or they may need a nebulization treatment."
CNN medical analyst Dr. Leana Wen says this respiratory difficulty -- including a bobbing head, a flaring nose or grunting -- is one of two major trouble signs with any respiratory infection. The other is dehydration. "That particularly applies to babies with stuffy noses. They may not be feeding."
Much of the care provided by hospital staff will be to help with breathing.
"We provide supportive measures for RSV and these kids with oxygen, IV fluids and respiratory therapies, including suctioning," Soni said.
A thin tube may need to be inserted into their lungs to remove mucus. A child can get extra oxygen through a mask or through a tube that attaches to their nose. Some children may need to use an oxygen tent. Those who are struggling a lot may need a ventilator.
Some babies might also need to be fed by tube.
How to prevent RSV
The best ways to prevent RSV infections, doctors say, is to teach kids to cough and sneeze into a tissue or into their elbows rather than their hands. Also try to keep frequently touched surfaces clean.
If a caregiver or older sibling is sick, Mora says, they should wear a mask around other people and wash their hands frequently.
And most of all, if anyone is sick -- child or adult -- they should stay home so they don't spread the illness.
There is a monoclonal antibody treatment for children who are at highest risk for severe disease. It's not available for everyone, but it can protect those who are most vulnerable. It comes in the form of a shot that a child can get every month during the typical RSV season. Talk to your doctor about whether your child qualifies.