Public Health England has labelled new data showing a steep increase in scarlet fever cases ‘a concern’, as the number of notifications has risen to its highest level for five years.
The new data released last week, saw a sharp increase in reports of scarlet fever at the beginning of 2018, with a continued rise expected.
The report, detailing the seasonal activity of group A streptococcal (GAS) infections, follows a key message issued last month which highlighted an increase in the number of GP consultations dealing with scarlet fever, while the number related to influenza-like illness has decreased.
A total of 6,225 scarlet fever notifications were received between week 37 of 2017 and week four of 2018. This compares with 3,764 over the same period in 2016/17. Between 22 and 28 January this year alone there were 719 notifications.
The highest rates were seen in the North East and North West, at 19 per 100,000 and 14.6 per 100,000 respectively. In contrast, the East of England had the lowest rate at 6.1 per 100,000. All regions had higher notifications than this time last year.
The report stated: ‘Since the peak reported in the 2013/14 season, levels of scarlet fever have remained elevated, possibly reflecting heightened awareness and improved diagnosis and/or notification practices.’
Worryingly, cases of invasive GAS have also risen by 26% at this point in the season when compared with levels in previous years. PHE has said it is unsure if this is related to heightened activity of scarlet fever, or influenza, which is known to predispose the condition.
GAS infections normally leads to mild illness of the throat or skin, where the bacteria resides, but they can become invasive and life threatening if spread to other areas such as the blood or lungs. On rare occasions this can lead to necrotising fasciitis and streptococcal toxic shock syndrome.
PHE called the increase a ‘concern’ and reminded doctors to remain ‘mindful’ and ‘maintain a high index of suspicion in relevant patients as early recognition and prompt initiation of specific and supportive therapy for patients with iGAS infection can be life-saving’.
Deputy director of the national infection service at PHE Dr Nick Phin said: ‘Scarlet fever is not uncommon in the winter and spring, but in recent years there has been a noticeable increase in cases.
‘The reason for the current increase in numbers is not clear, but it is possible that greater awareness and improved reporting practices may have contributed to this increase.’
Despite the ‘highly infectious’ disease being ‘not usually life-treatening’ when treated with penicillin, ‘a very small number, who are usually untreated, can develop rheumatic fever or kidney problems’, said Dr Phin.
He added: ‘We are monitoring the situation closely and remind GPs to be aware of the symptoms of scarlet fever and if you suspect patients have the infection, we recommend swift treatment with penicillin.’
The report also looked at antimicrobial susceptibility, and found that 8% of GAS isolates tested through routine surveillance were resistant to erythromycin, higher than in previous seasons, when resistance varied from 5 to 7%. Despite this, testing against other antimicrobials saw no changes from previous years.
PHE has recommended that GPs prescribe penicillin, as no penicillin-resistant GAS has yet been detected and it acts to reduce the infectiousness of the patient.
RCGP chair Professor Helen Stokes-Lampard said: ‘Scarlet fever used to be a lot more common than it is now, but GPs are noticing more cases than in previous years at the moment. If a patient thinks that they, or their child, might have symptoms, they should seek medical assistance.’
PHE concluded that ‘close monitoring, rapid and decisive response to potential outbreaks and early treatment of scarlet fever is vital, especially given the potential complications associated with GAS infections’.