Japanese encephalitis(JE) is a viral disease that infects animals and humans. It is transmitted by mosquitoes in humans causing inflammation of the membranes around the brain. Japanese encephalitis is a leading cause of viral encephalitis in Asia generally spread from western pacific region in east to Pakistan in west and from Korea in north to Papua New Guinea in south.
Japanese encephalitis is a disease caused by a flavi virus that affects the membranes around the brain. Generally infections caused by Japanese encephalitis virus are mild (fever and headache) or without apparent symptoms, but sometimes 1 in 200 infections can result in severe disease characterized by rapid onset of high grade fever, headache, neck stiffness, disorientation, coma, seizures, spastic paralysis and death.
Japanese encephalitis has an incubation period of 5 to 15 days and the majority of infections are asymptomatic i.e. only 1 in 250 infections develop into encephalitis.
Intial symptoms include:
- A high temperature (fever) of 38C (100.4F) or above
- Feeling sick
- Muscle pain
In rare cases, these initial symptoms last for a few days and then develop into serious symptoms:
- Seizures (fits)
- Changes in mental state, which can range from mild confusion to being very agitated or falling into a coma
- Uncontrollable shaking of body parts (tremor)
- Losing the ability to speak
- Muscle weakness
- Abnormally tense muscles (hypertonia)
- Movement problems, such as shaking, stiffness, slowness of movement or paralysis
- Difficulties in controlling the movements of the eyes
- Difficulties in controlling the muscles of the face
Japanese encephalitis is caused by a flavi virus. This type of virus can affect both animals and humans. The virus is passed on to humans from animals through an infected mosquito.
Risk factors includes:
- The region you visit
- The time of year you visit
- The activities you do
Blood tests: To know the antibodies present in the blood.
Lumbar puncture: It is also done to check for antibodies in CSF and spinal fluid.
Scans: In case of brain encephalitis:
- A computerized tomography (CT) scan, which takes a series of X-rays of body at slightly different angles to produce a clear image of the inside of body
- A magnetic resonance imaging (MRI) scan, which uses a strong magnetic field and radio waves to produce detailed images of the inside of body
There is no specific treatment for Japanese encephalitis, supportive treatment is provided. Measures can be taken to control symptoms and prevent complications from developing.
It can lead to mild complications like:
- Uncontrollable shaking of the hands
- Changes to personality
- Muscle weakness and twitching in the arms and hands.Moderate disability can take the form of:
- Mild learning difficulties
- Paralysis of a single limb
- Weakness on one side of the body