Transmission of Neurotropic Viruses by Transplantation

Abstract

Despite efforts to screen donors of organs and tissues, neurotropic viruses have been transmitted through solid organ transplantation. Transplanted viruses vary as to family and character but have certain traits in common. West Nile virus, a species in the genus Flavivirus, and lymphocytic choriomeningitis virus, the type species in the genus Arenavirus, are both zoonotic viruses for which humans are incidental hosts. Both result most commonly in asymptomatic or minimally symptomatic infections in immunocompetent humans. Thus donor screening dependent upon a history of recent symptomatic disease will be inadequate to detect risk of these infections. Rabies, the type species in the genus Lyssavirus, is also zoonotic. Human rabies infections lead almost invariably to fatal central nervous system disease. Human rabies infections are rare in North America and Europe, and suspicion of rabies depends on a history of animal bite. Infected humans may present late in the disease course and distant in time from the animal bite that provided the source of infection. A high suspicion for rabies should be maintained for any potential donor who exhibited signs or symptoms of central nervous system disease prior to death. Human infection with polyomavirus hominis 2 (JC) virus or polyomavirus hominis 1 (BK) virus, two species in the genus Polyomavirus, leads to silent latent infection that is virtually ubiquitous by early adulthood. Although both can be associated with neurologic disease in immunocompromised hosts, disease associated with either virus is more likely to result from reactivation of virus already latently infecting the transplant recipient. Nonetheless since human infection is not universal, the possibility of transmission via transplanted organs or tissues exists.