Record breaking levels of scarlet fever have been reported in west London with Ealing seeing the biggest rise.
There were 113 suspected cases of the disease, a contagious bacterial infection, reported to Public Health England (PHE) in the four weeks to March 27, as the peak season for the illness gets underway.
The figures were a third higher (31.4%) than the 86 cases reported in the same period in 2015 in west London.
The recent rise has seen advice issued to parents who fear their children may have been infected .
Ealing saw the biggest increase with 25 cases reported this year compared to seven over the four weeks last year.
The second largest jump was seen in Hounslow where cases more than doubled from seven to 18.
In comparison, Kensington and Chelsea reported seven cases of scarlet fever in March 2016, three more than the previous year; Westminster went one up from four to five; Hillingdon from 15 cases to 17 and Brent from 14 to 15 reported cases.
Scarlet fever is most common in young children and in the past cases have been reported at schools.
The only two boroughs in west London to see fewer number of cases were Hammersmith and Fulham from 20 in March 2015 down to 14 in March 2016 or 30% drop, and Harrow from 15 to 12 or a 20% drop.
| Local Authority | March (to 29/3/15) | March (to 27/3/16) | Compared to last year |
| Ealing | 7 | 25 | 257.1 |
| Hounslow | 7 | 18 | 157.1 |
| Kensington & Chelsea | 4 | 7 | 75 |
| Westminster | 4 | 5 | 25 |
| Hillingdon | 15 | 17 | 13.3 |
| Brent | 14 | 15 | 7.1 |
| Harrow | 15 | 12 | -20 |
| Hammersmith & Fulham | 20 | 14 | -30 |
'Extraordinary rise'
Dr Theresa Lamagni, PHE’s head of streptococcal infection surveillance, said: “While we hope the Easter school break assisted in slowing down transmission of the bacteria causing scarlet fever, we cannot assume or rely on this being the case.
"As such, our investigations and assessment of the impact of this extraordinary rise in scarlet fever continue.
“As we reach peak season for scarlet fever, health practitioners should be particular mindful of the current high levels of scarlet fever when assessing patients.
“Close monitoring, rapid and decisive response to potential outbreaks and early treatment of scarlet fever with an appropriate antibiotic remains essential, especially given the potential complications associated with group A streptococcal infections.”
Across England, the highest week on record in recent decades saw 1,319 cases reported between March 21 and 27, 2016, according to data from PHE.
A total of 10,570 cases of scarlet fever have now been reported since the season began in September 2015, and is the third season in a row to record elevated scarlet fever activity.
Scarlet fever is most common between the ages of two and eight and symptoms include a sore throat, headache, fever and rash.
PHE advises at the first sign of these people should to consult their GP and start on a course of antibiotics to treat the infection.
Advice is to stay home until at least 24 hours after the starting the medication to avoid passing it on.
