Infectivity of pre-seroconversion donations: an analysis of lookback exercises in The Netherlands, 2000-2006

Blood can be infectious if it is donated shortly before infection with hepatitis B virus (HBV), hepatitis C virus (HCV) or human immunodeficiency virus (HIV) becomes detectable. Lookback exercises may detect infection in recipients of pre-seroconversion donations. This study provides an analysis of the Dutch lookback exercises in the years 2000 through 2006.

All lookback procedures, triggered by 50 repeat donors seroconverting for HBV (n=32), HCV (n=3), HIV (n=14) and HBV + HIV (n=1), were analysed. Recipients and archived samples of the 96 implicated donations were tested.

For 76 donations, a stored sample was available for HBV, HCV, or HIV PCR testing, revealing two HBV-DNA-positive pre-seroconversion donations. Ninety-three lookback procedures were initiated, to which 91 of 93 hospitals responded. In 87 of 91 cases, the implicated blood product had been administered. In 39 of 87 cases, the recipient was tested, revealing one HIV and two HBV infections. The HIV infection was considered pre-existent. The two HBV-positive patients received components from the donation of which the repository sample tested positive for HBV-DNA. Components of the second HBV-positive pre-seroconversion donation had not been administered.

Among 39 recipients of pre-seroconversion donations, 2 (5%) were found HBV infected by transfusion. The labour-intensive lookback procedures did not reveal any conclusive transmissions additional to the infections detected by PCR testing of repository pre-seroconversion samples.