A pupil at a school in Sussex who is suspected to have had invasive Strep A infection has died, the UK Health Security Agency (UKHSA) has said.
The pupil, whose age nor gender were given, had attended Hove Park School.
Specialists from the UKHSA are working with Brighton and Hove City Council to support the school following the death.
Dr Rachael Hornigold, consultant in health protection at UKHSA South East, said: "We are extremely saddened to hear about the death of a young child and our thoughts are with their family, friends and the local community.
"Infection with Group A Streptococcus bacterium usually causes a sore throat, scarlet fever or skin rash, and is passed by physical contact or through droplets from sneezing or coughing.
"In very rare cases, the infection can become invasive and enter parts of the body where bacteria aren't normally found, which can be serious.
"We will implement public health actions, including advice to the city council and school community."
Alistair Hill, director of Public Health at Brighton & Hove City Council, said: "We are working with the UK Health Security Agency and Hove Park School following the death of a pupil who attended the school.
"We offer our heartfelt condolences to the family, friends, and the whole school community who will all be deeply affected by the very tragic loss of this young child, and we are providing our support to them at this incredibly sad time."
Strep A bacteria can cause many different infections, ranging from minor illnesses to serious and deadly diseases. They include scarlet fever, strep throat and the skin infection impetigo.
While the vast majority of Strep A infections are relatively mild, sometimes the bacteria cause serious and life-threatening invasive Group A Streptococcal disease.
Anyone concerned that their child seems seriously unwell is advised to contact NHS 111 or their GP.
UKHSA officials have suggested that a lack of mixing due to the Covid pandemic plus susceptibility in children are probably “bringing forward the normal scarlet fever season” from spring to this side of Christmas.
However, the agency has said 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.
Figures show that scarlet fever cases remain much higher than normal.
The UKHSA said cases usually show steepest rises in the New Year, but have increased sharply in recent weeks.
So far this season (from September 12 to December 4), there have been 6,601 cases of scarlet fever, more than twice as high as the 2,538 at the same point in the last comparably high season in 2017/2018.
Health Secretary Steve Barclay insisted on Wednesday that checks within the Department of Health have not revealed an issue with supply of the medicines.
However, the National Pharmacy Association has pointed to “blips” in the supply chain of liquid penicillin, while the Association of Independent Multiple Pharmacies said pharmacists across the country were struggling to source all they need.