New bacteria behind scarlet fever 50-year high

A new strain of bacteria that is fuelling an unprecedented rise in cases of scarlet fever, and can also cause sepsis, has been discovered by scientists.

The disease, which used to kill thousands in Victorian times, reached a 50-year high in 2016.

Now researchers at Imperial College London have found that a new strain of streptococcus (Strep A) – called M1 UK – is behind the trends and may explain the rise in invasive infections, when the bacterium enters the blood or tissue and can trigger sepsis and toxic shock. The research is published in The Lancet Infectious Diseases.