GPs are seeing 'a massive rise' in viral infections, especially among younger children.
Respiratory Syncytial Virus (RSV) is a common respiratory virus that usually causes mild, cold-like symptoms.
Most people recover in a week or two, but RSV can be serious - especially for infants and older adults.
RSV causes coughs and colds every winter and is the most common cause of bronchiolitis in infants.
It is an important cause of severe respiratory illness among children under two - and is also the most common cause of hospital admissions due to acute respiratory illness in young children.
Monaghan-based GP Dr Illona Duffy told The Pat Kenny Show the picture has changed this year.
"We're definitely seeing a massive rise and a big spike in the general viruses we would see.
"So September time is always a busy time in General Practice, but obviously last September because of COVID we didn't see this.
"These are the infections we see when kids return to school, or typically parents who start their child in a creche or in school, will notice that they seem to get one infection after another.
"RSV is one of the typical ones... Really the reality of it is they all have similar type symptoms.
"The viral symptoms are unfortunately the same symptoms that we see with COVID.
"It can vary from the runny nose to the cough to the gastric symptoms - vomiting and diarrhoea - they may or may not have temperatures.
"At the moment definitely we're seeing a lot of kids with temperatures and sore throats.
"We know they're not bacterial, but we also have to worry 'Could they be COVID?'"
Dr Duffy says that the "very infectious" nature of RSV means it spreads fast.
"Definitely on the ground in General Practice we're seeing that where classrooms of kids at schools are all going out sick.
"My own family I'm seeing it, where all my kids have been sick with it.
"Definitely we're seeing this as being much more contagious, even than COVID.
"I think that's to be expected: if you've one child in your house who's sick and suddenly everybody's sick, you know this is more likely to be viral because bacteria don't spread as quickly".
Viruses 'being brought home'
She says says babies born during the pandemic may be particularly susceptible.
"I think it's very hard for parents because all along we're kind of telling them 'Be worried if they have symptoms, contact your GP'.
"And I think as well that many of the very younger children have never met these viruses before, and instead of being able to handle them and maybe have mild symptoms, we're definitely seeing them with more symptoms.
"So the cough is a bit worse, they're maybe that bit more short of breath, they're wheezy - and they're not handling it as well because they haven't built up that innate immunity that we all do by meeting these viruses every year.
"The very young children... who were born during COVID, they've never met anything.
"A lot of younger children, if they have siblings, are meeting the viruses being brought home by their older siblings.
"So they are meeting them at home, even if they're being looked after and cared fully for at home".
Dr Duffy recommends that parents should first get advice from the HSE online.
"I think the big thing is getting that balance of knowing when do you need to see your GP, when should you be talking to them and when should we as doctors actually physically examine them, and not just give you advice over the phone.
"The HSE have a wonderful website called undertheweather.ie and I think it offers really good advice on management of all these common viruses - and not only the viruses, but the common presentations - such as what to do if your child has a cough, what to do if your child has vomiting and diarrhoea".
She says the best way to treat children is to treat their temperatures and make sure they are staying hydrated.