Scarlet fever cases hit 602 across England and Wales, during the seven days to January 21, Public Health England (PHE) has revealed.
Since the beginning of the year, 1,347 cases of Scarlet fever have been reported; 568 more than the same period last year.
The south east of England reported the most cases over the week, with 102.
Wales only had 28 cases of the disease – the lowest number across the two countries.
In November 2017, Public Health England (PHE) said the recent upsurge in cases was greater than any documented in the last century.
“Guidance on management of outbreaks in schools and nurseries has just been updated and research continues to further investigate the rise,” said PHE’s Head of Streptococcal Surveillance, Dr Theresa Lamangi.
“We encourage parents to be aware of the symptoms of Scarlet fever and to contact their GP if they think their child might have it.”
Once you’ve had Scarlet fever, you’re unlikely to become infected again.
Scarlet fever is most common in young children, but it can affect people of any age.
Signs of the condition tend to develop about a week after becoming infected.
Early signs of scarlet fever include a sore throat, a headache, a fever, vomiting, and swollen glands in the neck, according to the NHS.
But, the most common symptom is the Scarlet fever rash.
The rash usually begins on the chest, and spreads to other parts of the body.
It makes the skin feel a bit like sandpaper, and may be brightest in body folds – elbows or under the arms.
Scarlet fever can also cause a white coating to form on the tongue. The coating peels away after a few days.
The condition isn’t usually serious, and can be treated with antibiotics.