Official Statistics

Surveillance of bloodstream infections in critical care units, England: May 2016 to March 2025

Updated 16 October 2025

Applies to England

This report presents trends of bloodstream infections (BSIs) in patients in intensive care units (ICUs) in England as part of the Infection in Critical Care Quality Improvement Programme (ICCQIP). The report presents data on how often these infections occur in England, the microbes that cause them, the risk factors, and how often people die following an infection. The aim of this surveillance programme is to inform efforts to make intensive care safer for patients. This report is being published as Official Statistics in Development and is part of a collection of reports on Healthcare Associated Infections produced by the UK Health Security Agency (UKHSA).

Main points

The main messages of this report are:

• in adult units, the rate of BSIs that occurred in ICUs in financial year (FY) 2024 to 2025 was 4.7 BSIs per 1,000 bed days, this has remained largely stable except for a peak during the early stages of the COVID-19 pandemic
• in FY 2024 to 2025, the rate of intensive care unit bloodstream infections (ICU-BSIs) in adult units was 3.6 BSIs per 1,000 ICU days, similar to FY 2023 to 2024
• the most common microbes causing ICU-BSIs in adult units were Gram-negative bacteria (47.2%), followed by Gram-positive bacteria (41.4%) and Candida (9.0%)
• ICU-BSI rates were lower in paediatric and neonatal units
• in FY 2024 to 2025, the use of central vascular catheters (CVCs) was around 60% in adult units; it was higher in paediatric units (around 70%) and much lower in neonatal units (around 20%)
• the rate of BSIs linked to CVCs remained similar to FY 2023 to 2024
• approximately 2 in 7 adults with an ICU-BSI died within 30 days of diagnosis in FY 2024 to 2025

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Participation

Participation in ICCQIP surveillance is recommended for adult ICUs, as specified in NHS England’s service specifications, while it is voluntary for paediatric and neonatal units.

Of the 244 adult ICUs in England, 45.9% (112 units) reported data in financial year (FY) 2024 to 2025, the highest participation rate since surveillance began.

However, participation in paediatric and neonatal units was low, with only 13.0% of paediatric and 2.6% of neonatal units contributing data during FY 2024 to 2025. As a result, findings from these units are unlikely to be representative of national trends; they are presented in this year’s supplementary results for paediatric and neonatal units attached separately to this report.

Participation levels change year to year. For these reasons, readers should exercise caution when interpreting the results, as variation in participation can introduce potential selection bias and reduce generalisability of the findings when comparing values across different years.

For more information on participation, please see supplementary Table S1 and the quality and methodology information (QMI) report.

Rate of bloodstream infections in adult ICUs

In FY 2024 to 2025, adult units reported 4,528 positive blood cultures (PBCs), of which 2,548 (56.3%) were classified as bloodstream infections (BSIs). PBCs caused by skin commensals are classified as BSIs only if there are signs of infection and a repeat blood culture taken within 2 days is positive for that same organism. PBCs caused by other organisms are classified as BSI regardless.

Among these BSIs, 1,474 (57.8%) occurred in patients who had been in the ICU for more than 2 nights and were therefore considered ICU-BSIs, corresponding to an incidence rate of 3.6 per 1,000 ICU days (Table 1 and supplementary Table S2).

This incidence rate is similar to the previous year (3.9 per 1,000 ICU days in FY 2023 to 2024), but notably less than the peak in FY 2020 to 2021 (6.8 per 1,000 ICU days) (Figure 1 and Table 1).

Figure 1. Rates of ICU-associated bloodstream infections (ICU-BSI) per 1,000 ICU days, participating adult ICUs, England: between FY 2016 to 2017 [note 1] and FY 2024 to 2025

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

Table 1. Counts and rates of positive blood cultures (PBC), bloodstream infections (BSI) and ICU-associated bloodstream infections (ICU-BSI), participating adult ICUs, England: between FY 2016 to 2017 [note 1] and FY 2024 to 2025

Financial year	Total bed-days	Count of PBC	Rate of PBC per 1,000 bed-days	Count of BSI	Rate of BSI per 1,000 bed-days	Percentage of PBC meeting the definition of BSI	ICU days	Count of ICU-BSI	Rate of ICU-BSI per 1,000 ICU days
2016 to 2017	133,569	1,168	8.7	662	5.0	56.7%	96,419	403	4.2
2017 to 2018	354,498	2,929	8.3	1,824	5.1	62.3%	258,451	1,135	4.4
2018 to 2019	395,530	3,255	8.2	1,971	5.0	60.6%	287,358	1,216	4.2
2019 to 2020	406,248	3,043	7.5	1,901	4.7	62.5%	297,049	1,182	4.0
2020 to 2021	359,499	4,004	11.1	2,348	6.5	58.6%	275,845	1,875	6.8
2021 to 2022	380,002	3,807	10.0	2,294	6.0	60.3%	284,612	1,632	5.7
2022 to 2023	444,305	3,983	9.0	2,216	5.0	55.6%	337,591	1,400	4.1
2023 to 2024	482,772	4,128	8.6	2,346	4.9	56.8%	366,261	1,416	3.9
2024 to 2025	537,986	4,528	8.4	2,548	4.7	56.3%	411,437	1,474	3.6

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

Age and sex distribution

The median age of ICU-BSI cases in adult units during FY 2024 to 2025 was 59 years, with 75% of cases occurring in people aged between 46 and 69 years. Males accounted for 65.2% of cases (963 out of 1,476) in FY 2024 to 2025 (Figure 2). This age and sex distribution was broadly similar throughout the surveillance period.

Figure 2. Cases of ICU-associated bloodstream infection (ICU-BSI) by age group and sex, participating adult units, England: FY 2024 to 2025

Blood culture positivity

In adult units, the percentage of blood cultures that were positive decreased from 7.6% in FY 2023 to 2024 to 7.1% in FY 2024 to 2025, because of an increase in the total number of blood cultures taken (Figure 3, supplementary Table S2). Positivity peaked at 8.8% in FY 2020 to 2021, corresponding to the start of the COVID-19 pandemic, when an increase in PBCs was accompanied by a decrease in the number of total blood cultures taken. Blood culture positivity has not yet returned to pre-pandemic levels of 6.5% (FY 2019 to 2020).

Figure 3. Blood culture positivity, participating adult ICUs, England: between FY 2016 to 2017 [note 1] and FY 2024 to 2025

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

Microbiology

Organism distribution

Almost half of organisms identified in ICU-BSIs in adult units during FY 2024 to 2025 were Gram-negative bacteria (supplementary Table S8), including 222 Klebsiella species (13.7%, 5.7 per 10,000 ICU days), 168 E. coli (10.4%, 4.1 per 10,000 ICU days), 144 other Enterobacteriaceae (8.9%, 3.5 per 10,000 ICU days), 75 P. aeruginosa (4.6%, 1.8 per 10,000 ICU days), 58 Serratia species (2.7%, 1.4 per 10,000 ICU days), and 22 Acinetobacter species (3.6%, 1.4 per 10,000 ICU days). There were 136 ICU-BSIs caused by S. aureus (8.4%, 3.3 per 10,000 ICU days) and 77 caused by C. albicans (4.8%, 1.9 per 10,000 ICU days).

The organism distribution of ICU-BSIs was similar to that of all BSIs (supplementary Table S7). However, E. coli was less common in ICU-BSIs (158 cases, 10.4%) compared to BSIs (461 cases, 16.6%).

Rates of ICU-BSI by organism have stayed relatively stable since the start of surveillance in FY 2016 to 2017. However, during FY 2020 to 2021, the rates of Klebsiella species, Enterococcus species and other Gram-negative cases increased. These figures reverted to previous trends in the following years (Figure 4, supplementary Table S8).

Figure 4. Rate of ICU-associated BSIs per 10,000 ICU days, by organism group [note 2], participating adult ICUs, England, between FY 2016 to 2017 [note 1] and FY 2024 to 2025

Note 2: in Figure 4, each dark blue line represents the rate for the listed organism, while the lighter grey lines show all other organisms, for ease of comparison. This figure shows organisms aggregated in 10 key groups. A more detailed breakdown of the ‘Other Gram-negative’, ‘Candida species’ and ‘Other’ groups is presented in supplementary Tables S6 to S9.

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

Skin commensals

Skin commensals are microorganisms that reside on the human skin, normally without causing harm.

Coagulase-negative Staphylococci (CoNS) constituted only a small percentage of all organisms meeting the ICU-BSI criteria in adult units (73 cases, 4.5%, 1.8 per 10,000 ICU days, supplementary Table S8) despite being the dominant organisms isolated from PBCs (2,336, 44.9% of total, supplementary Table S6). More than 95% of CoNS and other skin commensals did not meet the BSI definition (Table 2). In most cases, this was because a repeat blood culture was not taken or reported.

Almost a quarter (24.1%, 419 out of 1,742 cases with known treatment status) of blood cultures that were positive for skin commensals and did not meet the BSI case definition received antibiotic treatment. It is therefore likely that clinicians considered these cases to be infections rather than contamination. The data presented in this report may consequently underestimate the true number of BSIs caused by skin commensals, and therefore of BSIs overall.

Table 2. Skin commensal and polymicrobial infections as a percentage of positive blood cultures (PBC), adult units, England: between FY 2016 to 2017 [1] and FY 2024 to 2025

Financial year	Count of PBC	Count of skin commensals	Percentage of PBC caused by skin commensals	Count of skin commensals which met the BSI case definition	Percentage of PBC caused by skin commensals which met the BSI case definition	Count of polymicrobial infections	Percentage of PBC with a polymicrobial infection
2016 to 2017	1,168	566	48.5%	14	1.2%	129	11.0%
2017 to 2018	2,929	1249	42.6%	35	1.2%	283	9.7%
2018 to 2019	3,255	1481	45.5%	62	1.9%	320	9.8%
2019 to 2020	3,043	1337	43.9%	51	1.7%	342	11.2%
2020 to 2021	4,004	2001	50.0%	84	2.1%	571	14.3%
2021 to 2022	3,807	1791	47.0%	86	2.3%	493	12.9%
2022 to 2023	3,983	2033	51.0%	72	1.8%	488	12.3%
2023 to 2024	4,128	2037	49.3%	82	2.0%	538	13.0%
2024 to 2025	4,528	2274	50.2%	82	1.8%	600	13.3%

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

Polymicrobial infections

Here, a polymicrobial infection is defined as multiple organisms growing from blood cultures taken on the same day. The percentage of polymicrobial infections of all PBCs remained approximately 10% during the first 4 years of surveillance, but in FY 2020 to 2021 it increased to 14.3% before decreasing to approximately 13% between FY 2021 to 2022 and FY 2023 to 2024 (Table 2).

Catheter-associated bloodstream infections

ICU-associated catheter-associated BSIs (ICU-CABSIs) are ICU-BSIs that occur after exposure to a CVC with a lack of evidence of infection at any other body site.

In FY 2024 to 2025, 21.2% of ICU-BSIs in adult units were classified as ICU-CABSIs (312 out of 1,474), corresponding to an incidence rate of 1.3 ICU-CABSIs per 1,000 ICU-CVC days (Figure 5, supplementary Table S3).

Trends in rates of ICU-CABSI in adult units were broadly similar to the ICU-BSIs incidence, described above. The rate of ICU-CABSIs varied between 1.2 and 1.6 per 1,000 ICU-CVC days during the first 4 years of surveillance, peaked at 2.1 in FY 2020 to 2021, and progressively decreased to 1.2 in FY 2023 to 2024 (Figure 5, supplementary Table S3).

Figure 5. Rates of ICU-associated catheter-associated bloodstream infections (ICU-CABSI) per 1,000 ICU-CVC days, participating adult units, England: between FY 2016 to 2017 [note 1] and FY 2024 to 2025

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

CVC utilisation

CVC utilisation refers to the number of ICU days with a CVC inserted as a percentage of the total number of ICU days.

In FY 2024 to 2025, CVC utilisation in adult units was 58.6%. CVC utilisation has remained relatively stable since FY 2022 to 2023, varying between 58.6% and 59.7%, a decrease from the peak of 65.6% in FY 2020 to 2021 (Figure 6, supplementary Table S3).

Figure 6. Central vascular catheter (CVC) utilisation in participating adult ICUs, England: between FY 2016 to 2017 [note 1] and FY 2024 to 2025

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

Regional trends

The region with the highest ICU-BSI rate in adult ICUs in FY 2024 to 2025 was the South East (5.6 ICU-BSIs per 1,000 ICU days), while the lowest rate was seen in the South West (2.7 ICU-BSIs per 1,000 ICU days) (Figure 7, supplementary Tables S4 and S5). This was compared with a national incidence of 3.6 per 1,000 ICU days (Table 1 and supplementary Table S2). For more information on regional trends, including trends by organism, please see supplementary Tables S10 and S13).

Figure 7. Rates of ICU-associated bloodstream infections (ICU-BSI) per 1,000 ICU days across NHS regions [note 3] for participating adult ICUs, England: between FY 2016 to 2017 [note 1] and FY 2024 to 2025

Note 3: in Figure 7, each dark blue line represents the rate for the listed NHS England region, while the lighter grey lines show all other regions, for ease of comparison.

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

Mortality

In FY 2024 to 2025, the all-cause case fatality rate (CFR) at 30 days from the diagnosis of an ICU-BSI was 26.9%, unchanged from FY 2023 to 2024 (26.9%). The CFR progressively increased from 25.1% in FY 2016 to 2017 to a peak of 33.0% in FY 2020 to 2021. There was a return to baseline levels in FY 2022 to 2023 (25.9%), and the CFR has broadly remained stable since (Figure 8).

A total of 4,273 (94.4%) PBC records reported for FY 2024 to 2025 by adult ICUs were successfully traced via the NHS Digital Demographics Batch Service (supplementary Table S14).

Figure 8. Thirty-day all-cause case fatality rate (CFR, %) of patients with ICU-associated bloodstream infections (ICU-BSI), participating adult ICUs, England: between FY 2016 to 2017 [note 1] and FY 2024 to 2025

Note 1: data for FY 2016 to 2017 includes data from May 2016 to March 2017 only.

Antimicrobial resistance

A study by Conroy and others was conducted to estimate the antimicrobial resistance (AMR) burden in PBCs between April 2017 and March 2023 reported by adult units to ICCQIP. The authors acquired AMR data via data linkage to the laboratory based Second Generation Surveillance System. The study showed that:

• 13% of the E. coli isolates were resistant to piperacillin/tazobactam and gentamicin, while less than 1% were resistant to meropenem
• E. coli resistance to amoxicillin/clavulanate fell during the study period (56% to 46%)
• E. cloacae resistance rose for piperacillin/tazobactam (17% to 49%) and ceftazidime (34% to 46%)
• For K. pneumoniae, resistance was 22% for piperacillin/tazobactam, 8% for gentamicin, and 2% for meropenem.
• K. pneumoniae resistance increased for piperacillin/tazobactam (14% to 26%) and amoxicillin/clavulanate (30% to 34%)
• P. aeruginosa showed 15% resistance to meropenem and 7% to gentamicin
• P. aeruginosa resistance to ciprofloxacin decreased (16% to 6%)
• E. faecium had 22% vancomycin resistance
• S. aureus had 8% meticillin resistance

The piperacillin/tazobactam EUCAST ‘R’ breakpoint for Enterobacterales was lowered in 2021, reducing the threshold for classification of resistance. The increasing trend in K. pneumoniae and E. cloacae resistance to piperacillin/tazobactam in ICUs started before FY 2021 to 2022 and is therefore not fully explained by the breakpoint reduction. However, the further increase of E. cloacae resistance in FY 2022 to 2023 may partly reflect this lower breakpoint for resistance. Further background to the impact of the breakpoint change on interpretation of AMR surveillance data can be found in the study by Conroy and others and the 2023 to 2024 ESPAUR Report.

Paediatric and neonatal units

These statistics are presented separately in the supplementary results for paediatric and neonatal units.

Discussion on ICU-BSI trends

This report summarises ICCQIP surveillance data on BSIs in adult English ICUs between May 2016 and March 2025. ICCQIP surveillance began in May 2016 with participation only open to sentinel sites; from November 2016 onwards, the invitation to participate was expanded nationwide.

Rates of ICU-BSIs and ICU-CABSIs have remained largely stable since FY 2016 to 2017, except for a steep rise that coincided with the first year of the COVID-19 pandemic. Since then, both metrics have returned to pre-pandemic levels. Most of the NHS England regions followed these national rate trends. A higher CVC utilisation, the surge in critical care occupancy rates and changes to infection prevention and control procedures, patient characteristics, and patient care during COVID-19 are possibly associated with this change. Units may also have underreported the number of patients in ICUs during this period, therefore, the actual infection rate during the early stages of the COVID-19 pandemic may have been lower than estimated. The Centers for Disease Control and Prevention (CDC) also reported a significant increase in the incidence of CABSIs during periods of high COVID-19 hospitalisations in the United States.

Adults who acquired a bloodstream infection in ICU had a median age of 59 years, with 65% being male. These demographics only partially reflect the overall ICU patient population, which has a median age of 61 years and 58% male, according to the 2023 to 2024 Case Mix Programme public report (PDF, 16MB) by the Intensive Care National Audit and Research Centre (ICNARC). It is well established that males have a higher risk of having a bloodstream infection, in both the general population (Mohus and others) and among critically ill patients (Gouel-Cheron and others).

The use of CVCs in ICUs is a known risk factor in bloodstream infections, as reported in the ‘Matching Michigan’ study. In adult units, CVC utilisation varied between 58.6% and 65.6%, with a temporary peak during FY 2020 to 2021. The European Centre for Disease Prevention and Control (ECDC) published data on healthcare-associated infections in critical care for 2016, 2017, 2018, 2019, 2020 and 2021. We report consistently lower CVC utilisation in English adult ICUs compared to Italy, Poland, and Spain. Direct comparisons of CABSI rates are challenging due to differences in how results are reported. The ECDC presents median rates across all reporting units in each country, whereas this report uses national aggregate rates. Nevertheless, England’s aggregate rates are consistently lower than the median rates in Polish, Italian, Spanish, and French units.

The incidence of ICU-CABSI has remained stable compared to FY 2023 to 2024 but has not decreased further. This suggests that current infection prevention measures are containing these infections but are not effective enough to drive a downward trend. Assessing the presence of gaps in hand hygiene, CVC care and daily review, staffing levels, staff training, and environmental cleaning might be needed to reduce the incidence. Implementing a national outlier detection and quality improvement programme could support units with higher incidence rates enhance the safety of their care.

Gram-negative bacteria comprised 47.2% of organisms associated with the ICU-BSIs in adult units, followed by Gram-positive bacteria (41.4%) and Candida species (9.0%). For Klebsiella species and Enterococcus species, the incidence of BSI associated with critical care peaked during FY 2020 to 2021. This was while overall incidence rates across England, including community-onset and ward-onset cases, remained stable, as noted in the 2023 to 2024 ESPAUR report. This discrepancy may be linked to the effects of the start of the COVID-19 pandemic, which were particularly pronounced in the critical care setting.

ICU-BSIs are associated with high mortality. This report shows that, over the surveillance period, 28.6% of people diagnosed with these infections died within 30 days. However, this figure includes deaths caused by other conditions as well as those directly linked to the infection.

ICUs have a higher incidence of BSIs compared to other hospital wards. Surveillance data can be used to identify targets and monitor quality improvement interventions. Units participating in ICCQIP benefit from a standardised tool that enables the comparison of outcomes to units across England.

Future work

Participation in this surveillance programme is voluntary and showed variation across the years. The estimated coverage of units across the country in FY 2024 to 2025 was 45.9% of total adult units in England, 13.0% for paediatric and 2.6% for neonatal units. This limits the conclusions that can be drawn for paediatric and neonatal units and the comparisons that can be made between years. We have recently introduced a simpler data collection method for adult units and are exploring automating surveillance for paediatric and neonatal units by data linkage between national audit data with laboratory results. This will also enable definition of the patient case-mix and subsequent analysis of risk factors such as ethnicity and level of deprivation on patient outcomes in intensive care.

A retrospective mixed-methods evaluation of ICCQIP has recently been conducted identifying several key recommendations. It is expected that the results of this evaluation will be published in the next year and will inform the priority areas for development of the programme.

ICCQIP will continue to conduct surveillance activities on BSIs in critical care and aims to improve the utility of outputs based on stakeholder feedback: complete this short survey to have your say.

Glossary

Bloodstream infection (BSI)

A BSI is a recognised pathogen isolated from at least one blood culture. It could also be a skin commensal that is isolated from blood cultures drawn on separate occasions within a 48-hour period, in the presence of age-specific symptoms of infection. Only one culture is required for skin commensals isolated from blood cultures taken in neonatal units. Please note that this is not synonymous with ‘sepsis’, which is variously defined and usually indicates a life-threatening response to an infection originating from any site of the body.

Central vascular catheter (CVC)

CVCs are plastic tubes inserted in a large blood vessel for treatment and monitoring purposes; however, they can increase the risk of developing a bloodstream infection. This also includes peripherally inserted central catheters and haemodialysis lines. CVCs can be short term or long term.

CVC utilisation

CVC utilisation is a percentage that indicates the proportion between:

• the total number of days on which patients who are admitted to the ICU for more than 2 nights have a CVC inserted
• the total number of days on which patients have been admitted to the ICU for more than 2 nights

Financial year (FY)

A FY is the 12-month period between 1 April to 31 March in the years stated (for example, ‘FY 2022 to 2023’ refers to 1 April 2022 to 31 March 2023).

Incidence

The number of new cases of a given medical condition in a population within a specified period of time.

Intensive care unit (ICU)

ICUs are hospital units providing intensive or high dependency care for adults, intensive care at level 3 for paediatric patients, level 2, and level 3 care for neonatal patients.

ICU-associated BSI (ICU-BSI)

A BSI is considered ICU-BSI if the patient has been in the ICU for over 2 nights after the date of ICU admission when the positive blood culture sample was taken.

ICU-associated catheter-associated BSI (ICU-CABSI)

An ICU-BSI that occurred when there was a CVC in situ at the time of sampling (or a CVC was removed in the 48 hours preceding sampling) and was not thought to be secondary to an infection at another site.

ICU-associated catheter-related BSI (ICU-CRBSI)

An ICU-BSI that occurred when there was a CVC inserted at the time of sampling (or a CVC was removed in the 48 hours preceding sampling) and there was microbiological evidence of CVC infection or clinical improvement after catheter removal.

ICU-associated central-vascular-catheter BSI (ICU-CVC-BSI)

An ICU-BSI is considered ICU-CVC-BSI if it is CVC-associated (CABSI), CVC-related (CRBSI), or both.

Micro-organism (microbe) 

Any living thing (organism) that is too small to be seen by the naked eye. Bacteria, viruses, and some parasites are microorganisms.

Polymicrobial infection

An infection is considered polymicrobial is multiple organisms are grown from the same blood culture set, or from more blood culture sets taken on the same day.

Positive blood culture (PBC)

A positive blood culture indicates that a microorganism has been isolated from the blood culture. This can either be a recognised pathogen or a skin commensal. Blood culture positivity is not synonymous with the term bloodstream infection.

Prevalence

Prevalence refers to the total number of people in a specific population who are infected with a particular infection at a given time, or over a defined period.

Skin commensals

Skin commensals are microorganisms that reside on the human skin, normally without causing harm. For the purposes of ICCQIP surveillance, these are Aerococcus species, Bacillus species other than B. anthracis, coagulase-negative staphylococci (including S. epidermidis and S. haemolyticus), Corynebacterium species, Micrococcus species, Propionibacterium species, and viridans group streptococci.

More details are available in the ICCQIP surveillance protocol and in the separate QMI report.

Data sources and methodology

Our data sources and methodology are outlined in the separate QMI report.

Background information

Patients in critical care have a higher risk of developing bloodstream infections compared to those in other wards. This is due to a combination of factors, including disease severity, comorbidity, the need to undergo invasive procedures, and medications. The prevalence of healthcare-associated infections (HCAI) is higher in critical care compared with other wards. This was highlighted by the 2023 point prevalence survey in England (PDF, 4.7MB), which found HCAI prevalence in ICUs (including paediatric and neonatal units) to be 15.9%, compared with 7.6% across all hospital wards.

The impact of HCAIs on morbidity, mortality, length of stay, and cost is well documented in Eber and others. Many interventions have been developed to reduce HCAI incidence as seen in Johnson and others, although most interventions in England have historically been focussed on reductions in the incidence of specific organisms (predominantly meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia and Clostridioides difficile infection) rather than more generally on the ICU setting or device related infections. In April 2009, a 2-year programme was launched in England called the ‘Matching Michigan’ study which aimed to reduce central line catheter related BSIs. This name referenced an earlier American study (Pronovost and others) which demonstrated a large reduction in CVC-related BSI using a range of technical and behavioural interventions. The Matching Michigan study observed a 60.0% reduction in ICU-CVC-BSI rates in adult ICUs after the intervention, with a smaller (48.8%) non-significant reduction in paediatric rates. However, the effects of the intervention were difficult to disentangle from a wider secular trend of declines in rates of BSIs associated with a range of interventions over time. Matching Michigan (Bion and others) and a parallel ethnographic study (Dixon-Woods and others) therefore identified the need for a more systematic collection and reporting of infection data.

ICCQIP, a group of professionals from across the NHS, charities, and the UKHSA, was established in 2012 to develop a national surveillance and quality improvement programme for HCAIs in the intensive care setting. An initial survey of ICUs in England was conducted to gather opinion on priorities and potential data collections as reported in the Critical Eye report (PDF, 2.31 MB). The results showed considerable support for surveillance of infections in ICUs with ICU-CVC-BSIs highlighted as the main priority. Selected sentinel units were invited to participate in May 2016. In November 2016, the invitation to participate was expanded nationwide.

Related statistics

• UKHSA also publishes quarterly reports based on data from the ICCQIP surveillance programme. The aggregate quarterly reports can be downloaded from the website of the Faculty for Intensive Care Medicine (FICM).

• Data for all cases of bacteraemia caused by MRSA, MSSA, E. coli, Klebsiella species and P. aeruginosa in any hospital ward (including ICUs) and the community is collected separately and reported regularly by UKHSA, as monthly tables and quarterly and annual reports. The most recent annual report covers data for the FY ending 31 March 2025.

• The Surveillance of Healthcare Associated Infections in Scottish Intensive Care Units programme collects data from Scottish ICUs on BSIs as well as pneumonia and CVC-related infections. The most recent report was published by Health Protection Scotland in 2019, covering data from 2018.

Further information regarding related statistics can be found in the quality and methodology information (QMI) report.

Further information and contact details

Feedback and contact information

Please complete this brief feedback survey. Your comments on this year’s report will help us improve its future versions.

You can contact us by emailing ICCQIP.surveillance@ukhsa.gov.uk.

Acknowledgements

This report was prepared by Andrea Mazzella, Matt Wilson, Rebecca Oettle, Jasmin Islam, Russell Hope, Colin Brown.

This surveillance programme would not be possible without the contribution of critical care staff across England who submit the necessary data. We also acknowledge the support and advice provided by current and previous ICCQIP oversight group members, including Thomas Hellyer (Chair) and Nicholas Brown (Deputy Chair).

Official statistics in development

These statistics are labelled as Official Statistics in Development (previously termed ‘experimental statistics’). Official statistics in development are developed under the guidance of the Head of Profession for Statistics. The goal is to develop statistics that can, in due course, be produced to the standards of the Code of Practice for Statistics. This statement provides further detail on the nature of the development and how we are continuing to assess these statistics against the Code of Practice.

While the current statistics undergo a standardised quality assurance process, there are some known limitations, as outlined in the specific data caveats section in the QMI report. This includes low participation rates for intensive care units: paediatric and neonatal units across England in the ICCQIP surveillance programme which does not give a meaningful representation of the results.

There is a need for this data to be published as they provide the national trends of annual bloodstream infections in intensive care unit patients. This data aims to inform efforts to improve patient safety in critical care settings and provide insights into organism distribution, associated factors, regional trends, and mortality. Therefore, these statistics are published as Official Statistics in Development to meet user needs, whilst being transparent on potential data quality concerns.

During the next 12 months, the ICU surveillance team at UKHSA will:

• try to negotiate data governance challenges to implement a new data collection method to improve participation from the paediatric and neonatal units
• evaluate feedback collected from key stakeholders to understand the usage of the statistics
• investigate the characteristics between responding and non-responding units to the extent that the available data allows and report on progress in the 2026 report

The results of these actions will be used to inform the decision regarding the publication status of the 2025 to 2026 ICU surveillance data as official statistics.

Our statistical practice is regulated by the Office for Statistics Regulation (OSR). The OSR sets the standards of trustworthiness, quality, and value in the Code of Practice for Statistics that all producers of official statistics should adhere to.

You can contact us directly by emailing ICCQIP.surveillance@ukhsa.gov.uk with any comments about how we meet these standards. Alternatively, you can contact OSR by emailing regulation@statistics.gov.uk or via the OSR website.