Two blood donations, which were initially thought to be safe, showed evidence of the virus on subsequent testing. Bio Products Laboratory, the sole manufacturer of blood products in England and Wales, has told hospital consultants and pharmacists that they are withholding the batch as a precautionary measure.
The products affected include Factor VIII for haemophiliacs, immunoglobulin injections for travellers and people suffering from immunosuppression, and supplies of albumin which are given to burns patients. Hepatitis C causes a mild acute form of hepatitis.
Richard Walker, chief executive of BPL, based in Elstree, Hertfordshire, wrote to consultants and pharmacists that manufacturing processes would eliminate Hepatitis C but the stock would be quarantined to 'avoid any unnecessary public concern'.
Dr Harold Gunson, medical director of the National Blood Authority, said the contamination was revealed after samples from two donors were found to contain antibodies to Hepatitis C. Both had given blood before, and samples from the original donations were tested and found to contain a small amount of antibody. The virus was only discovered in 1989 and testing of donations introduced in September 1991. The tests' sensitivity had increased over the past year, Dr Gunson said. He said there was negligible risk to patients.
BPL was informed of the contamination before the batch of plasma products affected had been distributed.