Risk assessment for Japanese encephalitis vaccination

Abstract

Japanese encephalitis (JE) is the most commonly diagnosed viral encephalitis in Asia. JE is caused by a virus called JE virus (JEV), a member of the genus Flavivirus, family Flaviviridae, and is transmitted by Culex mosquitoes. Neutralising antibody to JEV protects against JE, and can be induced by vaccination. JE is a potential threat to travellers to endemic areas, which are most of South and Southeast Asia and some Pacific Islands. The risk of JE can be expected to increase with increasing mosquito exposure and time spent in regions and seasons of active transmission. JE is very rare in travellers, but mortality is high, around 1 in 3, and there is a high rate of lasting neurological damage. JE can therefore be a profoundly life changing event for a traveller. Travellers and their healthcare providers need to balance the low risk of disease against the very high severity of disease if it does occur. In order to make an informed decision, the severity of JE disease should be carefully explained to travellers to Asia.

Generation and characterization of Japanese encephalitis virus expressing GFP reporter gene for high throughput drug screening

“…Japanese encephalitis virus (JEV) is a mosquito-borne virus that belongs to the genus Flavivirus in the family Flaviviridae , which includes many other important human pathogens such as yellow fever virus (YFV), West Nile virus (WNV), tick-borne encephalitis virus (TBEV) and dengue virus (DENV) ( Buescher et al, 1959 ; Ellis et al, 2000 ). JEV is mainly epidemic in the Asia Pacific region, putting more than 3 billion people at the risk of JEV infection ( Turtle and Driver, 2018 ). It is estimated that more than 67,900 Japanese encephalitis cases caused by JEV occur worldwide each year and the mortality rate is as high as about 20%–30% ( Campbell et al, 2011 ; Griffiths et al, 2014 ; Hills et al, 2010 ).…”

Japanese Encephalitis Virus NS1′ Protein Antagonizes Interferon Beta Production

“…Japanese encephalitis (JE) has a mortality of 10%-50%, and approximately half of JE survivors have severe neurological sequelae (Turtle and Solomon 2018). Although vaccines against JEV have been used for many years, more than 50,000 meningoencephalitis cases and approximately 15,000 deaths are reported each year (Ginsburg et al 2017;Turtle and Driver 2018).…”

‘More than devastating’—patient experiences and neurological sequelae of Japanese encephalitis§

“…Any risk assessment for JE vaccination must, therefore, carefully consider the proposed itinerary and season of travel, as well as any predisposing conditions that might increase the risk of developing JE following infection with the virus, such as immunocompromise, extremes of age, pregnancy and conditions compromising the blood brain barrier, as well as the prospect of repeated visits 3 , 34 . Our third patient’s arteriovenous malformation may have predisposed to JE through compromise to the blood–brain barrier.…”