ABSTRACT
Among the diseases of viral origin, rabies is unique in its distribution and range of victims since it can afflict all warm-blooded animals. The interaction between the virus and the host population has facilitated the survival of the disease. The rabies virus (RV) has not changed in any significant way and has been capable of taking advantage of conditions suited to the continuance of rabies. Infection by RV is invariably lethal in the absence of protective immune response which, however, can contribute to the pathogenesis of rabies. Proinflammatory cytokines might affect, directly or indirectly, the levels of neurotrophins, growth factors, neurotransmitters and neurotoxins in the brain by activating glia, neurons, and vascular and immune cells. Although understanding of the bases for neuronal dysfunction and neuronal death during RV infection has progressed, no fundamental abnormality has been identified so far.