Antibodies capable of neutralizing Bourbon virus were detected in pooled plasma products collected from United States donors, according to a study in the Journal of Infectious Diseases, and their concentration showed a borderline significant increase over roughly two decades. European plasma pools were largely nonreactive.
That is a different kind of finding from a confirmed case report, and the distinction is the point. The result speaks to how many Americans have encountered the virus at some point, not to how many are getting sick. Only a handful of human Bourbon virus infections have ever been confirmed in the United States.
