Fatal Encephalitic Borna Disease Virus 1 in Solid-Organ Transplant Recipients

Borna disease virus 1 (BoDV-1; species Mammalian 1 orthobornavirus) causes progressive meningoencephalitis, mainly in horses and sheep. Evidence of BoDV-1 infection in humans is limited.1,2 However, after the identification of a bornavirus transmitted by exotic pet squirrels — the variegated squirrel bornavirus 1 (species Mammalian 2 orthobornavirus)3 — the zoonotic potential of mammalian bornaviruses should be considered. Here, we report evidence of donor-transmitted BoDV-1 infection occurring in three solid-organ transplant recipients, two of whom died.