A sniffle, a sneeze or a cough can set off alarm bells these days for families with young children.
Mother-of-two Vickie Leon said her kids, ages four and two, can sometimes go a month or two without bringing anything back from daycare. Then there are times when it seems the family in Aurora, Colorado, is sniffling with a virus every other week.
"Once that hits, we are just in it for a while," she said.
Many kids have spent years socially distancing to protect against COVID-19, and now healthcare systems are being overloaded with cases of the respiratory virus RSV - which can cause a runny nose, decreased appetite, coughing, sneezing, fever and wheezing.
The viral infection has always been common. Almost all children catch RSV at some point before they turn 2, the US Centers for Disease Control and Prevention says. And immunity developed after an infection often wanes over time, leading people to have multiple infections in a lifetime, said Dr William Schaffner, a professor in the Division of Infectious Diseases at Vanderbilt University School of Medicine in Nashville, Tennessee.
The public health challenge this year is that while many children were kept home to protect against COVID-19, they were also isolated from RSV, meaning more are having their first - and therefore most severe - infection now, said CNN Medical Analyst Dr Leana Wen, an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health.
An RSV infection is often mild but could be a cause for concern for young infants, children with underlying conditions and older adults, said Schaffner, who is also medical director of the National Foundation for Infectious Diseases.
That doesn't mean it is time to panic, added Wen, who is also author of Lifelines: A Doctor's Journey in the Fight for Public Health. Catching RSV and other viral and bacterial infections is a part of children growing up and developing their immune system.
Here's how to assess when to keep your child home from school and when to visit the paediatrician, according to experts.
Is it cold, flu, COVID or RSV?
Between colds, influenza, strep throat, RSV and lingering COVID-19, there are a lot of infections swirling about this winter - and they can often look a lot alike in terms of symptoms, Schaffner said. Even astute doctors may have trouble telling them apart when a patient is in the office, he added.
However, paediatricians are well practised and equipped to treat upper respiratory infections, even if it isn't possible to distinguish exactly which virus or bacteria is the cause, Wen said.
Whatever virus or bacteria is stirring up sniffles, headache or a sore throat in your household, the age, symptoms and health status of your child will likely make a difference in how you proceed, she said.
Should you keep your kid home?
Ideally, public health professionals would like it if no child showing symptoms were sent to school or daycare, where they could potentially spread infections Schaffner said. But - especially for single parents or caregivers who need to be at work - that is not always the most practical advice, he added.
At-home tests may signal if a child has a COVID-19 infection, he added. But for other viruses like a cold, there may not be a good way to know for sure.
Some symptoms that might really signal it is time to keep your child home from school or daycare include high fever, vomiting, diarrhoea, trouble eating, poor sleep or problems breathing, Wen said.
Donna Mazyck, a registered nurse and executive director of the National Association of School Nurses, breaks it down into two primary considerations: Does the child have a fever and are they too ill to engage with learning fully?
Families should also check their school's guidelines, some of which can be detailed on when a child needs to be kept home from school, while others will rely more on parental judgement, she said.
"When in doubt, consult the school policies and have a plan with a paediatrician," Wen said.
And for children at higher risk because of other medical conditions, consult with your paediatrician before your child gets sick so you know what to look for.
When is it time to send them back?
Again, here is where schools may have different policies and it becomes important to check with written information, a school administrator or school nurse, Wen said.
"Generally, the schools will ask that the child be fever free without the use of fever-reducing medications" before returning to the classroom, she said.
For children with asthma or allergies, it may not be reasonable to keep them out of school whenever they show any coughing or sniffling symptoms, Wen said. That could very well keep them out half the year.
And some symptoms, like a continued cough, may linger as an infection clears and a child recovers. In those cases, it may be appropriate to send a child back to school, Mazyck said, reiterating that it is important to check on the school's guidelines.
When to seek medical help
Families are often good at bringing their children into the paediatrician when they seem unwell, Schaffner said. Still, with so many things going around, it is important to remind families that doctors would rather see kids who aren't feeling well earlier than later, he added.
If they seem lethargic, stop eating or have difficulty breathing, parents and caregivers would also be justified in taking their kids to the paediatrician and seeking medical attention - especially if the symptoms worsen, Schaffner said.
"This is not something that they should hesitate about," he said.
For younger babies and infants, it might be time to go to the emergency room if they are struggling to take in liquid or have dry diapers, flared nostrils, trouble breathing and a chest that contracts when it should expand, Wen added.
Families should seek emergency treatment for school-age kids who have trouble breathing and speaking in complete sentences, Wen said. Fortunately, most will not need emergency treatment - and those who do are usually back home and doing well in a couple days, Schaffner said.
"Parents should know that treating RSV and other respiratory infections is the bread and butter of paediatricians and emergency physicians," Wen said. "This is what we do."
How to prevent sickness and spread
To prevent these respiratory illnesses, teach your children to utilise the hygiene practises health care professionals were promoting long before the pandemic, like washing hands, using hand sanitizer when a sink isn't available, coughing and sneezing into an elbow or tissue, and not sharing food or utensils with friends, Wen said.
There is not yet a vaccine for RSV approved by the US Food and Drug Administration, but there are effective ones available for influenza and COVID-19, Schaffner said.
If your child is not yet vaccinated, talk to their doctor about protecting them against these viruses, he added.
CNN