(CNN) Pediatricians across the United States are sounding the alarm about unusually high numbers of young children being admitted to emergency departments due to respiratory syncytial virus infection or RSV, a common virus that causes cold-like symptoms.
Most people recover in a week or two from the infection, but for infants, RSV can be serious.
In Ohio, the Cleveland Clinic has reported seeing an unusual uptick in pediatric emergency department visits due to RSV this cold and flu season.
"We have had an almost 20% increase in our emergency department visits in just the last few weeks," said Dr. Purva Grover, the medical director of Cleveland Clinic Children's pediatric emergency departments.
"There have been incredibly high volumes of patients coming through this year specifically with RSV and a combination of influenza B as well," she said.
Norton Children's Hospital in Louisville, Kentucky, has also seen a significant rise in RSV cases this season.
"It's been a rough season for RSV as our year-over-year numbers have doubled," Erik Martin, chief nursing officer for the hospital, said in an email on Friday.
"In the last four months, Norton Children's Hospital has diagnosed more than 800 cases. During the same time period a year ago, we had fewer than 300," he said. "We also had positive RSV tests throughout the summer. That's rather uncommon as during a typical summer we can go weeks without a confirmed case."
In New York, clinics and emergency departments also have seen more children for RSV this season compared to prior seasons and the season came earlier, Dr. Edith Bracho-Sanchez, a primary care pediatrician and assistant professor of pediatrics at Columbia University in New York, said in an email on Friday.
In the South, data from the Florida Department of Health shows that the percent of emergency department and urgent care center visits for RSV among children younger than 5 across the state has been much higher this season than in the previous three seasons.
"The peak of RSV is usually in November, December, January," said Dr. Patricia Emmanuel, chair of pediatrics at USF Health in Tampa.
"It actually is a longer season in Florida -- and sometimes we'll see it earlier in the fall and it will sometimes go well into spring -- but we did see a real uptick in late 2019," she said.
As for why there have been some unusually high numbers of cases and hospitalizations this current season, "we don't know," Bracho-Sanchez said in her email. "It is a little hard to know exactly how much worse this season is. RSV is not a reportable infection in the way that influenza is, for example."
Since RSV is not a condition that is required to be reported to the US Centers for Disease Control and Prevention, the agency does not have data on cases, hospitalizations or deaths due to RSV, according to an emailed statement from CDC spokesman Scott Pauley on Friday.
"The season for RSV in the U.S. runs fall, winter, and spring. We can't say if it has peaked for several reasons—first, this season isn't over yet (since we just started winter); second, NREVSS doesn't track actual cases, it collects laboratory results; finally reporting delays happen for some labs so the data on those charts may change," Pauley said.
It can be difficult to predict when a cold and flu season might see unusual RSV activity compared with years' past and why, but this current season has caused some concern among physicians, Grover said.
She is part of an email listserv for emergency pediatricians across the country, and she said that recently she has seen several emails concerning RSV.
Martin said he has heard of other hospital systems seeing higher volumes in RSV cases, too.
"It's been a tough fall and winter for upper respiratory illnesses in general," he said. "It's also concerning because RSV typically peaks in late December through early February. The fact that we've already seen so many cases means we could be in for a rough ride for a few more months."
RSV remains among one of the common infections most people will get, and almost all children will be infected with RSV by their second birthday, according to the CDC. Symptoms of RSV infection usually include runny nose, decrease in appetite, coughing, sneezing, fever and wheezing.
"For most adults and children, RSV simply presents like a cold, but for infants -- especially those born prematurely -- and young children with other health issues, the virus can be deadly," Martin said.
Emmanuel had similar sentiments.
"For most people, it's cold symptoms and sore throat and runny nose but it is most severe and most concerning in young babies and in infants less than a year of age," she said, adding that if RSV infects a child's lower respiratory tract, it can cause a pneumonia or bronchiolitis, which are serious lung infections.
In severe RSV cases, "we're mostly worried about oxygen and hydration," Emmanuel said.
"Two of the main reasons why babies get admitted to the hospital is either because their oxygen is low -- they can't keep up the oxygen level -- or they're getting dehydrated."
If your young child has been diagnosed with RSV, you can try to determine whether they are dehydrated by monitoring their diapers, Grover said.
If your infant has fewer than about six wet diapers a day or if your toddler has no wet diapers for eight hours, that could be a sign of dehydration, according to Cleveland Clinic. The American Academy of Pediatrics recommends calling your pediatrician right away if your child has fewer than one wet diaper every eight hours.
"I would urge the parents to keep an eye out for that," Grover said, adding that parents should look out for difficulty breathing and signs of respiratory distress.
In addition to dehydration, parents should look for other symptoms, including difficulty breathing, fever in a baby who is younger than 2 months or a high fever that doesn't come down with fever medication among older children and a fever that lasts three days or longer, Bracho-Sanchez said.
Overall, "for most it'll pass like most colds and viruses do and only a small percentage of children will ever require a hospital admission," she said. "The most important thing for parents is not to panic."
There are ways to prevent RSV, such as simply washing your hands often and avoiding close contact with people who may be sick, Martin said.
"Unfortunately there is no vaccine but there are steps families and parents can take to prevent the virus from spreading," Martin said.
"If your child is displaying symptoms of RSV, it's a good idea to visit the pediatrician's office for testing. However, if the child is really struggling to breathe, a trip to the emergency room might be in order," he said. "RSV is very manageable for most, but it needs to be taken seriously, and parents and caregivers should monitor their child closely."