Hepatitis C test results do not justify claim of test equivalence nor of prolonged seroconversion

In a recent case report in Vox Sanguinis , Alvarez et al . describe what they call a ‘prolonged hepatitis C virus seroconversion in a blood donor’ [1]. They tabulate four samples tested between 13 December 2000 and 20 April 2001. The first three samples were hepatitis C virus (HCV) polymerase chain reaction (PCR)-only positive, but the last sample was also positive for antibody to HCV. The claim of prolonged seroconversion is based upon the time span between the first and the fourth sample, i.e. 128 days. However, this assertion is only justified for the time span between the first and the last PCR-only positive (the third) sample, as the anti-HCV enzyme immunoassay (EIA) may have become positive a few days later. This time span is 72 days and therefore well within the limits of our experience. Similarly, any differences between HCV RNA and antigen seroconversion have occurred before obtaining the first sample. Therefore, no conclusion concerning a difference or a lack of difference between HCV RNA and HCV-antigen seroconversion times can be drawn from this case report.