Hepatitis C in children after transfusion: assessment by look-back studies.

Look-back studies to identify paediatric patients with post-transfusion hepatitis C have been conducted at several tertiary-care hospitals in Canada. A general look-back study was conducted at the Hospital for Sick Children in Toronto for the time period December 1985 to May 1990. All patients transfused at the Hospital for Sick Children during this time period were identified from hospital Blood Bank records. Letters of notification were sent by registered mail to all recipients excluding those known to have died. In the letter anti-HCV testing was recommended. Letters were mailed to 6332 transfusion recipients; 4496 letters were delivered. Of these 146 anti-HCV-positive transfusion recipients (92 pts < 18 yrs old; 54 pts > 18 yrs old) were identified. Sixty-four of these patients were definitely transfused only during this time period. Assuming that all notified patients were tested, the minimum prevalence of new infection in this time period was 1.4%. When possible, identified patients were tested for presence of HCV RNA in the serum by RT-PCR. The proportion of patients anti-HCV positive but HCV RNA negative on one or more occasions was similar in both whole cohort and subset: approximately one-third. These data suggest that chronic hepatitis C may be less likely to develop after transfusion in children than in adults.