Japanese encephalitis

GC: n

S: WHO – http://www.who.int/mediacentre/factsheets/fs386/en/ (last access: 13 May 2017); CDC – https://www.cdc.gov/japaneseencephalitis/ (last access: 13 May 2017).

N: 1. – Japanese (adj): 1580s, Iapones; see Japan + -ese. As a noun from c. 1600; meaning “the Japanese language” is from 1828. As nouns Purchas has Iaponite (1613), Hakluyt Japonian. The destructive Japanese beetle attested from 1919, accidentally introduced in U.S. 1916 in larval stage in a shipment of Japanese iris.
– encephalitis (n): “inflammation of the brain,” 1843, from encephalo- “the brain” + -itis “inflammation.” Related: Encephalitic.
Inflammation affecting the brain may also involve adjoining structures; encephalomyelitis is inflammation of the brain and spinal cord, and meningoencephalitis is inflammation of the brain and meninges (the membranes covering the brain).
2. A mosquito-borne flavivirus infection that is the leading cause of viral encephalitis in Asia. Japanese encephalitis virus cannot be transmitted from person-to-person. The Japanese encephalitis virus is related to the viruses of St. Louis encephalitis and Murray Valley encephalitis and to the West Nile virus. Infection leads to overt encephalitis in only 1 of 20 to 1,000 cases, and a vaccine is available. Travelers to Asia from non-endemic countries have a very low risk of infection (less than 1 case per million travelers).
3. Key facts:

  • Japanese encephalitis virus (JEV) is a flavivirus related to dengue, yellow fever and West Nile viruses, and is spread by mosquitoes.
  • JEV is the main cause of viral encephalitis in many countries of Asia with an estimated 68 000 clinical cases every year.
  • Although symptomatic Japanese encephalitis (JE) is rare, the case-fatality rate among those with encephalitis can be as high as 30%. Permanent neurologic or psychiatric sequelae can occur in 30%–50% of those with encephalitis.
  • 24 countries in the WHO South-East Asia and Western Pacific regions have endemic JEV transmission, exposing more than 3 billion people to risks of infection.
  • There is no cure for the disease. Treatment is focused on relieving severe clinical signs and supporting the patient to overcome the infection.
  • Safe and effective vaccines are available to prevent JE. WHO recommends that JE vaccination be integrated into national immunization schedules in all areas where JE disease is recognized as a public health issue.

4. Signs and symptom:

  • Most JEV infections are mild (fever and headache) or without apparent symptoms, but approximately 1 in 250 infections results in severe clinical illness. Severe disease is characterized by rapid onset of high fever, headache, neck stiffness, disorientation, coma, seizures, spastic paralysis and ultimately death. The case-fatality rate can be as high as 30% among those with disease symptoms.
  • Of those who survive, 20%–30% suffer permanent intellectual, behavioural or neurological problems such as paralysis, recurrent seizures or the inability to speak.

S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=Japanese; http://www.etymonline.com/index.php?allowed_in_frame=0&search=encephalitis (last access: 13 May 2017); EncBrit – https://www.britannica.com/science/encephalitis (last access: 13 May 2017). 2. http://www.medicinenet.com/script/main/art.asp?articlekey=20163 (last access: 13 May 2017). 3 & 4. WHO – http://www.who.int/mediacentre/factsheets/fs386/en/ (last access: 13 May 2017).

SYN: JE, Japanese B encephalitis, Russian autumnal encephalitis, Russian autumn encephalitis.

S: GDT – http://www.granddictionnaire.com/ficheOqlf.aspx?Id_Fiche=8375257 (last access: 13 May 2017)

CR: dengue, encephalitis, yellow fever.