Bay Area pediatric hospitals are seeing a rise in cases of respiratory syncytial virus, or RSV, a common viral illness that can cause trouble breathing for infants and young children — part of a nationwide surge that has grown particularly severe in some parts of the country, doctors said.

Surveillance shows RSV detections, emergency-room visits and hospitalizations are increasing “in multiple U.S. regions, with some regions nearing seasonal peak levels,”
according to an alert
on the Centers for Disease Control and Prevention website.

In the Bay Area, beds at both the San Francisco and Oakland campuses of UCSF Benioff Children’s Hospitals are “quite full” amid the spike in RSV cases, said Dr. Ted Ruel, chief of pediatric infectious diseases, on Wednesday.

“This is similar to how it is on bad days in normal winters, but very unusual for October,” he said.

However, he said the hospital is not so severely impacted that it is turning patients away. “We are still able to accept critical transfers and admissions,” he said.

Meanwhile, hospitals in other parts of the U.S. including the East Coast, Midwest, Southeast and Southern California are reportedly
seeing resources stretched very thin.

The rise comes as many children’s hospitals are facing stretched resources due to influxes of patients with various issues, including COVID-19, the flu and mental health problems, according to
the Children’s Hospital Association.

What is RSV?

RSV is not new, doctors stressed — it has been around for decades, and can be contracted more than once, with most children first getting the virus before age 3.

Typically, the disease involves mild cold-like symptoms, and most children are able to get over it quickly,
according to the CDC.

“It’s the single most common respiratory pathogen that children encounter,” said Dr. David Cornfield, director of respiratory therapy at Stanford Medicine Children’s Health. “It’s ubiquitous.”

But for some, the disease can be very harmful. According to the CDC, RSV is the most common cause of bronchiolitis and pneumonia in children under age 1 in the U.S., and it typically sends about 2% to 5% of children who get it to the hospital each year.

Why are cases surging this year?

Peak numbers for RSV usually occur starting in November through February. But this year, the rise is happening earlier and volumes are higher.

That’s because prevention measures during the pandemic, including school closures and masking, meant that many children who would have normally come into contact with the virus in daily life did not, Cornfield said.

RSV cases dropped dramatically in 2020, the first year of the pandemic. But they
surged last summer
as COVID restrictions eased. While this year’s uptick got off to a slower start, positive tests this month have recently exceeded the numbers from this time last year,
according to CDC data.

An electron micrograph of the respiratory syncytial virus.

Bsip, Contributor / UIG via Getty Images

With even more people returning to normal behaviors this year, all of those children who never developed any immunity to RSV are now getting exposed to it, leading to the higher volume of patients, Cornfield said.

Fortunately, those children are not getting sicker than they have in the past, said Ruel.

“We’re not concerned that this is some sort of hyper virulent or more aggressive strain of RSV,” he said. “It’s not that kids are necessarily getting sicker, it’s just we’re getting a larger volume.”

Will the Bay Area surge worsen?

According to
CDC surveillance data
based on testing, the incidence of RSV in the Western U.S. is lower than in every other region except for Florida, which is measured on its own rather than with the rest of the South.

Ruel said that he wasn’t sure whether that meant that California was just behind and will keep seeing cases rise, or that the West won’t see as much of an impact — but hospitals are prepared for either possibility.

“We’re braced for numbers to go up,” he said.

Cornfield added that children’s hospitals’ resources are always strained — but not because they don’t have room for patients.

“I think that children’s hospitals around the Bay are full, and capacity is always constrained,” he said — not for lack of beds, but for skilled personnel to staff them. “That is a problem at most hospitals across the country.”

How to minimize risk

Anyone can get RSV, though it is riskiest for infants, older adults and other medically vulnerable people. For children under 5, it causes 58,000 hospitalizations and up to 300 deaths per year,
according to the CDC.

There are steps people can take to minimize the chances of their child ending up in the hospital, the doctors said.

RSV is transmitted through infected droplets that you get in your mouth, nose or eyes through a cough or sneeze from an infected person, touching a surface with the virus on it before washing your hands, or through direct contact, such as kissing the face of a child who has RSV,
according to the CDC.

Many of the measures that prevent the spread of COVID-19 also prevent RSV — washing your hands often, staying home when sick, and keeping people who are sick at home away from others in the family as much as possible.

Symptoms and treatment

RSV symptoms include runny nose, decreased appetite, coughing, sneezing, fever and wheezing,
according to the CDC.

In very young infants, the only symptoms may be irritability, decreased activity, decreased appetite or pauses while breathing, known as apnea, the CDC says.

If a child is displaying symptoms of RSV, parents can take several steps to help them get through it, doctors said. That includes making sure the child is well hydrated, keeping their fever down with acetaminophen or ibuprofen, and, for babies, suctioning out mucus from the nose with a bulb syringe to make sure their breathing is not impaired.

While a runny nose alone isn’t cause to go to the hospital, Ruel said, parents should keep an eye out for symptoms that would indicate something more severe is going on — children struggling to breathe, causing the skin to suck in around the ribs or neck, or preventing them from eating or drinking well.

If those occur, parents should seek medical care immediately, experts say.

Children hospitalized for RSV may require oxygen, intubation or mechanical ventilation to help them breathe. With such supportive care, most improve and are discharged in a few days, the CDC says.

Doctors stressed that it’s important to keep your child safe from other illnesses as well. While there’s no vaccine for RSV, parents can prevent their child from ending up in the hospital with COVID-19 or the flu, as well as from coinfection from any combination of the three, by getting their child the flu shot and COVID vaccine.

“With things we can prevent, getting people those vaccines up to date will help keep those kids less sick and also keep less of a burden on our hospitals,” Ruel said.

Danielle Echeverria is a San Francisco Chronicle staff writer. Email: Twitter: @DanielleEchev