Research and analysis

Group A streptococcal infections: report on seasonal activity in England, 2025 to 2026

Published 30 October 2025

Applies to England

Main points

Scarlet fever activity for the current 2025 to 2026 group A streptococcal (GAS) season remains in line with normal seasonal patterns, with GP consultations within expected levels for the time of year. Laboratory notifications of invasive group A streptococcal (iGAS) infection are currrently at the higher end of what is expected for the time of year.

Given the potential for severe presentations, scarlet fever cases should be treated promptly with antibiotics to limit further spread and reduce risk of potential complications in cases and their close contacts. Clinicians should continue to be alert to the severe complications of GAS infections and maintain a high degree of clinical suspicion when assessing patients, particularly those with preceding viral infection (including chickenpox) or their close contacts.

Updated UK public health guidance on the management of close contacts of iGAS cases in community settings was published on 15 December 2022, with public health action extended to include patients with probable invasive GAS infection and additional close contact groups recommended for antibiotic prophylaxis. The evidence base underpinning the change in risk groups has been published.

National guidance on the management of scarlet fever outbreaks highlights essential tools to limit spread: prompt notification of scarlet fever cases and outbreaks to UK Health Security Agency (UKHSA) Health Protection Teams (HPTs); collection of throat swabs (prior to commencing antibiotics) when there is uncertainty about the diagnosis; and exclusion of cases from school and work until 24 hours of antibiotic treatment has been received.

Numbers presented in this seasonal activity update are based on data available as of 22 October 2025 for diagnoses up to and including 19 October 2025 (end of week 42). Numbers presented may change as updated data becomes available.

Key definitions are available at the end of the report.

Scarlet fever

So far this season (week 37, 2025 to week 42, 2025), normal seasonal increases are being observed for GP in-hours consultations for scarlet fever and they remain within expected levels (Figure 1). For the latest week, the rate (0.52, week 42, 2025) falls within the range (0.02 to 1.54) observed for the same week in the last 6 seasons (2019/20 season to 2024/25 season). The highest weekly rate of in-hours GP consultations has so far been observed in the latest 2 weeks (41 and 42) at 0.52 per 100,000 registered population.

Figure 1. Weekly Scarlet fever notifications in England, 2017 to 2018 onwards (weeks 37 to 42)

Note: Data shown for the current season goes up to week 42 (19 October 2025).

Invasive group A streptococcal infection

Laboratory notifications of iGAS infection so far this season (week 37, 2025 up to week 19, 2025) are at the higher end of the range expected (Figure 2). A total of 235 notifications of iGAS disease have been received, with week 40 seeing the highest peak so far this season with 51 notifications (week commencing 29 September 2025). Cumulative numbers of iGAS infections so far this season are both higher than average (177) and outside of the range (81 to 229) for the same period in the prior five seasons (2019/20 to 2024/25 seasons, excluding the 2022/23 upsurge season). The first few weeks of this GAS season displays a similar trend to that seen during the early part of the 2022/23 season, though total numbers for the current season are lower than for the same point early in the 2022/23 season, 235 compared to 269.

So far this season, the highest notification rates were in the North East (0.6 per 100,000 population), followed by the East of England, the South West, and Yorkshire and the Humber (all 0.5 per 100,000). Lowest rates were seen in the South West, London, and East Midlands (all 0.3 per 100,000).

Figure 2. Weekly laboratory notifications of invasive GAS, England, 2019 to 2020 season onwards

Note: Numbers of notifications in the latest weeks of the 2025 to 2026 season are expected to increase due to a lag in laboratory reporting. The decline in notifications in recent weeks should be interpreted with caution; delayed processing and reporting timeframes are represented by a dashed line between weeks 41 and 42 of 2025.

Rates of iGAS infection to date this season are highest in those aged 75 years and over (1.3 per 100,000). The second highest rate so far is in those aged 64 to 74years (0.8 per 100,000), followed by individuals under 1 year old (0.7 per 100,000). The lowest notification rate was observed in 5 to 9 year-olds, 0.1 per 100,000.

The median age of notified cases of iGAS infection so far this season is 57 years (range of 0 to 101 years). This is within the range of the median age ranges reported for this point in the preceding five seasons (50 to 62 years).

Antimicrobial susceptibility results from routine laboratory surveillance for iGAS infection so far this season (week 37 2025 to 42 2025) continue show elevated levels of tetracycline and erythromycin resistance, higher than the range seen in the previous 6 seasons, with co-resistance to both tetracycline and erythromycin identified in 16% of sterile site isolates. Changes in the resistance rates are likely to reflect dominant emm types currently circulating.

Specifically:

• 10% were resistant to clindamycin (8% in 2024/25; range 5% to 13% in the last 6 seasons)
• 30% were resistant to erythromycin (18% in 2024/25; range 6% to 12% in last 6 seasons)
• 48% were resistant to tetracycline (41% in 2024/25; range 16% to 41% in the last 6 seasons)

Analysis of reference laboratory iGAS isolate submissions indicated a diverse range of emm gene sequence types identified to date this season (week 37 2025 to week 42 2025), with emm 49.8 remaining the most common type (16.9% of all referrals), followed by emm 76.0 (6.1%) and emm 89.0 (5.0%). This compares to emm 49.8 (12.3%), emm 89.0 (8.3%) and emm 33.0 (6.8%) which were the top 3 emm types at the same point last season.

Discussion

Following the 2022/23 season, which saw a period of considerable elevation in scarlet fever notifications (1, 2) and unusual seasonal patterns, the 2023/24 season saw a return to more usual GAS activity. At this point in the 2025/26 season, scarlet fever rates are in line with expected levels.

Invasive GAS infection cases are displaying a similar trend to that shown in the 2022/23 upsurge period. Although it is still too early in the season to discern general trends, the total numbers so far this season are lower than what they were for the same period during the upsurge.

This season, emm 49.8 has emerged as the most common emm type, the same as the previous season. GAS remains universally susceptible to penicillin which remains the drug of choice. Detailed genomic and biological investigations are under way to investigate this emergence.

Prompt treatment of scarlet fever with antibiotics is recommended to reduce risk of possible complications and limit onward transmission. GPs and other frontline clinical staff are also reminded of the increased risk of invasive disease among household contacts of scarlet fever cases (3). Clinicians should continue to maintain a high index of suspicion in relevant patients for invasive disease as early recognition facilitates prompt initiation of specific and supportive therapy for patients with iGAS infection.

Relevant guidelines and FAQs are available on GOV.UK:

• guidelines for the public health management of scarlet fever outbreaks in schools, nurseries and other childcare settings
• scarlet fever: symptoms, diagnosis and treatment
• guidelines for the management of close community contacts of invasive GAS cases
• prevention and control of group A streptococcal infection in acute healthcare and maternity settings
• Report a Notifiable Disease (eNOIDS)

All invasive disease isolates – and also non-invasive isolates – from suspected clusters or outbreaks should be submitted for typing to:

Staphylococcus and Streptococcus Reference Section
Antimicrobial Resistance and Healthcare Associated Infections (AMRHAI)
UK Health Security Agency
61 Colindale Avenue
London
NW9 5HT

Data sources and methods

Scarlet fever data is presented as GP in-hours consultation rates per 100,000 registered population. This information is collected from UKHSA’s GP in-hours syndromic surveillance system; this system is sentinel, which means that not all GP practices in England are included, and coverage varies by UKHSA region, so comparison between geographic regions is not recommended. The system currently includes approximately 19 million registered patients across England. The data included is from 2 sources: technology provider TPP and ORCHID (Oxford and Royal College of General Practitioners Clinical Informatics Digital Hub). The indicator for scarlet fever syndromic is based on diagnoses recorded during GP in-hours patient consultations, and diagnoses are based on signs/symptoms and may not be laboratory confirmed. The weekly rates presented differ from the daily rates reported as standard elsewhere.

Invasive GAS laboratory notification data was extracted from the UKHSA Second Generation Surveillance System (SGSS) and combined with specimen referrals to the Staphylococcus and Streptococcus Reference Section to produce a total number of episodes for England. Data was extracted on 22 October 2025.

Antimicrobial resistance data is based on phenotypic test results for tetracycline, erythromycin, or clindamycin reported by laboratories to SGSS and are reported as susceptible or resistant. Co-resistance data is based on data where both tetracycline and erythromycin results have been reported for the iGAS episode.

Population rates are calculated per 100,000 using the relevant year’s ONS mid-year population estimate.

The M protein gene (emm) encodes the cell surface M virulence protein. Information for the emm gene was extracted from UKHSA’s reference laboratory and this report contains data covering the period 8 September 2025 to 19 October 2025.

Prior to the COVID-19 pandemic, there were a number of seasons when elevated incidence of scarlet fever and iGAS was seen, in particular the 2017/18 season. During the pandemic there was an unprecedented reduction in the number of scarlet fever and iGAS notifications, affecting the 2019/20 season and the 2021/22 season.

References

1. Guy R, Henderson KL, Coelho J, Hughes H, Mason EL, Gerver SM and others (2023). ‘Increase in invasive group A streptococcal infection notifications, England, 2022’. Eurosurveillance: volume 28, number 1.

2. Bundle N, and others (2017). ‘Ongoing outbreak of invasive and non-invasive disease due to group A Streptococcus (GAS) type emm66 among homeless and people who inject drugs in England and Wales, January to December 2016’. Eurosurveillance: volume 22, number 3.

3. Lamagni T, and others (2018). ‘Resurgence of scarlet fever in England, 2014 to 2016: a population-based surveillance study’. The Lancet Infectious Diseases: volume 18, number 2, pages 180 to 187.

Acknowledgements

These reports would not be possible without the weekly contributions from microbiology colleagues in laboratories across England, without whom there would be no surveillance data. Feedback and specific queries about this report are welcome via hcai.amrdepartment@ukhsa.gov.uk.