MRSA and C. difficile quarterly update

19 March 2010

The Health Protection Agency (HPA) has today published a quarterly epidemiological commentary on trends of MRSA (meticillin-resistant Staphylococcus aureus) bloodstream infections and C. difficile (Clostridium difficile) infections from October 2007 to December 2009.

MRSA bloodstream infections

Overall there has been a 59% decrease in the number of MRSA episodes reported during the surveillance period in England, from 1092 cases in Q4/2007 (October to December) to 444 cases during the same time period in 2009.  Among trust-apportioned episodes - patients presumed to have been infected while admitted to the trust - there has been a 64% decrease since Q4/2007, from 654 episodes to 237 episodes in the same period in 2009. In comparison with the previous quarter (Q3 - July to September 2009) there has been no significant change.

The number of non-trust apportioned episodes ('all other episodes') has decreased by 53% from 438 episodes in Q4/2007 to 207 episodes in Q4/2009. There has also been a 8% decrease since the previous quarter (Q3/2009), when 226 episodes were reported.

Counts of trust-apportioned and all other episodes of MRSA bacteraemia, October - December 2007 to October - December 2009

Recording cases as trust and non-trust apportioned helps to provide a clearer picture of where infections are likely to have been acquired. Comprehensive infection control requires initiatives by a range of non-acute trust facilities, across the whole health economy, including district general hospitals, nursing establishments and residential homes.

The proportion of MRSA cases among the different age groups remains unchanged with 48% of cases being seen in the 75 and older age group.

Analysis of the causes of MRSA bacteraemia

The commentary also includes a trend analysis of the causes of patients' MRSA and information about patient risk factors, from data voluntarily completed in the surveillance scheme.  Owing to the voluntary nature of the collection of this data, interpretations should be made with caution.

Analysis of the data from April 2006 to December 2009, found that almost half (44%) of MRSA cases acquired while patients were staying in acute Trusts were attributable to lines, this included 19% from central device catheters, 18% from peripheral venous cathetar and 7% from other lines. A further 40% were caused as a result of infections at another body site, mainly skin and soft tissue infections.

Clostridium difficile infections

The incidence of trust-apportioned and all other episodes of Clostridium difficile infection have decreased between Q4/2007 (October to December) and the same period in 2009.

Between Q4/2007 and Q4/2009, there has been a 58% decrease in the counts of trust-apportioned episodes and a 41% decrease in the number of all other episodes.

Counts of trust-apportioned and all other episodes of CDI, Oct - Dec, 2007 (Q4/2007) to Oct - Dec, 2009 (Q4/2009)

The rates of infection with Clostridium difficile across all age groups remain constant over time in relation to each other.  The older age groups continue to have the highest risk of infection, with cases in males and females aged 85 years and above nearly double those for 75 to 84 year olds.

Monitoring repeat episodes of C. difficile infection
When patients become infected with C. difficile, they are treated with a course of antibiotic therapy, the majority of these patients recover, but symptoms reoccur for a small percentage of patients. Known factors that increase the risk of recurrent infection include old age, continued use of antibiotics and a prolonged stay in hospital. 

HPA surveillance looked at the proportion of patients who had a repeat episode (the guidelines require all positive specimens taken 28 or more days apart to be reported). It was found that 13% of patients who had one episode of C. difficile infection had repeat episodes reported in a 180 day follow up period.  The majority of second positive specimens are taken between 28 and 50 days after the first. 44% of these patients who have had two positive specimens reported within 180 days, had stayed in hospital for the entire duration of time between these tests being conducted.

Dr Christine McCartney, Executive Director for the HPA's Healthcare Associated Infection and Anti-Microbial Resistance Programme, said:

"We must commend the NHS for implementation of programmes which have resulted in the continuous reduction in the numbers of these infections.

The HPA continues to provide advice and support for the various NHS initiatives which have led to the increasing awareness of HCAIs for good antibiotic stewardship, high standards of cleanliness and staff training."

Notes for editors
For further information on healthcare associated infections and to view the agency's latest mandatory surveillance reports and quarterly commentary on epidemiology visit the website below: http://www.hpa.org.uk/HPA/Topics/InfectiousDiseases/InfectionsAZ/1191942126522/

To download a copy of the agency's Annual Healthcare Associated Infections Report please visit the website http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1252326221795?p=1249920576124

Change to mandatory surveillance publication format
The HPA has been working to provide MRSA bloodstream and C. difficile infection counts in a more timely fashion, with the aim of benefiting those concerned with infection control and performance management from the Trust level to the Department of Health.

As of November 2009 the Health Protection Agency changed the way it publishes MRSA and C. difficile data, publishing monthly data on the first Wednesday of each month.

This commentary is the second new format epidemiological commentary published by the HPA on the trends in healthcare-associated infection mandatory reports.  These commentaries include age and sex profiles of patients with the infections, the patterns of disease across various hospital demographics such as patient provenance and treatment specialties.

For further information on this press release please contact the Health Protection Agency's Centre for Infections press office on:

Kate Swan  020 8327 7097
Alexandra Baker  020 8327 7098
Louise Brown  020 8327 7080
Eleanor Bunch 020 8327 7751

Last reviewed: 19 March 2010