Clostridioides difficile (C. difficile), methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) are bacterial infections that commonly occur as a direct result of healthcare interventions (such as medical or surgical treatment), or from being in contact with a healthcare setting. They are the most well-known healthcare-associated infections (HCAIs). HCAIs pose a serious risk to patients, staff and visitors, can incur high costs for the NHS, and can cause significant morbidity to those infected. The emergence of new infections also poses a risk to patients and staff, as highlighted by the transmission of Covid-19 in health and care settings during the pandemic. As a result, infection prevention and control is a key priority for the NHS.
Public Health England defines an outbreak of acute respiratory infections as two or more laboratory confirmed cases of Covid-19, influenza or another respiratory pathogen. In care homes and hospitals, outbreaks generally peak in winter; in winter 2018-19 there was a peak of 82 outbreaks in the week starting 31 December 2018, and a peak of 15 outbreaks in hospitals in the week starting 4 February 2019. Outbreaks in winter 2019-20 followed a similar pattern, with a high of 82 outbreaks in care homes in the week starting 30 December 2019 and 13 outbreaks in hospitals in the week starting 6 January 2020.
In March 2020, the number of outbreaks increased dramatically, driven by the Covid-19 pandemic. The number of outbreaks in care homes increased from 17 in the week starting 2 March 2020 to 1,010 in the week starting 6 April 2020, and in hospitals there was a peak of 52 outbreaks in the week starting 30 March 2020. The number of outbreaks has since decreased, as NHS and care organisations have become better equipped to prevent and respond to them. However, as services resume more non-Covid activity, infection prevention and control measures remain a concern to prevent the transmission of Covid-19 in health and care settings.
It is worth noting that the data presented here does not indicate the number of individuals affected in each outbreak. No data were published between 20 May 2019 and 29 September 2019, resulting in a break in the time series.
In 2007, the levels of healthcare-associated infections, including C. difficile, became a major national concern, in particular following the Healthcare Commission’s investigation into Maidstone and Tunbridge Wells NHS Trust (Healthcare Commission, 2007). Action to address these problems was far-reaching and included new legislation as well as focussed investment, regulation and performance monitoring against targets. Following this focus in 2007, the total number of C. difficile infections decreased year-on-year to reach a low of 13,362 cases in 2013/14.
In 2014/15 there was a slight increase in C. difficile infections from the previous year, a 4% increase for hospital-onset cases and an 8% increase for community-onset cases. Since then, the number of C. difficile infections has fluctuated. In 2018/19, there were 4,201 hospital-onset cases and 8,074 community-onset cases.
In 2007, the level of healthcare-associated MRSA infections also became a major national concern, similar to C. difficile. The reduction in the number of MRSA cases has followed a broadly similar trajectory to that of C. difficile. Between 2007/08 and 2013/14, there was an 81% reduction in total cases (a 90% reduction in hospital-onset cases and a 70% reduction in community-onset cases). Despite this reduction, the number of MRSA cases increased slightly in 2015/16 and has fluctuated since then. In 2018/19, there was a 2% decrease in hospital-onset cases and a 7% decrease in community-onset cases.
Enhanced surveillance of E. coli bacteria has been mandatory for NHS acute trusts since June 2011. Following a worrying increase in E.coli infections, the NHS Patient Safety Strategy includes a goal to decrease healthcare associated Gram-negative bloodstream infections by 25% by 2021 and halve them by 2024. E. coli represents 55% of all Gram-negative bloodstream infections, and reducing the number of E. coli infections is an important safety issue. Preventing bloodstream infections would also reduce the need to prescribe antimicrobials, which is a key way of reducing the rise in antibiotic resistance.
Between 2012/13 and 2018/19, the total number of E. coli infections increased by 34%, from 32,309 to 43,242. The number of community-onset cases increased by 44%, but the number of hospital-onset cases only increased by 1%. The increase is likely to reflect higher rates of blood culture testing as awareness of sepsis risk has increased.
About this data
National COVID-19 surveillance reports:
Acute respiratory infection incidents are based on situations reported to Public Health England Health Protection Teams. A confirmed outbreak of acute respiratory infections is defined as two or more laboratory confirmed cases (Covid-19, influenza or other respiratory pathogens) linked to a particular setting.
C. difficile, MRSA and E. coli data:
The bacterial infections are deemed to be hospital-onset if the following rules are met:
- the location where the specimen was taken is given as 'acute trust' or is not known;
- the patient was either an 'In-patient', 'Day-patient', in 'Emergency assessment' or the patient type is not known;
- the patient's specimen date is on, or after, the third day of the admission (for MRSA and E. coli) or the fourth day of the admission (for C. difficile), where the day of admission is day one.
If the above rules are not met, then cases are deemed to be community-onset.