Surveillance of Infections in Blood Donors

Every donation is tested for markers of hepatitis B, hepatitis C, HIV, HTLV and treponemal (e.g. syphilis) infections. Donations are only released to the blood supply if none of these markers are detected. Additional discretionary testing may be carried out depending on a donor's relevant history (see theDonor selection guidelines), for example malaria testing if the donor has recently travelled to a country where malaria is endemic.
In 2010, the rate of infections among UK blood donors remains low with approximately 11.7 infected donations per 100,000 donations tested. During 2010, approximately 2.5 million donations were tested throughout the UK, of which 286 tested positive for a marker of infection.  Four out of every five infections detected were among new donors, who comprised just 10% of the donor population.

In the UK, hepatitis B (HBV) was the most frequently detected infection in blood donors with 91 donors testing positive for HBV, 7% of which were classified as acute infections. Markers of hepatitis C infection were detected in 80 donors, including 10 donors who had been tested in the previous three years i.e. seroconversions. The number of donors testing positive for treponemal antibodies remains at a similar rate year-on-year, during 2010, 75 donors tested positive, however, these results reflected past infections.  HIV and HTLV infections were identified in a small number of donors. A total of 18 donors tested positive for HIV infection, six of whom were seroconverters. HTLV infection was reported in 22 donors, with four infections classified as seroconversions.

Additional testing continues to be carried out for antibodies to hepatitis B core antigen (anti-HBc), antibodies to malaria and antibodies to Trypanosoma cruzi. Testing is based on risk information supplied by the donor. In England during 2010, 1.84 % of all donations were tested for past hepatitis B infection, 0.12 % for T. cruzi infections and 2.59 % for malarial antibodies. Additional testing allows additional donations to be released into the supply chain without which, donors would have to be deferred because of a potential exposure to, or past history of infection. Of the 52,570 donations tested for antibodies to malaria, 1,335 were repeat reactive, allowing 97.5 % of tested donations to be released for transfusion. There were no T. cruzi positive donations during 2010. Of the 37,210 donations tested for anti-HBc, only 46 donors were found to be positive, and removed from the donor panel.

For further information, please see our 2010 annual review entitled 'Safe supplies: Focusing on epidemiology'

Last reviewed: 4 October 2011