Abstract
In the report by Minamoto et al. in this issue of the Journal, we have a striking reminder of the importance of pathogenic retroviruses, a special class of molecular pirates, both to individuals and to the public health in general.1 What we can now say on the basis of the current article and other reports2 is that we must carefully consider the prevalence of single or multiple retroviral infections in certain populations that otherwise appear well and may serve as blood donors. The 20th century has seen unprecedented scientific progress, and so it is ironic that as the century . . .