Epidemiology Unit

Monitoring infections in blood, tissue and organ donors, and transfusion recipients

Who we are

The joint NHS Blood and Transplant (NHSBT) / UK Health Security Agency (UKHSA) Epidemiology Unit comprises a small team of epidemiologists and public health specialists working with scientific and clinical colleagues across both NHSBT and UKHSA (previously known as PHE).

The unit was established in 1995 to monitor infections in blood donors and transfusion recipients. Over time the role of the unit has expanded and we are now responsible for monitoring infections in blood, tissue and organ donors, and transfusion recipients. Data from the four UK blood services are collated and analysed by the unit to produce surveillance reports and inform/evaluate policy changes relating to infection risk.

What we do

The Epidemiology Unit monitors infection in blood, tissue and organ donors, and transfusion recipients. The unit collates and reports national epidemiological data on:

  • Bloodborne infections among donors
  • The associated risk of transmission through transfusion and transplant

Data are collected from blood centres throughout NHSBT, the Welsh Blood Service, the Irish Blood Service and the Northern Ireland Blood Transfusion Service. Data from Scotland are collected by the Scottish National Blood Transfusion Service (SNBTS), passed to the surveillance schemes and included in national analyses.

The unit manages a series of national surveillance schemes, data from these schemes are used to assess and improve blood, tissue and organ safety. These schemes include:

  • Infections in blood donors: monitored through donation testing and the collection of information about identified infected donors.
  • Infections in tissue donors (including stem cell and cord blood donors): monitored in a similar way to blood donors.
  • Reported post-transfusion infections: among transfusion recipients in England and Wales which forms part of SHOT (Serious Hazards of Transfusion).
  • Emerging infections: relevant reports from various sources are collated and reported on a monthly basis or as necessary. More information on these reports is available here.
  • Transfusion Microbiology Epidemiology Review (TMER): looking for evidence of transmission of CJD via blood transfusion.

What we work towards

The information collected through our surveillance schemes contributes to maintaining a safe supply of blood, tissues and organs through:

  • Informing donor selection criteria
  • Monitoring trends in infections
  • Following up any reported post-transfusion infections

Blood donors are a well characterised low risk group with around 2 million donations screened each year for HBV, HCV, HIV, HTLV, HEV and syphilis. The information collected also contributes to our understanding of the epidemiology of blood borne infections, and there is potential for following up infected donors. This could provide additional information to public health specialists working to reduce infections in the general population, through prioritising population groups for interventions and delivery of care.

Blood borne viruses unit (BBVU)

The joint NHSBT / UK Health Security Agency (UKHSA) epidemiology unit works closely with the Blood Borne Viruses Unit (BBVU) to improve blood safety.

Latest annual report - Safe supplies 2022: monitoring safety in donors and recipients

Annual report archive

For information on, or data from, any of our surveillance schemes or reports, please email epidemiology@nhsbt.nhs.uk

SHOT (Serious Hazards of Transfusion) Annual Reports 

View annual reports