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National Reference Laboratory for Japanese encephalitis virus (JEV)

The Japanese encephalitis virus (JEV), like Dengue-Virus, Yellow fever virus or West Nile fever virus, belongs to the family of Flaviviruses. The genome consists of a single-stranded plus-strand RNA with a size of 11 kb (kilobases). The RNA encodes for 3 structural proteins (capsid-, membrane- and envelope protein) and 7 non-structural proteins (enzymes). The virus can be found in Japan, but also in all temperate and tropical zones of south-east Asiawhere 30.000 to 50.000 human cases are reported each year. Main focuses are rural regions with rice production and pig-breeding, but there are also infections in urban regions of developed Asian countries. Like most arboviruses, Japanese encephalitis is spread by infected mosquitoes. However, a direct transmission between humans is not possible. Domestic animals like horses, pigs and dogs can be infected by the virus, too. More than 95% of human infections proceed without any clinical symptoms, 5% of the cases develop encephalitis (very often with late neurological sequelae) and 0, 5 per cent of these cases end fatal.

So far, Japanese encephalitis virus is still exotic to Germany even though vector competent mosquitoes are present.

The NRL can perform molecular-biological (qRT-PCR) and serological tests (ELISA and VNT) within the scope of free testing or for the clarification of possible differential diagnoses.

  • Antigen- and genome detection in sample material
  • Antibody detection
  • Primary contact for federal, state and European authorities regarding Japanese encephalitis virus diagnostic and control
  • Characterization of virus isolates
  • Review, standardization and enhancement of diagnostic procedures
  • Participation and organization of ring trials (national and international)
  • Collaboration with national and international working groups and participation on research projects
  • Virus isolation and cultivation in vitro
  • Genome detection by RT-PCR (quantitative)
  • Characterization of virus strains by genome sequencing
  • Quantitative analysis of neutralizing antibodies (serum neutralization assays, plaque reduction assays, surrogate assays)
  • Serological analysis of antibodies by ELISA including differentiation of immunoglobulin classes
  • Immunofluorescence-based detection of antibodies (iIFA)
  • Sample material for establishment and validation of novel diagnostic methods (RT-PCR)