Strep A deaths in children under the age of 15 have now reached 15 in the UK, figures have revealed.
New data from the UK Health Security Agency (UKHSA) showed 13 children under 15 have died in England since September.
Meanwhile, two other deaths of children have been recorded in Northern Ireland and Wales, taking the UK total to 15.
Group A strep bacteria can cause many different infections, ranging from minor illnesses to deadly diseases.
Health Editor Emily Morgan on the Strep A symptoms parents should look out for
Illnesses caused by Strep A include the skin infection impetigo, scarlet fever and strep throat.
While the vast majority of infections are relatively mild, sometimes the bacteria cause a life-threatening illness called invasive Group A Streptococcal disease.
According to the UKHSA, there is no current evidence that a new strain is circulating and the rise in cases is most likely due to high amounts of circulating bacteria and increased social mixing.
The news comes as pharmacists continue to use Twitter to complain of shortages in access to antibiotics, including the liquid version of penicillin, which is often given to children.
Since September, the UKHSA said there have been 652 reports of invasive Strep disease, higher than at the same points over the last five years.
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So far this season, there have been 85 cases in children aged one to four, compared to 194 cases in that age group across the whole of the last high season in 2017/2018.
There have also been 60 cases in children aged five to nine. Since September, 60 deaths have been reported across all age groups in England.
Dr Colin Brown, deputy director of the UKHSA, said: "We know that this is concerning for parents, but I want to stress that while we are seeing an increase in cases in children, this remains very uncommon.
"There a lots of winter bugs circulating that can make your child feel unwell, that mostly aren’t cause for alarm.
"However, make sure you talk to a health professional if your child is getting worse after a bout of scarlet fever, a sore throat or respiratory infection – look out for signs such as a fever that won’t go down, dehydration, extreme tiredness and difficulty breathing."
What are the main symptoms of Strep A?
The main symptoms of Strep A include but are not limited to:
A swollen tongue
Severe muscle aches
Localised muscle tenderness
Redness at the site of a wound.
Anyone who is concerned their child has Strep A is urged to contact 111 online or your nearest GP surgery so they can be assessed for treatment.