Public Health England (PHE) says 20,372 cases of scarlet fever have been reported since mid-September 2017, compared to an average of 9,461 for the same period over the last five years.
In the week to 8 April, 1,180 cases of scarlet fever were reported, although this figure is likely to increase as further reports come in. Almost 2,000 cases were reported in the 12th week of 2018 - more than a third higher than the peak last year - and likely to be the highest level since records began.
Rates of scarlet fever across England are varied, but all areas are reporting higher levels than at the same time last year.
Scarlet fever rise
The north west of England is facing the highest rate of scarlet fever, with 54 cases per 100,000 population. In the north east of England 50.5 cases per 100,000 population have been reported, dropping to 48 in the east Midlands and 45.2 in the south east of England. In the east of England, just 19.7 cases per 100,000 have been seen.
The vast majority of cases (89%) have been among children aged under 10 years old - with rates of scarlet fever as high as 1,488 per 100,000 population at times during the current season.
Deputy director of the PHE national infection service said: 'We are urging parents to look out for the symptoms of scarlet fever such as a sore throat, fever and rash after seeing a significant upsurge in cases this year. The good news is that over the Easter holidays we have seen a slight decline in cases, which may indicate that activity has peaked.
'Scarlet fever, which mainly affects young children, is not usually a serious illness and can be easily treated with the appropriate antibiotics. We encourage parents to contact their GP or NHS 111 if they spot symptoms of scarlet fever or have concerns.'
