Extraneural organ involvement in human rabies

Human rabies is a fatal encephalomyelitis. After the development of the cen tral nervous system infection, there is centrifugal spread of the rabies vi rus to extraneural (systemic) organs. With histochemical staining and local ization of rabies virus antigen (RVA) with immunoperoxidase staining, we ha ve examined tissue sections of organs from 14 postmortem pediatric and adul t cases of human rabies acquired in Mexico and the People's Republic of Chi na. RVA was found in nerve plexuses in multiple organs, including the gastr ointestinal tract. RVA was observed in muscle fibers of the heart, tongue, and larynx. RVA frequently was observed in the adrenal medulla with an asso ciated inflammatory reaction. Minor salivary glands of the tongue contained RVA and major salivary glands showed RVA in plexuses, but not in either ac ini or ducts. Epithelial cells of the tongue and taste buds were occasional ly infected. RVA was observed in hair follicles of the skin and rarely in p ancreatic islets. The infection of extraneural organs was sometimes, but no t always, associated with an inflammatory reaction. These findings indicate that centrifugal spread of rabies virus to extraneural organs occurs frequ ently in human rabies.