Neurotropic virus

A neurotropic virus is a virus which is capable of infecting nerve cells, or which does so preferentially.

Related terms include neuroinvasive (capable of entering or infecting the central nervous system, for example from the peripheral nervous system), and neurovirulent (capable of causing disease within the nervous system). By avoiding the bloodstream, neuroinvasive viruses are able to evade to a great extent the usual immune response and entrench themselves in the host body's nervous system. The most common neuroinvasive viruses are rabies, which has both high neuroinvasiveness and high neurovirulence, and herpes simplex virus, which has low neuroinvasiveness and high neurovirulence. Others, like poliovirus, can spread neurally, but primarily spread by hematogenous dissemination (that is, via the blood system). Neurotropic viruses that cause acute infection include Japanese Encephalitis, Venezuelan Equine Encephalitis, and California encephalitis viruses; polio, coxsackie, echo, mumps, measles, influenza, and rabies as well as diseases caused by members of the family Herpesviridae such as herpes simplex, varicella-zoster, cytomegalo and Epstein-Barr viruses. Those causing latent infection include herpes simplex and varicella-zoster viruses. Those causing slow virus infection include measles, rubella and JC viruses, and retroviruses such as human T-lymphotropic virus 1 and human immunodeficiency virus.

Prions, which are not viruses but instead are infectious proteins, cause transmissible spongiform encephalopathy such as kuru and Creutzfeldt-Jakob disease that resemble a slow virus infection.