Epidemiology Unit

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

Who we are

The joint NHS Blood and Transplant (NHSBT) and 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. The role of the unit has expanded over time and we are now responsible for monitoring infections in blood, tissue and organ donors, and transfusion recipients.

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:

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

Data from the 4 UK blood services (NHSBT, Welsh Blood Service, Northern Ireland Blood Transfusion Service and the Scottish National Blood Transfusion Service) is collated and analysed by the unit to produce surveillance reports and inform or evaluate policy changes relating to infection risk.

The unit manages a series of national surveillance schemes. Data from these schemes is 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.
  • Infections in deceased organ donors: monitored in a similar way to blood donors.
  • Reported post-transfusion infections: monitoring investigations among transfusion recipients from the four UK blood services, as the national infection co-ordinator as part of Serious Hazards of Transfusion (SHOT).
  • Emerging infections: relevant reports from various sources are collated and reported on a monthly basis or as necessary.
  • Transfusion Microbiology Epidemiology Review (TMER): looking for evidence of transmission of CJD via blood transfusion.

The unit manages the UK Blood Donor Surveys to help assess the impact of donor selection policy changes including FAIR. We also manage the HTLV National Register in collaboration with Imperial College Healthcare NHS Trust, consisting of donors with HTLV and HTLV specialist clinic attenders, to inform public health about onset and progression of HTLV associated disease.

What we work towards

Our work helps to maintain a safe supply of blood, tissues and organs by:

  • 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 1.8 million donations screened in the UK each year for markers of HBV, HCV, HIV, HEV, syphilis, and HTLV in new donors.

The information we collect 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.