{"id":14637,"date":"2022-03-10T13:08:15","date_gmt":"2022-03-10T02:08:15","guid":{"rendered":"https:\/\/mvec.mcri.edu.au\/?post_type=references&p=14637"},"modified":"2026-03-26T18:08:06","modified_gmt":"2026-03-26T07:08:06","slug":"benh-viem-nao-nhat-ban","status":"publish","type":"references","link":"https:\/\/mvec.mcri.edu.au\/vi\/references\/japanese-encephalitis\/","title":{"rendered":"B\u1ec7nh vi\u00eam n\u00e3o Nh\u1eadt B\u1ea3n"},"content":{"rendered":"
<\/p>\n

What is it?<\/h2>\n

Japanese encephalitis<\/span> (JE)<\/span> is<\/span> a rare but potentially serious disease<\/span> caused by infection with<\/span> <\/span>Japanese encephalitis virus<\/span><\/span><\/em> (JEV)<\/span>.<\/span> JEV<\/span><\/span> is a<\/span> flavivirus<\/span> (other <\/span>flaviviruses cause diseases <\/span>including <\/span><\/span>yellow fever<\/span><\/span><\/span><\/a>, <\/span>dengue<\/span><\/a> and Murray Valley encephalitis<\/span>)<\/span>. <\/span>S<\/span>pread to humans through mosquito bites<\/span><\/span>,<\/span> JEV<\/span> is a leading<\/span> cause of vaccine-preventable encephalitis (brain inflammation) in Asia and the Western Pacific.<\/span><\/span><\/p>\n

What to look for?<\/h2>\n

Most people infected with JEV do not develop symptoms or develop mild symptoms <\/span>only<\/span>. <\/span>However, a<\/span>pproximately 1 in 250 people <\/span>infected<\/span> will experience se<\/span>vere clinical illness. <\/span>If s<\/span>ymptoms <\/span>develop,<\/span> they will <\/span>occur<\/span> 5 to 15 days after exposure<\/span> and <\/span>can include fever, <\/span>diarrhoea<\/span> and rigors (episodes of shivering and feeling cold).<\/span> Fe<\/span>a<\/span>tures of severe illness<\/span> with encephalitis<\/span> include <\/span>h<\/span>eadache, confusion, vomiting, <\/span>paralysis<\/span>, <\/span>seizures<\/span>,<\/span> neck stiffness<\/span>,<\/span> disorientation<\/span> and coma<\/span>. <\/span>JE has<\/span> a<\/span> mortality rate of 20 to 30%, with permanent neurological disability occurring in 30 to 50% of survivors.<\/span><\/span><\/p>\n

How is it transmitted?<\/h2>\n

JE is a zoonotic disease and can spread to humans when a mosquito bites an infected animal (mostly water birds or pigs) and then bites a human. <\/span>It cannot be transmitted from person to person, or through eating pork or pig pro<\/span>ducts. Horses can be infected with JEV; however, they cannot transmit the disease further.<\/span><\/p>\n

When JE occurs during pregnancy, infection can be transmitted to the unborn baby.<\/span><\/p>\n

In most temperate areas of Asia and Australia, JEV is transmitted mainly during the warmer months. In the tropics and subtropics, transmission can occur year-round but often intensifies during the rainy season when mosquito numbers are greater.<\/span><\/p>\n

Epidemiology<\/h2>\n

There are an estimated 100,000 clinical cases of JE globally each year, resulting in approximately 25,000 deaths.<\/span> JE is most common across Asia and the Western Pacifi<\/span>c. In the 1990s, cases were reported in the Torres Strait Islands and in Cape York (mainland Australia).\u00a0 In 2022 and 2023, cases occurred in the Murray and Riverina regions of south-eastern Australian states.<\/span><\/p>\n

Where JEV is present, people with increased exposure to mosquitoes are at higher risk of infection, particularly those spending time outdoors or working with pigs. Children under 5 years of age and older people who are infected with JEV are at higher risk of more severe illness, including encephalitis.<\/span><\/p>\n

Prevention<\/h2>\n

Physical barriers<\/h3>\n

Preventing mosquito bites with physical barriers is the most effective way to avoid infection with JEV. <\/span>Exposure to mosquito bites can be prevented <\/span>by:<\/span><\/span>\u00a0<\/span><\/p>\n