The viruses of winter arrived early this year, and hospitals and doctor’s offices are filling up with sniffling and coughing children.
Viruses that are typically most prevalent in colder months — including respiratory syncytial virus, or RSV, enterovirus, and rhinovirus — started attacking kids this summer. Then, as schools reopened in the fall, the virus that gets the most attention these days — COVID-19 — spiked among children and teens.
The pediatric intensive care unit at the Mass General for Children is full, and Boston Children’s Hospital reports high patient volume and longer wait times.
Primary care offices are also feeling the effects.
“Pediatricians are definitely seeing a high volume of respiratory illnesses this fall. We are seeing more viral infections but also seeing slightly different infections for this time of year,” Dr. Mary Beth Miotto, president of the Massachusetts Chapter of the American Academy of Pediatrics, said in an e-mail.
RSV is a common virus that usually causes a mild cold for a week or two. But it can be dangerous for infants, especially those who are born prematurely or have other illnesses. Nationwide, an estimated 58,000 children younger than 5 are hospitalized with RSV each year.
RSV is normally prevalent December through March, but it’s circulating now, said Miotto, who works at the Mattapan Community Health Center in Boston.
Doctors are also seeing rhinovirus, the predominant cause of the common cold, and enteroviruses, which infect the intestine but also cause respiratory symptoms.
Of particular concern is enterovirus-D68, which in rare cases has been linked to a polio-like paralytic illness in children. The Centers for Disease Control and Prevention reported this week that EV-D68, as well as other enteroviruses and rhinoviruses, had increased during this past summer, along with more emergency department visits by children with respiratory illnesses.
Meanwhile, COVID-19 is spiking in Massachusetts, particularly among school-age children. The number of confirmed cases for children ages 10 to 19 over a two-week period jumped nearly 60 percent from 1,191 to 1,901. There was also an 8.7 percent increase among children ages 0 to 4, and a 27.8 percent increase among children 5 to 9.
But so far there is little sign of influenza — although that virus is expected to storm through in a few weeks.
Doctors speculate that the infection-control efforts surrounding COVID-19 kept children safe from other viruses as well. That surely saved lives, but it also prevented children from developing immunity to these common bugs.
“Because there was almost a two-year period of time that children were having a decreased exposure to common respiratory viruses, their immunity may be decreased,” said Dr. Kristin Moffitt, an infectious diseases specialist at Boston Children’s Hospital. Before the pandemic, a child might have been exposed to rhinovirus four or five times before age 6, she said; today’s 6-year-old may have encountered the virus only once or twice.
Now that many COVID precautions have been dropped, and children are gathering at schools and day care centers, germs are finding fertile ground.
”We don’t have any of the required mitigation practices in place that we saw in place throughout most of the school year last year,” Moffitt said. “There’s more mingling. More exposure, especially indoors.” Even children too young for school have older siblings who bring viruses and bacteria home.
And infants and toddlers are most likely to get severely ill, because their airways are tiny and their immune systems immature, she said.
Dr. Bernard Kinane, chief of the pediatric pulmonary unit at Mass General for Children, said that doctors didn’t see any of the usual respiratory viruses during the height of the pandemic.
Then, as people resumed gathering without masks, “We saw a resurgence of viral illnesses,” he said. “Viruses that we normally saw in the wintertime, we now started seeing in the summertime.
“We’re used to getting viral illness in cycles. COVID just jumped into the cycle and shifted it,” Kinane said. “We saw wintertime-full ICUs in the summer. It’s a normal January — in August.”
That pattern has continued into September. The 14-bed children’s ICU at Mass. General is still full, Kinane said. But the hospital can take care of all who need it, just as it does in the winter, he said.
Kinane expressed no alarm. These illnesses, he said, are “inevitable and manageable.” Most children recover fully.
Still, there are precautions parents can take. Doctors have clear, if familiar, advice.
They recommend flu shots for adults and children age 6 months and older, and strongly urge people to get all COVID-19 shots and boosters for which they are eligible.
Additionally, it’s wise to stay home when sick and to keep sniffling or feverish children out of school. Boston Children’s is urging parents to contact the child’s primary care doctor first instead of immediately rushing to the hospital, where waits may be long.
Meanwhile, those with respiratory symptoms (cough, sneeze, runny nose), should wear a mask, even if they don’t have COVID-19.
And everyone should wash hands often, especially when they have symptoms.
Martin Finucane of the Globe staff contributed to this report.
Felice J. Freyer can be reached at email@example.com. Follow her on Twitter @felicejfreyer.