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Main points for annual epidemiological commentary: Gram-negative, MRSA and MSSA bacteraemia and C. difficile infections

Published 24 September 2026

Applies to England

This annual epidemiological commentary on Gram-negative, meticillin-resistant Staphylococcus aureus (MRSA) and meticillin-sensitive Staphylococcus aureus (MSSA) bacteraemia and C. difficile infection (CDI) provides a comprehensive overview of recent trends in infections which forms part of the national mandatory surveillance of healthcare-associated infections (HCAIs). The commentary describes changes in trends of counts of cases and incidence rates, stratified by key demographic and clinical characteristics. Please complete our user survey so we can continue to improve this report.

This page presents only the main, top-level findings in the annual epidemiological report. Further detail for Gram-negative – Escherichia coli (E. coli), Klebsiella species (spp.) and Pseudomonas aeruginosa (P. aeruginosa) – MRSA and MSSA bacteraemia is available at Epidemiological analysis of Gram-negative, MRSA, and MSSA bacteraemia, while additional information for CDI is found at Epidemiological analysis of C. difficile infection.

The Glossary, data sources, and further information for the annual epidemiological commentary up to and including financial year 2025 to 2026 and the quality and methodology information are also available separately. The accompanying data is available in ODS format on the landing page.

Main points

Main points are:

• E. coli continues to be the most prevalent of the Gram-negative bacteraemias, with recent increases primarily caused by community-onset cases

• Klebsiella spp. and P. aeruginosa showed similar increases, with P. aeruginosa showing a steep increase after several stable years, also caused by community-onset cases

• MRSA bacteraemia has increased sharply in recent years, reversing the previously stable trend, while MSSA bacteraemia shows a sustained upward trend with prevalence rates significantly higher than MRSA bacteraemia

• following recent increases in CDI after the COVID-19 pandemic, this year marks the first sustained decline in rates, observed across hospital-onset and community-onset cases

E. coli bacteraemia

In financial year (FY) 2025 to 2026:

• there were 44,879 cases of E. coli bacteraemia, which was an incidence rate of 76.6 cases per 100,000 population

• the incidence rate increased by 2.6% compared with the previous financial year, and this rise was primarily due to increasing community-onset (CO) cases, which represented 81.5% of cases

• this continues the increasing trend in E. coli bacteraemia rates observed over the previous 5 years

Klebsiella species (spp.) bacteraemia

In FY 2025 to 2026:

• there were 13,961 cases of Klebsiella spp. bacteraemia, with an incidence rate of 23.8 cases per 100,000 population

• the incidence rate increased by 3.7% compared with the previous financial year, continuing the trend of year-on-year increases from when surveillance first began in FY 2017 to 2018

• the rise was primarily due to increasing rates of community-onset (CO) cases, representing 71.0% of cases and rising by 6.9% compared with the previous financial year

P. aeruginosa bacteraemia  

In FY 2025 to 2026:

• the incidence rate of P. aeruginosa bacteraemia was 8.1 cases per 100,000 population, which constituted 4,728 cases, and marked a slight increase in the incidence rate of 5.5% compared with the previous year

• while the rate of hospital-onset (HO) cases remained stable, community-onset cases rose by 9.7% compared with the previous financial year and constituted 63.8% of cases

MRSA bacteraemia  

In FY 2025 to 2026:

• MRSA bacteraemia rates continued to increase to 2.0 cases per 100,000 population, with a total of 1,144 cases, after a sustained period of stability ended in FY 2018 to 2019

• HO and CO cases in both the hospital and community settings have contributed to the increasing rate, with CO constituting the majority (65.2%) of cases

MSSA bacteraemia  

In FY 2025 to 2026:

• MSSA bacteraemia rates have risen every year, apart from during the COVID-19 pandemic, and have now reached a rate of 23.8 cases per 100,000 population, with a total of 13,948 cases

• recent increases were mostly due to increases in the rate of CO cases, while HO MSSA bacteraemia rates have remained stable over the past 5 years

C. difficile infections

In FY 2025 to 2026:

• there were 17,114 cases of CDI with a rate of 29.8 cases per 100,000 population

• this marked a 10.0% decrease in the annual CDI rate compared with the previous financial year, after 4 years of sustained increases in CDI (a 45.7% increase from FY 2020 to 2021 to FY 2024 to 2025)

• decreases were observed in both CO and HO CDI rates

More detail is available for Gram-negative, MRSA and MSSA bacteraemia. Further information is available for CDI.

Ethnicity, deprivation and mortality

In FY 2025 to 2026:

• Black and Asian ethnic groups showed the highest age-sex standardised incidence in E. coli, Klebsiella spp., P. aeruginosa and MRSA bacteraemia

• for MRSA bacteraemia and CDI, the highest age-sex standardised incidence was observed in the White ethnic group

• for all organisms under surveillance, the highest age-sex standardised incidence rates were observed in the most deprived areas, with incidence rates rising with increasing deprivation

• the number of deaths within 30 days of diagnosis was highest for E. coli (6,281 deaths), followed by MSSA (2,821), Klebsiella spp., (2,426), CDI (1,984), P. aeruginosa (1,099), and MRSA (241)

• decreasing trends in all-cause case-fatality rate (CFR) were observed in all organisms, while the CFR, in line with previous trends, was highest for P. aeruginosa bacteraemia (23.3%) and lowest for CDI (11.6%)

• all-cause mortality rates for all organisms remained stable or saw slight decreases compared with the previous financial year, with the mortality rate ranging from 0.4 deaths per 100,000 population for MRSA bacteraemia to 10.7 deaths per 100,000 population for E. coli bacteraemia

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