Winners of globalization: dengue viruses and Japanese encephalitis virus-Diseases in neurology

Arboviruses are transmitted by arthropods, more than 100 of them are human pathogens and many of the arboviruses have neurotropic characteristics such as dengue viruses (DENV) and Japanese encephalitis virus (JE-V). Both DENV and JE-V belong to the genus Flavivirus. Climatic changes, food imports from the tropics and travel behavior have also increased the number of cases of diseases caused by tropical or subtropical viruses in Europe. Due to the close degree of relationship of the flaviviruses, coinfections with several arboviruses can occur. The DENV and JE-V are mosquito-borne infections caused by the genus Aedes spp. In cases of involvement of the central nervous system, the virus often reaches the brain via the blood-brain barrier. The DENV is a single-stranded RNA-positive virus with four known serotypes, DENV-1 to DENV-4. The DENV infections are usually asymptomatic and are known as classical dengue fever, the more severe courses are dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), usually with fatal outcome. Both DHF and DSS are classical second infections. A vaccination is not approved in Germany but has been approved for endemic regions since 2015. The course of an infection with JE-V initially runs characteristically and it is only characterized by encephalitis a few days later. For the JE-V a vaccine is approved even in Germany.