Update on Group A streptococcus


There has been an increase in notified invasive Group A Streptococcus (iGAS) infections in Ireland since October 2022.

In a normal year, iGAS infections typically peak during the first six months. The increase observed towards the end of 2022 is the first time a peak has been reported outside this usual peak period. During the pandemic, normal social mixing patterns were interrupted which led to changes in how diseases such as iGAS presented.

Between 2nd October 2022 and 10th June 2023, 384 cases of iGAS were notified in Ireland. Of these, 155 (or 40%) were in children aged <18 years, of whom 136 were aged 0-9 years. This contrasts with the pre-pandemic years when approximately 25% of iGAS infections were in children aged <18 years.

Data from 2023 indicate that the number of iGAS cases continues to remain at higher levels than expected, with 305 cases notified in the first five months compared with an average of 67 cases during the pre-pandemic years 2017-2019.

Since October 2022, there have been 12 deaths in children (10 in children aged under 10 years old and two in children aged 10-17 years) and 13 in adults (age range, 46-96 years).

Group A streptococcus
Group A streptococcus is a common bacteria. Lots of us carry it in our throats and on our skin and it doesn’t always result in illness. However, Group A streptococcus does cause a number of infections, some mild and some more serious.

The most serious infection caused by Group A streptococcus occurs when it becomes invasive (invasive group A strep). That is when the bacteria gets into parts of the body where it is not normally found, such as the lungs or bloodstream. This is called invasive Group A Strep (iGAS) and in rare cases it can be fatal.

Whilst iGAS infections are still uncommon, there has been an increase in cases this year reported in Ireland since October 2022, particularly in children under 10 and sadly, a small number of deaths.

How is it spread?
Group A streptococcus is spread by close contact with an infected person and can be passed on through coughs and sneezes or from a wound.

Some people can have the bacteria present in their body without feeling unwell or showing any symptoms of infections and while they can pass it on, the risk of spread is much greater when a person is unwell.

Which infections does Group A streptococcus cause?
Group A streptococcus causes infections in the skin, soft tissue and respiratory tract. It’s responsible for infections such as tonsillitis, pharyngitis, scarlet fever, impetigo and cellulitis among others.

While infections like these can be unpleasant, they rarely become serious. When treated with antibiotics, an unwell person with a mild illness like tonsillitis stops being contagious around 24 hours after starting their medication.

A common presentation of Group A streptococcus in children can be scarlet fever which causes the following symptoms: fever, a raised rash which can feel rough to the touch like sandpaper, sore throat, and a swollen tongue.

The first signs of scarlet fever can be flu-like symptoms, including a high temperature, a sore throat and swollen neck glands (a large lump on the side of your neck).

A rash appears 12 to 48 hours later. It looks like small, raised bumps and starts on the chest and tummy, then spreads. The rash makes your skin feel rough, like sandpaper. The rash will be less visible on darker skin but will still feel like sandpaper. More information on scarlet fever can be found on the HSE and HPSC websites.

What is invasive group A strep?
The most serious infections linked to Group A streptococcus come from invasive group A strep, known as iGAS.

This can happen when a person has sores or open wounds that allow the bacteria to get into the tissue, or inside the body, or people who have damage to their respiratory tract after a viral illness, or in a person who has a health condition that reduces their immunity to infection. When the immune system is compromised, a person is more vulnerable to severe, invasive disease.

What infections does invasive group A strep cause?
Necrotising fasciitis, necrotising pneumonia and Streptococcal Toxic Shock Syndrome are some of the most severe but rare forms of iGAS.

What is being done to investigate the rise in cases in children?
A number of countries are seeing increases in iGAS, especially in children. This upsurge in cases is continuing, but there are signs that the numbers of cases are beginning to fall.

The Irish Meningococcal and Sepsis Reference Laboratory (based in Children’s University Hospital, Temple Street) are currently carrying out investigations to determine if a particular strain of Group A streptococcus (or Strep A) is responsible for the increase in iGAS infections in children and in the wider population in Ireland.

There have been reports of similar increases in iGAS infections amongst paediatric patients in other countries, including the Netherlands and France. The reason for such increases is not fully understood as yet. There is likely a combination of factors, including increased social mixing compared to the previous years as well the effects of higher levels of respiratory viruses such as COVID-19, flu and RSV, and more recently chickenpox which can predispose, especially children to iGAS infection.

What should parents look out for?
It’s always concerning when a child is unwell. Group A streptococcus infections cause various symptoms such as sore throat, fever, chills and muscle aches.

As a parent, if you feel that your child is seriously unwell, you should trust your own judgement.

Contact 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 an Emergency Department 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 has a rash that does not fade when you press a glass against it
  • your child’s skin, tongue or lips are blue
  • If your child’s skin is pale, and feels cold and clammy
  • If your child has a seizure (convulsion or fit)
  • your child is floppy and will not wake up or stay awake

How can we stop infections from spreading?
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 and warm water for 20 seconds, using a tissue to catch coughs and sneezes, and keeping away from others (and out of childcare or school) when they are feeling unwell, they will be able to reduce the risk of picking up, or spreading, infections.

Keeping your child up to date with their vaccines will also help them to keep well. Data from the UK over a 4 year period suggests that the nasal flu vaccine may reduce Strep A infections in children.