Children infected with Covid-19 who also carry other viruses are more likely to end up in intensive care, a major study involving Ireland and other European countries has revealed.
The finding that such children are at greater risk will have implications for the winter months.
Twenty-nine children were found to be infected with one or more additional respiratory viruses such as a cold or flu at the same time as having coronavirus.
The first Europe-wide study of children confirms Covid-19 predominantly causes mild disease in children and fatalities are very rare, but some had to be treated in ICU.
The findings, published in The Lancet Child and Adolescent Health, from 25 European countries showed only a quarter of the 582 children had pre- existing medical conditions.
"A notable number of children do develop severe disease and require intensive care support, and this should be accounted for when planning and prioritising healthcare resources as the pandemic progresses," said lead author Dr Marc Tebruegge, of the UCL Great Ormond Street Institute of Child Health in London.
Four patients died during the study period, two of whom had pre-existing medical conditions.
All of those who died were older than 10 years of age.
The news came as another death from the virus was announced here by the Department of Health.
There have now been 1,727 Covid-19 deaths in Ireland.
Eleven new cases of the virus were confirmed, bringing that total to 25,405.
Chief Medical Officer Dr Tony Holohan said the National Public Health Emergency Team (Nphet), which met yesterday, highlighted how more than a third of new cases in the past 14 days were under 35 years of age.
It also noted a number of EU countries reported an increase in new cases.
Dr Holohan warned that 7pc of cases notified in Ireland over the past fortnight had been associated with travel.
"Nphet expressed a clear view that overseas travel poses a risk to importation of the disease and to further transmission in Ireland," he said.
"The European Centre for Disease Control has recently warned that the pandemic is not over. Ireland has made significant gains in suppressing Covid-19.
"Our task over the coming weeks and months is maintaining these gains."
Deputy Chief Medical Officer Dr Ronan Glynn said: "Covid-19 is accelerating globally with four million cases recorded.
"Considering the international experience with the disease, we cannot afford complacency. Continue to be aware of the risks and follow the public health advice designed to protect individuals."
St Vincent's Hospital infectious disease consultant Dr Paddy Mallon said there was still no coherent plan for managing the Covid-19 pandemic in Ireland.
He said it was essential there was a fast-acting testing and tracing system here to pick up the infection quickly, but the turnaround time was still not good enough.
It takes more than two days from point of referral for a test to tracing contacts and it should be one day, he told the Oireachtas Special Committee on Covid-19 Response.
The flu vaccine should be mandatory for health workers, he added.
Asked about the spread of the virus in nursing homes, he said that from his experience there was a big variation in how individual homes coped with the risk. The key was examining the management of nursing homes, he added.
There was still major concern about the ability of hospitals and the health service to cope with another surge, and we had managed to overcome the first phase "by the skin of our teeth", Dr Mallon said.
Hospitals had been seen to be short of specialists and capacity, and asking them to ramp up again would be like asking the population to go into lockdown again, he added.