New Strep A strain is behind surge of scarlet fever in England and Wales

A new Streptococcus A strain may explain a recent surge in scarlet fever cases in England and Wales, researchers say. England saw 15,000 scarlet fever cases in 2014 — the highest since 1960 — but that number increased to over 19,000 in 2016. Researchers found that a new strain of Strep A, which releases a toxin that causes scarlet fever and other infections, was only responsible for 5% of cases in England in early 2014, but was responsible for a third of all cases by 2016. A similar trend followed in Wales: Some 30% of cases in 2015 were due to the new strain, but more than 40% of scarlet fever cases in 2016 were caused by the new Strep A strain. More research is needed to assess how this new strain responds to antibiotic treatment.