Japanese encephalitis | |
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Other names | Japanese B encephalitis |
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The geographic distribution of Japanese encephalitis (dark green) | |
Specialty | Infectious disease |
Symptoms | Headache, fever, vomiting, confusion, seizures[1] |
Usual onset | 5 to 15 days after infection[1] |
Causes | Japanese encephalitis virus (spread by mosquitoes) |
Diagnostic method | Blood or cerebrospinal fluid testing[2] |
Prevention | Japanese encephalitis vaccine, avoiding mosquito bites[2] |
Treatment | Supportive care[1] |
Prognosis | Permanent neurological problems occur in up to half of survivors[2] |
Frequency | 68,000[2] |
Deaths | 17,000[2] |
Japanese encephalitis (JE) is an infection of the brain caused by the Japanese encephalitis virus (JEV).[3] While most infections result in little or no symptoms, occasional inflammation of the brain occurs.[3] In these cases, symptoms may include headache, vomiting, fever, confusion and seizures.[1] This occurs about 5 to 15 days after infection.[1]
JEV is generally spread by mosquitoes, specifically those of the Culex type.[2] Pigs and wild birds serve as a reservoir for the virus.[2] The disease occurs mostly outside of cities.[2] Diagnosis is based on blood or cerebrospinal fluid testing.[2]
Prevention is generally achieved with the Japanese encephalitis vaccine, which is both safe and effective.[2] Other measures include avoiding mosquito bites.[2] Once infected, there is no specific treatment, with care being supportive.[1] This is generally carried out in a hospital.[1] Permanent problems occur in up to half of people who recover from JE.[2]
The disease primarily occurs in East and Southeast Asia as well as the Western Pacific.[2] About 3 billion people live in areas where the disease occurs.[2] About 68,000 symptomatic cases occur a year, with about 17,000 deaths.[2] Often, cases occur in outbreaks.[2] The disease was first described in Japan in 1871.[2][4]