Horses, sheep, cattle, rodents, birds, reptiles, and humans serve as natural hosts.

The ICTV proposed the creation in 1996 of the family Bornaviridae along with the genus Bornavirus (today Orthobornavirus).

[2] Proteins of orthobornaviruses that have been characterized: In the Mononegavirales order, Bornaviridae is one of only two families with viruses that replicate in the nucleus.

Genomic analysis found a previously unknown orthobornavirus in a contact squirrel and in brain tissue from the three men, the researchers reported, and it is the "likely causative agent" in their deaths.

[10] Since behavioral disease has been studied in BoDV-1 infected animals like rhesus monkeys, tree shrews, and rats, BoDV-1 has also been hypothesized to be associated with humans psychiatric conditions such as schizophrenia and affective psychoses.