Japanese encephalitis is a type of infection and inflammation of the brain caused by a virus that is transmitted through mosquito bites, especially in rural areas of most of Asia.  X Trusted Source National Health Service (UK) Visit source First of all, mosquitoes spread this virus through bites to animals and birds, then transmission can continue to humans through the bites of these animals. This viral infection cannot be transmitted between humans. Most sufferers only show mild flu-like symptoms, although some cases require emergency treatment. Symptoms of Japanese encephalitis are difficult to identify, but you need to keep an eye on the infected person (usually children) in case the disease gets worse.
Recognizing the Symptoms of Japanese Encephalitis
Watch for flu-like symptoms. Most people with Japanese encephalitis show no visible or very mild symptoms and do not last long. In addition, the symptoms resemble those of the flu, including fever, fatigue, lightheadedness, and sometimes vomiting. Therefore, cases of Japanese encephalitis are difficult to identify because they do not appear or resemble other diseases.
It is estimated that less than 1% of people infected with Japanese encephalitis virus (JEV) have obvious symptoms.
If a person exhibits symptoms of Japanese encephalitis, the incubation period (the time between initial infection and the appearance of symptoms of the disease) is usually 5-15 days.
Watch out for high fever. Although the visible symptoms of JEV infection are often few or none, the chance of developing a dangerous case of Japanese encephalitis is 1 in 250 cases, which often starts with a severe fever. A high fever is the body’s defense mechanism to slow or stop the spread of viruses and bacteria. However, if the temperature exceeds 39 degrees Celsius in adults or 38 degrees Celsius in children, the patient is at risk for brain damage. The high fever and increased inflammation in the brain caused by JEV can trigger a variety of other serious and life-threatening symptoms.
Once the symptoms of Japanese encephalitis are evident, usually in children who have a weak immune system, the chance of death is 30%.
Mild cases of Japanese encephalitis can raise the temperature by as much as 2 degrees Celsius. However, in severe cases, the increase can be up to 5 degrees Celsius or more.
Note the stiff neck. Like other types of infection that affect the brain and/or spinal cord (eg meningitis), Japanese encephalitis can cause a stiff neck. The neck may suddenly feel stiff and difficult to move in any direction. However, if the neck is flexed (by touching the chin to the chest), there will be sharp pain, aches, or like being electrocuted.
When the spinal cord becomes inflamed, the muscles closest to the spine tense up to protect it. This is called guarding or splinting . Therefore, the neck muscles will be difficult to touch and feel like they are having a spasm.
Medication, massage, or chiropractic will not treat a stiff neck from Japanese encephalitis, meningitis, or other infections of the central nervous system.
Watch for mental or behavioral changes. Other effects triggered by brain inflammation and high fever are mental changes, such as disorientation, confusion, difficulty focusing, and even being unable to speak. Behavioral changes are often interconnected, accompanied by irritability and/or an inability to control temperament, as well as being aloof and avoiding social contact.
It usually takes a few days from the time the symptoms of Japanese encephalitis begin until the disease becomes more severe and serious.
The mental and behavioral changes associated with severe JEV infection can mimic those of stroke or Alzheimer’s disease. The patient will change from a normal healthy human being to a severe mental person and in poor physical condition.
Recognize the symptoms and signs of Japanese encephalitis so that treatment can be carried out immediately and increase the chances of recovery.
Look for neurological changes. When Japanese encephalitis gets worse, which is characterized by increased swelling and a high temperature, the nerves in the brain begin to damage and die. If this happens, neurological symptoms will start to become obvious, such as violent shaking of body parts (tremors), muscle paralysis or weakness, difficulty walking and grasping, and reduced coordination (looking sloppy).
Muscle weakness and paralysis usually starts in the limbs (hands and feet) and spreads gradually throughout the body. However, sometimes the symptoms of the disease can start from the face.
A quarter of people who survive severe Japanese encephalitis (about 70% of total patients) develop permanent neurological and/or behavioral disorders and disabilities.
Be prepared for convulsions. The development of a serious attack of Japanese encephalitis can end in convulsions, which are triggered by swelling of the brain, high fever, and electrical disturbances/discharges in the brain’s neurons. Seizures may be accompanied by fainting, shaking, muscle spasms, jaw clenching, and sometimes vomiting or foaming at the mouth.
Seizures triggered by encephalitis can resemble epilepsy, but are much more life-threatening because they cause brain damage.
Children with encephalitis are more likely to have seizures than adults because they have smaller brains and are more susceptible to pressure and increased temperature.
Once the seizures have started, the patient will usually pass out or even fall into a coma.
Preventing Japanese Encephalitis
Vaccinate your body. According to the World Health Organization (WHO), which is the world’s health organization, the safest and most effective way to prevent Japanese encephalitis is by injecting a vaccine. The four main types of vaccines used to prevent JEV infection are inactivated mouse brain-derived vaccines, inactivated Vero cell-derived vaccines, live attenuated vaccines, and recombinant live vaccines. Get vaccinated about 6-8 weeks before visiting Asia to give your body time to build up lots of protective antibodies.
The most widely used vaccine to prevent JEV infection is the live attenuated SA14-14-2 vaccine made in China.
The locations that have the highest risk of transmitting Japanese encephalitis are in the interior of Japan, China, and Southeast Asia. Make sure you have been vaccinated before visiting these areas to reduce the risk of contracting it.
The Japanese encephalitis vaccination is usually given in several doses over several weeks or months.
Remember that encephalitis can be caused or exacerbated by vaccinations (all types of vaccines) due to an allergic reaction to vaccine ingredients.
Avoid mosquito bites. Another form of protection against JEV infection is the control and prevention of mosquito bites because these animals are the main cause of Japanese encephalitis. Therefore, avoid or drain all standing water to prevent mosquito breeding, and always use insect repellent that contains a chemical called DEET (Autan, Soffell). In addition, use mosquito nets to protect the bed from mosquitoes, and do not leave the house at dawn and dusk because this is when mosquitoes are most active and congregate in the air.
Most mosquito repellent products can last up to six hours. Some mosquito repellents are even waterproof.
DEET products should not be used in children younger than two months of age.
Mosquito repellent is also available in natural forms, namely lemon oil and eucalyptus oil.
Preventing mosquito bites while traveling will also reduce the risk of contracting other serious diseases, such as malaria and West Nile viruses.
Wear protective clothing. In addition to mosquito repellent and mosquito nets, you should also wear protective clothing when traveling in Asia, especially in rural areas. Therefore, wear a long-sleeved shirt and light cotton gloves (popular in many Asian countries) to protect the entire arm and palm. To protect your feet, wear long pants along with socks and shoes when traveling, especially when walking in marshy or grassy areas.
Usually Asia has very warm and humid temperatures most of the year. So, choose pants and long-sleeved shirts that are easy to breathe so you don’t overheat.
However, don’t forget that mosquitoes can bite through clothing. So, spray it with a mosquito repellent too, just in case. Do not spray mosquito repellent containing permethrine on your skin.
Avoid high-risk outdoor activities. If you are in Asia, stay away from outdoor activities that increase the risk of being bitten and infected by mosquitoes, such as camping, hiking and exploring by motorbike or bicycle. These activities are not only common in rural areas, but also expose you to risks. mosquito bite. Opt for tours in a covered car (eg bus tours) when in outback areas and wear protective clothing, as described above.
If you must sleep outdoors while in rural Asia, make sure you cover your tent or residence with mosquito netting coated with a strong insecticide.
While you are out of town, sleep only in hotel rooms where the windows and doors are protected by cloth or tightly perforated wire gauze.
Don’t travel to Asia. This method also prevents you from contracting Japanese encephalitis, although it is quite drastic. Do not travel to Asian countries that have had Japanese encephalitis (unfortunately, most Asian countries have had this disease). This step is easy to do for ordinary travelers. However, those who work or have relatives in Asia are unlikely to follow this advice. In reality, the risk of transmitting this disease is very small. It is estimated that less than one per million travelers traveling to Asia contract Japanese encephalitis each year.
It’s best not to visit inland areas if you’re traveling in Asia, especially farm areas where there are lots of pigs and cows.
The people most at risk of contracting JEV are those who live and work in rural areas, especially children under 15 years of age.
If possible, avoid traveling in Asian countries during the rainy season (the times vary from country to country) because this season the mosquito population increases and threatens your safety even more.