Letter from Dr. V. E. Mitchell, The Leicester Royal Infirmary, to Linda Frith, Cutter, regarding Hepatitis B infection of a patient following open heart surgery where 2 units of whole blood and 6 units of platelet concentrate were given during surgery and 51 units of Koate HT Factor VIII concentrate (batch 50R004) for 10 days prior to and following surgery. Also includes a record of the complaint in the Cutter Complaints Log.