[Rabies].Brain Nerve. 2009 Feb; 61(2):135-44.BN
Rabies is a fetal viral encephalitis caused by the rabies virus, that is mainly transmitted through the saliva of infected domestic or wild animals. Rabies remains an important public health issue worldwide due to the prevalence of endemic dog rabies in developing countries. The epidemiological impact is particularly still high in Asian and African countries. In contrast, in the developed countries, including Japan, rabies is a re-emerging disease. The Lyssaviruses (types EBLV and ABL) and rabies virus infections via bats have recently emerged in Europe and the United States. Although the incubation period averages 1-3 months, there is no known treatment once the symptoms of rabies appear. On the basis of clinical manifestations, rabies can be classified into 2 types: furious and paralytic rabies. The former is characterized by the well-known symptoms of hydrophobia, aerophobia, and hypersalivation. However the latter type is likely to be misdiagnosed because of its similarity to Guillian-Barré syndrome and neuropsychiatric illnesses. Therefore, post-exposure treatment (PET) using a tissue-culture vaccine is the only way to prevent the disease. In the case of exposure to severe bites (WHO category III), rabies immunoglobulin (RIG) is essential for PET. Although the mechanism underlying the pathogenesis of rabies remains poorly understood, the recent technique of reverse genetics can be a useful tool for understanding rabies pathogenesis at a genetic level. Japan has been free of rabies for over 50 years because of the proper registration of domestic animals and control over their vaccinations. However, it is necessary to always remember that rabies is still a global burden as a representative of a re-emerging disease.