A 15-year-old boy is rushed to the emergency room after suffering a tonic-clonic seizure 4 weeks after a spelunking expedition. The boy appears irritable and agitated, and his parents state that he has difficulty swallowing fluids. Lumbar puncture shows numerous lymphocytes. The patient becomes delirious, slips into a coma, and expires. At autopsy, the brain stem shows infiltrates of lymphocytes around small blood vessels and evidence of neuronophagia. Some neurons contain eosinophilic inclusions. What is the proper name for these neuronal inclusions?

Rabies is an encephalitis caused by the rabies virus, which is transmitted to humans through contaminated saliva introduced by a bite. Dogs, wolves, foxes, and skunks are the principal reservoirs, but the infection is also acquired from the bite of rabid bats, which often inhabit caves. Viral replication initiates at the site of the bite, and transport to the CNS is mediated by viral entry into peripheral nerves. Destruction of the brainstem neurons by rabies virus initiates painful spasms of the throat, difficulty swallowing, and a tendency to aspirate fluids, which has prompted the designation "hydrophobia." Encephalopathy progresses to death within 1 to several weeks. Pathologic features of rabies encephalitis include perivascular cuffing by lymphocytes, neuronophagia, microglial nodules, and "Negri bodies," which are distinctive eosinophilic, cytoplasmic inclusions in infected nerve cells. Councilman bodies (choice A) are remnants of apoptotic hepatocytes seen in acute viral hepatitis. Lewy bodies (choice C) are features of Parkinson disease.Diagnosis: Rabies