AbstractBackgroundHuman Circovirus 1 and 2 were recently described in a French hepatitis case and in two Chinese drug users. Because of its small size and presumable high resistance to both inactivation and removal by nanofilters, such viruses—if determined to be even pathogenic—should be considered with respect to the safety of plasma derivatives. We, therefore, investigated the prevalence and titer of these viruses in plasma pools before fractionation.Methods and MaterialsWe tested for the presence of Human Circovirus 1 and 2 by qPCR in 48 plasma pools derived from healthy donors from Europe, USA, and Japan, corresponding to more than 200,000 plasma donations.ResultsWe did not detect the presence of Human Circovirus 1 and 2 in any of the plasma pools, with a limit of detection of 300–600 genome copies per mL of plasma.ConclusionsThese results indicate that high levels of circovirus are not widely prevalent in such donations.