The HPA has been managing, on behalf of the Department of Health, the mandatory surveillance of Staphylococcus aureus bacteraemia in England since April 2001.

The following aggregated data ("quarterly lab returns") are also collected as part of this surveillance scheme:

• Total blood culture sets examined (a sample arising from a single venepuncture, irrespective of the number of bottles tested)
• Total number of positive blood cultures (all positive results for bacterial growth, including repeat specimens and contaminants)

Positive blood cultures from the same patient within 14 days of the initial culture are considered to be part of the original episode and should not be reported. Duplicate reports, more than 14 days apart should be reported as these are considered to be a separate episode.

Mandatory MRSA bacteraemia surveillance scheme

The surveillance of Meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia has been mandatory for all NHS acute trusts in England since April, 2004. In October 2005 this surveillance was enhanced to collect patient-level data. This scheme has been developed by the HPA at the request of the Department of Health.

By comparison to the quarterly laboratory returns, enhanced surveillance involves collecting patient details for each MRSA bacteraemia episode such as NHS number, hospital number, date of birth, and sex, as well as information concerning the patient's location, date of admission, consultant specialty, and care details at the time the blood sample was taken. Trusts have access to a web-based surveillance system, where these details on each MRSA bacteraemia episode can be entered.

The HPA produces tables of counts of MRSA bacteraemia on a monthly and annual basis. Every quarter the data collected in the enhanced surveillance is used to produce epidemiological commentaries with the aim of contributing to a better evidence base regarding risk factors for infection.

The results of the mandatory MRSA bacteraemia enhanced surveillance scheme:

• MRSA bacteraemia tables - Monthly: Acute Trust results by month for a 13 month period.
• MRSA bacteraemia tables - Annual: Acute Trust results by quarter and by financial year. April 2006 onwards.
• MRSA bacteraemia commentaries - Quarterly: Commentary on trends over a period of 9 quarters.

The future dates for publication of mandatory surveillance data are available via the publication schedule pages.

NHS Acute Trusts can obtain further information about the scheme by emailing mandatory.surveillance@hpa.org.uk.