Doctors are urging parents to check their children for symptoms of strep A after six youngsters have lost their lives to the potentially fatal infection.

On Friday the UK Health Security Agency (UKHSA) issued a rare warning when they told families to seek medical support if they detect signs of the virus in young people.

Symptoms of strep A include a sore throat, fever and minor skin infections but advanced stages of the illness can lead to high fevers, severe muscle aches, unexplained vomiting and diarrhoea. Anyone showing signs of there should contact 999 or go to A&E.

On average one or two children aged 10 or under die from strep A throughout the winter, but five young people from England and one in Wales have already died from the illness this season.

Experts believe the rise in deaths are linked to high amounts of circulating bacteria and social interaction.

Most cases of strep A are mild, but the virus can progress into a life-threatening illness called group A streptococcal disease.

On Friday the UKHSA reported there were 851 cases of strep A in the week of 14 - 20 November, a significant rise from the average of 186 for the same period in previous years.

The agency went on to report there has been 2.3 cases of iGAS per 100,000 children aged one to four in England this year in comparison to an average of 0.5 in pre-pandemic seasons between 2017 and 2019. There has also been 1.1 cases per 100,000 children aged five to nine, compared with 0.3 throughout the pre-pandmeic records.

Dr Colin Brown, deputy director of UKHSA, said in a statement: “We are seeing a higher number of cases of group A strep this year than usual.

“The bacteria usually cause a mild infection producing sore throats or scarlet fever that can be easily treated with antibiotics. In very rare circumstances, this bacteria can get into the bloodstream and cause serious illness called invasive group A strep ( iGAS ).

“This is still uncommon. However, it is important that parents are on the lookout for symptoms and see a doctor as quickly as possible so that their child can be treated and we can stop the infection becoming serious.

“Make sure you talk to a health professional if your child is showing signs of deteriorating after a bout of scarlet fever, a sore throat, or a respiratory infection.”

The UKHSA revealed they were investigating a rise in lower respiratory tract strep A infections in children which have led to a severe illness over the past few weeks.

A child from St John’s primary school in Ealing, west London, recently died from strep A. There have been two further deaths from the illness after parents of a four-year-old boy from Buckinghamshire also lost their lives after contracting the virus.

Hannah Roap, 7, who attended Victoria primary school in Penarth and a six-year-old from Surrey were the third and forth cases who died from strep A in England.

A fifth death was reported on Friday after another child has died since September.

Parents are advised to call 999 or take their child to A&E if they are struggling to breathe, such as grunting noises or tummy sucking in under the ribs, blue colour to their skin, tongue or lips, or if they are floppy and won’t wake up or stay awake.

Dr Simon Clarke, a microbiologist at the University of Reading, said: “I’m unaware of any factor linking these reported deaths, so it’s impossible to link them, but I do expect there to be further cases over the coming weeks and months.

“It strikes me that as we are seeing with flu at the moment, lack of mixing in kids may have caused a drop in population-wide immunity that could increase transmission, particularly in school-age children.”

Strep A bacteria spread through contact with droplets from an infected person when they talk, cough, or sneeze.