Background: In 1996, the Danish National Board of Health recommended hepatitis C virus (HCV) lookback to identify recipients of blood components from donors found to be positive since the implementation of anti-HCV screening in 1991.
Study design and methods: The aim was to accumulate results of the lookback at a national level and to describe the morbidity of the infected recipients. Records of transfusion were identified for at least 10 years back, and recipients still alive were tested for hepatitis C. Those with positive results were referred for clinical evaluation.
Results: A total of 150 anti-HCV-positive Danish donors had donated blood to 1018 transfusion recipients, of whom 288 (29%) were still alive. Because of age, malignancy, or other severe diseases, 118 (41%) of these were not contacted. Of 157 recipients screened for HCV, 128 (82%) were anti-HCV positive on enzyme-linked immunosorbent assay, and 88 (56%) were HCV RNA positive. Among the HCV RNA-positive recipients, symptoms were present in 38 percent (25/66 reported), elevated alanine aminotransferase was found in 53 percent (41/77 tested), and cirrhosis was found in 11 percent (6/54 biopsied). Treatment with interferon alpha was initiated in 23 patients, corresponding to 26 percent of HCV RNA positive recipients.
Conclusion: Among tested recipients in the Danish HCV lookback, most were anti-HCV positive and more than half were still viremic. The morbidity was considerable, and one-fourth of viremic recipients entered treatment.