UKHSA update on scarlet fever and invasive group A strep

The latest data from the UK Health Security Agency (UKHSA) continue to indicate that there is an out-of-season increase in scarlet fever and group A strep infections. Cases usually show the steepest rises in the new year but have increased sharply in recent weeks.

So far this season (from 12 September to 4 December) there have been 6,601 notifications of scarlet fever. This compares to a total of 2,538 at the same point in the year during the last comparably high season in 2017 to 2018.

In very rare occasions, the bacteria causing scarlet fever, group A streptococcus (GAS) can get into the bloodstream and cause an illness called invasive group A strep (iGAS), which can be very serious, particularly in older, younger and more vulnerable groups. iGAS cases across all age groups are slightly higher than expected at this time of year. The latest data continues to highlight a higher proportion of iGAS cases in children than we would normally see. However, iGAS remains uncommon.

So far this season, there have been 85 iGAS cases in children aged 1 to 4 compared to 194 cases in that age group across the whole of the last comparably high season in 2017 to 2018. There have been 60 cases in children aged 5 to 9 compared to 117 across the whole of the last comparably high season in 2017 to 2018. The majority of cases continue to be in those over 45.

Sadly, so far this season there have been 60 deaths across all age groups in England. This figure includes 13 children under 18. In the 2017 to 2018 season, there were 355 deaths in total across the season, including 27 deaths in children under 18.

Cases of GAS usually increase during the winter and the last time significant numbers of cases were reported was in the 2017 to 2018 season. Seasons with high cases can occur every 3 to 4 years but social distancing measures implemented during the coronavirus (COVID-19) pandemic may have interrupted this cycle and explain the current increase being observed.

Currently, there is no evidence that a new strain of GAS is circulating or any increase in antibiotic resistance. Antibiotics are the best treatment and work well against the circulating strains. The increase is likely to reflect increased susceptibility to these infections in children due to low numbers of cases during the pandemic, along with current circulation of respiratory viruses, which may increase the chances of children becoming seriously unwell. However, investigations are under way to understand if there are other factors that could be contributing to the increase this season and to better understand who is currently most affected.

Dr Colin Brown, Deputy Director, UKHSA, said:

Scarlet fever and ‘strep throat’ are common childhood illnesses that can be treated easily with antibiotics. Please visit NHS.UK, contact 111 online or your GP surgery if your child has symptoms of this infection so they can be assessed for treatment.

Very rarely, the bacteria can get into the bloodstream and cause more serious illness called invasive group A strep. 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 are 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.

Good hand and respiratory hygiene are important for stopping the spread of many bugs. By teaching your child how to wash their hands properly with soap for 20 seconds, using a tissue to catch coughs and sneezes, and keeping away from others when feeling unwell, they will be able to reduce the risk of picking up or spreading infections.

There are lots of viruses that cause sore throats, colds and coughs circulating. These should resolve without medical intervention. However, children can on occasion develop a bacterial infection on top of a virus and that can make them more unwell. As a parent, if you feel that your child seems seriously unwell, you should trust your own judgement.

Call 999 or go to A&E if:

• your child is having difficulty breathing – you may notice grunting noises or their tummy sucking under their ribs
• there are pauses when your child breathes
• your child’s skin, tongue or lips are blue
• your child is floppy and will not wake up or stay awake

Note: We analyse scarlet fever seasons from week 37 to week 36 the following year. The majority of cases would typically be seen from the beginning of February to April.

Previous updatesFriday 2 December 2022

The latest data from the UK Health Security Agency (UKHSA) shows that scarlet fever cases continue to remain higher than we would typically see at this time of year.

There were 851 cases reported in week 46, compared to an average of 186 for the preceding years.

Scarlet fever is usually a mild illness, but it is highly infectious. Therefore, look out for symptoms in your child, which include a sore throat, headache, and fever, along with a fine, pinkish or red body rash with a sandpapery feel. On darker skin, the rash can be more difficult to detect visually but will have a sandpapery feel. Contact NHS 111 or your GP if you suspect your child has scarlet fever, because early treatment of scarlet fever with antibiotics is important to reduce the risk of complications such as pneumonia or a bloodstream infection. If your child has scarlet fever, keep them at home until at least 24 hours after the start of antibiotic treatment to avoid spreading the infection to others.

Scarlet fever is caused by bacteria called group A streptococci. These bacteria also cause other respiratory and skin infections such as strep throat and impetigo.

In very rare occasions, the bacteria can get into the bloodstream and cause an illness called invasive group A strep (iGAS). While still uncommon, there has been an increase in invasive group A strep cases this year, particularly in children under 10. There were 2.3 cases per 100,000 children aged 1 to 4 compared to an average of 0.5 in the pre-pandemic seasons (2017 to 2019) and 1.1 cases per 100,000 children aged 5 to 9 compared to the pre-pandemic average of 0.3 (2017 to 2019) at the same time of the year.

So far this season there have been 5 recorded deaths within 7 days of an iGAS diagnosis in children under 10 in England. During the last high season for group A strep infection (2017 to 2018) there were 4 deaths in children under 10 in the equivalent period.

Investigations are also underway following reports of an increase in lower respiratory tract group A strep infections in children over the past few weeks, which have caused severe illness.

Currently, there is no evidence that a new strain is circulating. The increase is most likely related to high amounts of circulating bacteria and social mixing.

There are lots of viruses that cause sore throats, colds and coughs circulating. These should resolve without medical intervention. However, children can on occasion develop a bacterial infection on top of a virus and that can make them more unwell.

As a parent, if you feel that your child seems seriously unwell, you should trust your own judgement. Contact NHS 111 or your GP if:

• your child is getting worse
• your child is feeding or eating much less than normal
• your child has had a dry nappy for 12 hours or more or shows other signs of dehydration
• your baby is under 3 months and has a temperature of 38°C, or is older than 3 months and has a temperature of 39°C or higher
• your baby feels hotter than usual when you touch their back or chest, or feels sweaty
• your child is very tired or irritable

Call 999 or go to A&E if:

• your child is having difficulty breathing – you may notice grunting noises or their tummy sucking under their ribs
• there are pauses when your child breathes
• your child’s skin, tongue or lips are blue
• your child is floppy and will not wake up or stay awake

Good hand and respiratory hygiene are important for stopping the spread of many bugs. By teaching your child how to wash their hands properly with soap for 20 seconds, using a tissue to catch coughs and sneezes, and keeping away from others when feeling unwell, they will be able to reduce the risk of picking up or spreading infections.

Dr Colin Brown, Deputy Director, UKHSA, said:

We are seeing a higher number of cases of group A strep this year than usual. The bacteria usually causes 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.