People are being urged to try and limit the spread of viruses if they think they are or their children are infected.
It comes amid a spike in cases of RSV alongside regular winter influenza infections.
The Health Protection Surveillance Centre (HPSC) said influenza activity increased "significantly" in the week of December 14th, with increasing numbers of influenza cases being reported.
Respiratory Syncytial Virus, or RSV, is a common respiratory virus that usually causes mild, cold-like symptoms.
It particularly affects children under a year old.
Monaghan-based GP Dr Illona Duffy told The Hard Shoulder the number of infections is larger this year because of the low base from the COVID-19 pandemic.
"I think most years it's like this - we probably forgot during COVID because obviously with people isolating and not mixing and mingling we saw a dramatic drop in all of these winter viral infections," she said.
"This year, similar to last year, we're seeing a surge - although it has to be said there probably are more admissions in children this year than last year with RSV in particular".
Virus v bacteria
Dr Duffy said such viruses spread much quicker than a bacterial infection.
"Everything like RSV, COVID, influenza and other adenoviruses will tend to spread because we're coughing, we're sneezing.
"It's aerosol based, often it'll land on the table in front of you, somebody else touches it and they then become contaminated and infected.
"It's winter time, doors and windows are closed.
"We're finding children are in school or in creches; once one gets it it likely will spread amongst others.
"So, it's not unexpected and really all we can do is be prepared, and try and limit the spread if we think one of our children or one of ourselves is infected".
Temperatures
Dr Duffy said everyone should have a thermometer in the home.
"It's important to know if you or your child are running a temperature," she said.
"The only way you're going to know that is by checking with a thermometer.
"Touching somebody and saying they feel hot isn't accurate enough.
"If a child or an adult is uncomfortable with a high temperature, we normally say paracetamol is your first line.
"Nurofen or ibuprofen is a second line, but ideally not the first line because it can be harder on the stomach and harder on the kidneys".
Dr Duffy said going to a GP and getting an antibiotic for a viral infection is not going to do anything.
However those who are not getting better after a few days should seek medical advice.
