title: Prospective investigation of transfusion transmitted infection in recipients of over 20 000 units of blood. TTI Study Group.
abstract: OBJECTIVE
  To follow up recipients of 20 000 units of blood to identify any transmissions of infections through blood transfusion.
  
  
  METHODS
  Follow up study of recipients of transfusion.
  
  
  METHODS
  22 hospitals in north London.
  
  
  METHODS
  Adult patients who had recently been transfused.
  
  
  METHODS
  Patients had further blood samples taken at 9 months that were tested for markers of hepatitis B and C and HIV and human T cell leukaemia/lymphoma virus type I or II (HTLV) infections. Recent infections were distinguished from pre-existing infections by comparison with blood samples taken before transfusion.
  
  
  RESULTS
  9220 patients were recruited, and 5579 recipients of 21 923 units of blood were followed up. No transfusion transmitted infections were identified. The incidence of transfusion transmitted infections was 0 in 21 043 units (95% confidence interval for risk 0 to 1 in 5706 recipients) for hepatitis B; 0 in 21 800 units (0 to 1 in 5911 recipients) for hepatitis C; 0 in 21 923 units (0 to 1 in 5944 recipients) for HIV; and 0 in 21 902 units (0 to 1 in 5939 recipients) for human T cell leukaemia/lymphoma virus. Three patients acquired hepatitis B during or after hospital admission but not through transfusion; 176 (3%) had pre-existing hepatitis B infection. Sixteen (0.29%) patients had hepatitis C, and five (0.09%) had human T cell leukaemia/lymphoma virus.
  
  
  CONCLUSIONS
  The current risk of transfusion transmitted infections in the United Kingdom is very small, though hospital acquired infections may arise from sources other than transfusion. A considerable proportion of patients have pre-existing infections.
authors.affiliation: National Blood Service, London and South East Zone, North London Centre, London NW9 5BG.
authors.forename: F A
authors.initials: FA
authors.lastname: Regan
authors.forename: P
authors.initials: P
authors.lastname: Hewitt
authors.forename: J A
authors.initials: JA
authors.lastname: Barbara
authors.forename: M
authors.initials: M
authors.lastname: Contreras
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017848:Blood-Borne Pathogens; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission*; D006509:Hepatitis B / Q000453:epidemiology / Q000635:transmission*; D006526:Hepatitis C / Q000453:epidemiology / Q000635:transmission*; D006801:Humans; D015994:Incidence; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000453:epidemiology / Q000635:transmission*; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D065227:Transfusion Reaction