Your kids are adorable germ vectors. Here's how often they get your household sick

I wanted to report this story last month, but I was too sick with COVID. My kid gave it to me.

My colleagues on the health reporting team would have tackled the story, but they've been sick, too, thanks to their children. (Just last week, one colleague dropped off her daughter for her first day back at preschool after recovering from a bug, only to pick her up that same afternoon, sniffling from a new illness. Yikes.)

And we're far from alone in our woes.

"Like so many parents out there, you know, my husband and I have been sick all winter. We've been sneezing, coughing, had fevers. It's gross," says Dr. Rachel Pearson, a pediatrician at The University of Texas Health Science Center at San Antonio and University Hospital. She's also the mother of 2-year-old Sam.

"I feel like half the time he has a virus, has a runny nose, is coughing – to the point where my dad was like, 'Is there something wrong with Sam?' " she says.

With flu, RSV, colds and COVID all coming at once, it can feel like things may be worse than ever for parents of little kids. But as Pearson tells her dad – and the parents of her own young patients – this seemingly never-ending cycle of sniffles is normal, if miserable.

"When I counsel parents, I say you can have a viral infection every month. Some kids are going to cough for four weeks to six weeks after a virus. And so they're going to catch their next virus before they even stop coughing from the last one."

In fact, if you've ever described your child as an adorable little germ vector, you're not wrong, says Dr. Carrie Byington, a pediatric infectious disease specialist and executive vice president for the University of California Health System. And she's got hard data to back that up.

"We all think it, but it was really incredible to have the definitive proof of it," says Byington.

The "proof" she's referring to comes from a study she and her colleagues began back in 2009, when she was at the University of Utah. They wanted to understand the role kids play in the transmission of respiratory viruses in their homes. So they recruited 26 households to take nasal samples of everyone living in the home, every week, for an entire year. What they found was eye-opening.

"We saw as soon as a child entered the house, the proportion of weeks that an adult had an infection increased significantly," Byington says.

And more kids meant more infections. For families with two, three or four kids, someone at home had an infection a little more than half the year. Families with six kids had a viral detection a whopping 87% of the year. Childless households, on the other hand, only had a viral detection 7% of the year.

(Appropriately enough, the study was called Utah BIG-LoVE – an acronym for Better Identification of Germs-Longitudinal Viral Epidemiology.)

The findings also suggest that the youngest kids are the ones bringing germs home most often: Children under age 5 were infected with some kind of respiratory virus a full 50% of the year – twice as often as older kids and adults. And while a viral detection didn't always translate into illness, when they were infected, the littlest kids were 1.5 times more likely to have symptoms, like fever or wheezing.

And that's just respiratory viruses. As Byington notes, the study wasn't even looking at other kinds of infections, such as strep throat, which is caused by bacteria. "So obviously, there could be other things that happened throughout the year to even make it seem worse," she says.

Byington says all of this means that, in the grand scheme of things, it's normal for kids to be getting all these viruses. But it's all more intense right now because of the disruptions of the pandemic. Children were kept at home instead of going to daycare or school, where they would typically be exposed to viruses and bacteria one after another, she says.

As children returned to regular routines, "there were lots of kids ages 1, 2 and 3 who had never really seen a lot of viruses or bacteria," Byinton says. "And so what might have been spread out in the past over 12 months, a year, they were now seeing it all at once in this very concentrated time."

Byington says the pandemic also disrupted the seasonality of viruses. Flu season hit earlier than usual this year, as RSV and COVID were also circulating. Young children without prior exposure to these viruses were hit especially hard.

Pearson notes that's because kids are likely to have a more severe course of illness the first time they encounter a virus like RSV, before they have some level of immunity. She says there's a larger cohort of kids this year that didn't have that prior exposure.

And there is evidence that younger kids who get multiple infections – say, COVID and RSV– at the same time can end up with more severe illness than if they'd gotten just one virus at a time.

The end result is that many pediatric hospitals and care units have seen a surge in sick kids over the fall and winter. That includes University Hospital in San Antonio, where Pearson sees hospitalized kids in the acute care unit.

Nationwide, "pediatric care right now is at this point of strain," Pearson says, not just because of the current surge but because of an underinvestment that predates the pandemic.

And "the kids who get admitted to the hospital are the tip of the iceberg," Pearson says. For every kid sick enough to be hospitalized, there are likely many more with the same virus recuperating at home, she says.

The good news is that the viral stew seems to be easing up. Recent data from the CDC show the number of emergency department visits for flu, COVID and RSV dropped to the lowest they've been since September for all age groups.

But of course, the respiratory virus season isn't over yet.

As for families who are currently living in what one headline memorably dubbed "virus hell," Byington hopes the findings of the BIG-LoVE study should offer some comfort that eventually this, too, shall pass.

"It's nice to have done the study and to offer some real-world data to families that what they're living through is normal and will pass and their children will be well," she says.