Where this was the case, a thorough search of records was carried out with the aim of identifying recipients of the blood and offering them counselling and testing for the virus.Where currently SNBTS is informed of any patient who is discovered to be infected with hepatitis C - and transfusion may have been the route of infection - a full investigation is carried out.Where returning blood donors from pre-1991 test positive for hepatitis C, or where patients present with hepatitis C infection which may be linked to blood transfusion, Scottish National Blood Transfusion Service (SNBTS) will investigate thoroughly the background and circumstances to these cases and will initiate lookback procedures so that any patients potentially affected can be offered counselling and testing.