Thirty people have died, including 12 children, in an “unusual upsurge” of invasive strep A disease over the past year, according to a new report.
The number of invasive Group A Streptococcus (iGAS) cases has been running at 4.5 times the normal level since October 2022, with a higher than average proportion in children, the report by the Health Protection Surveillance Centre states.
This is the first time iGAS infections have surged outside the normal peak during the spring months. This may be partly due to the Covid-19 pandemic, which interrupted normal social mixing patterns, according to the HPSC.
“Reduced exposure to iGAS during the pandemic is likely to have contributed to increased susceptibility to infection in the general population, with particularly severe effects in the most vulnerable subjects,” it says.
There were 354 iGAS cases in the first six months of the year, compared with an average of 78 for the same period in the pre-pandemic years of 2017-19. A similar rise has been recorded in other European countries.
Infections started to ease off in late May but are still at a slightly higher level than would be expected for this time of year, the report says.
Children accounted for almost 40 per cent of the 480 cases recorded since October 2022, up from the previous average of 25 per cent. Ten of the children who died were aged under 10, and two were aged between 10 and 17 years.
A new case definition for the disease since last December has contributed to the rise in notifications, by leading to the reporting of an additional 19 per cent of cases.
The southwest was the worst affected HSE region, with an incidence almost twice the national average.
Flu and other respiratory diseases, and chickenpox, are known risk factors for iGAS. The first peak in iGAS infections last winter mirrored rises in Covid-19 and other respiratory ailments. Last iGAS peaks in children appear to relate to increases in chickenpox.
According to the report, 74 iGAS cases in children had chickenpox either as a co-infection or as a risk factor.
Group A streptococcus is a common bacteria, which many people carry harmlessly in their throats and on their skin. However, it can serious infection. The most serious form occurs when it becomes invasive, such as when it enters the lungs or bloodstream. In rare cases iGAS infections can be fatal.
A common presentation of strep A in children can be scarlet fever which causes symptoms such 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 rash appears 12 to 48 hours later, first on chest and stomach and then spreading.