Japanese encephalitis is an infectious disease caused by viruses. It is most common in Southeast Asia, China, and India and can be fatal if left untreated. However, there is a vaccination against this tropical disease, which is recommended to every traveler to Asia by the Tropical Institute. Young children and the elderly in particular are at risk of severe complications from Japanese encephalitis.
What is Japanese encephalitis?
Japanese encephalitis is a tropical disease that occurs mainly in East and South Asia. Heavily affected areas include most of India and the southern part of the PRC. It is a viral disease that in many cases causes very mild symptoms or can remain symptom-free because it does not break out at all. However, one out of every 250 people becomes seriously ill and develops encephalitis, an inflammation of the meninges. It is accompanied by symptoms such as impaired consciousness, high fever, muscle pain and severe headaches. Children are also characterized by diarrhea and vomiting. If Japanese encephalitis is not fatal, it often leaves permanent damage.
Causes
Japanese encephalitis is caused by viruses that live in farm animals. Wild birds and pigs are particularly likely candidates; they carry most of the viruses. Occasionally they are also found in horses or bats. They are ultimately transmitted by mosquitoes, which pick up the virus from the farm animal and introduce it into humans through their bite. The incubation period of the Japanese encephalitis virus is 5-15 days, after which an outbreak of Japanese encephalitis may occur. The risk of infection for tourists is very low; the rural population in the areas at risk is primarily affected. The rate of new infections with Japanese encephalitis is also related to the life cycle of mosquitoes, as well as to the rainy seasons, which are crucial for the survival and death of vector animals in this zone of the world.
Symptoms, complaints, and signs
Japanese encephalitis is usually mild or causes few or no symptoms. However, in two out of 250 cases, infected individuals develop severe health problems that are fatal in nearly 30 percent of cases. Many survivors suffer permanent neurological damage after recovery. In general, Japanese encephalitis causes flu-like symptoms with fever, chills and headache. In a severe course, meningitis presents with headache, muscle and neck pain, neck stiffness and fatigue in addition to fever. Gastrointestinal complaints and increased sensitivity to light and noise are also typical. If encephalitis also occurs, the initial high fever is followed by nervous system deficits. Many patients suffer from confusion, clouding of consciousness and changes in behavior. Physically, encephalitis is manifested by seizures, paralysis, reflex disorders and muscle tremors. As it progresses, the patient falls into a coma. Symptoms of severe Japanese encephalitis appear within a short time and become more severe over a period of a few days. The fever normally decreases only after seven to ten days of illness. In a severe course, the individual symptoms can lead to the death of the patient.
Course of the disease
Following infection, the Japanese encephalitis virus is in most cases killed by the body’s immune system. No development of the disease occurs, and the individual does not sustain permanent damage. After the incubation period of 5-15 days, there may also be only very mild symptoms that would hardly differ from a severe flu. They disappear on their own after a few days and weeks and also leave no damage. The cases of concern are those in which the symptoms become severe and start with high fever, headache and pain in the muscles. Within a few hours and days after the first symptoms of the disease, disturbances of consciousness appear, indicating the involvement of the meninges. There may also be the expression of other neurological symptoms. If Japanese encephalitis is not treated, it can be fatal. Even with treatment, this can sometimes be the case.At best, the patient survives Japanese encephalitis and sustains only some permanent damage.
Complications
This encephalitis is a very serious disease. If there is no treatment, the patient may die from this disease in the worst case. Likewise, irreversible consequential damages are possible. To avoid possible discomfort and complications, vaccination should always be carried out before traveling. Those affected suffer from a strong fever and headaches. These can also spread to other regions of the body and cause pain there. Furthermore, without treatment, there is severe paralysis throughout the body and a stiff neck. Complete unconsciousness may also occur and the sufferer will suffer from a stiff neck. The quality of life is significantly reduced by Japanese encephalitis and everyday life is restricted. The affected person’s ability to cope with stress also decreases considerably as a result of this disease. Japanese encephalitis cannot be treated directly. Only the symptoms are limited. No particular complications occur. However, the duration of this infection cannot be predicted. Likewise, it is possible that the affected person will be infected again even after successful treatment. If treatment is initiated early, there is usually no decreased life expectancy.
When should you see a doctor?
If abnormalities and changes in health sensations are noticed a few days after receiving a mosquito bite, a physician should be consulted. There is cause for concern if there are skin changes, unusual wound formation, or abnormalities in the lymph. A physician should be consulted as soon as malaise, internal weakness or a feeling of illness occur. If symptoms similar to those of influenza are noticed, they should be observed. In case of headache, increased need for sleep, fever or sweating, a doctor should be consulted. Fatigue and a lack of concentration as well as loss of appetite should be examined and treated. If neurological abnormalities occur shortly thereafter, medical attention must be sought immediately. In case of gait unsteadiness, memory problems or dysfunction, the affected person needs medical help. A visit to the doctor is imperative, as permanent impairment and a diminished quality of life may result. Shaking limbs, muscle weakness, a stiffness of the body or a general lack of performance should be examined and treated. Paralysis and cramps already indicate severe progression of the disease. A visit to the doctor is necessary to prevent long-term damage. In severe cases, without medical treatment, the affected person may die prematurely. In acute cases, an ambulance service must be alerted. First aid measures must be initiated until the latter arrives.
Treatment and therapy
Currently, Japanese encephalitis cannot be specifically treated. Because it is viral, research into an active agent is also hampered, since it is not bacterial and classic methods (e.g., antibiotics) are therefore unlikely to be effective. In the case of Japanese encephalitis, the course of the disease is mainly intervened symptomatically. For example, it is possible to reduce the patient’s fever with medication in order to prevent permanent damage or death. Furthermore, respiration and circulation are supported, which can be impaired by the involvement of the brain. In addition, it may be useful to prevent secondary infection by isolating the patient, as such infection could be fatal.
Follow-up
To fully cure Japanese encephalitis, comprehensive care and follow-up are required. Treatment is aimed at relieving symptoms. It is very important for patients to take the medications prescribed by their doctors correctly. So far, there are no medicines for the direct treatment of the disease, but sufferers should still consult a doctor. Self-medication at home carries the risk of complications. A specialist, on the other hand, can identify the risk at an early stage and do something about it. Within the framework of a targeted, intensive therapy, the disease can be cured well with timely intervention.Treatment is generally performed on an inpatient basis to ensure close monitoring. After therapy, follow-up care focuses on further control examinations. Even after hospitalization, patients should continue to take care of themselves. To rule out secondary infections, meticulous hygiene must be maintained. This includes the use of disinfectants. Certain safety measures should protect patients from infection during the recovery phase. Only when the symptoms of the disease have subsided as a result of regular medication can those affected give up their disease-induced isolation. Depending on the severity of the life-threatening disease, however, the recovery phase may take somewhat longer.
Outlook and prognosis
Japanese encephalitis can lead to numerous complications as well as premature death of the affected person without adequate medical care. Although the infectious disease mostly occurs in Southeast Asia or India, it can still be transmitted to the local population by vacationers or other travelers. Due to the drastic course of the disease, there is the possibility of a protective vaccination. Since just under 30 percent of those who contract the disease have a fatal outcome, this should be used in the event of a planned trip. If a vaccination has taken place, an infection and thus an outbreak of the disease is unlikely. The difficulty of Japanese encephalitis lies in the risk of confusion with influenza. If, as a result, the diagnosis and thus the medical treatment take place at an advanced stage of the disease, the prognosis worsens. This can lead to lifelong consequential damage such as restricted mobility, paralysis or headaches. There is also the possibility of the onset of unconsciousness. If consciousness is disturbed, intensive medical care is necessary. Lesions of the brain are possible that are irreversible. If the patient receives prompt and comprehensive medical care, there is a possibility of complete recovery. Symptomatic treatment takes place, which is created according to the patient’s individual symptoms. Regression of symptoms is achieved through the administration of medications.
This is what you can do yourself
Although there are still no effective drugs for the treatment of Japanese encephalitis, sufferers should in no case try to monitor the course of the disease at home by themselves. Professional medical therapy and care are essential to adequately respond to potential serious complications. Thus, patients with Japanese encephalitis enter inpatient care and follow the instructions of physicians and staff. In the absence of appropriate medications, nurses simply monitor the body’s vital functions, such as circulation, heart rate, and the patient’s breathing. The patient spends most of the inpatient stay in a resting position and takes care through hygienic and quarantine measures not to become infected with secondary infections. Contact with other persons is only possible if they have undergone thorough disinfection and appropriate safety measures are applied. During inpatient treatment, the patient must ensure that he or she obtains sufficient energy and nutrients through his or her diet. If sufficient food intake is not possible due to physical weakness or other reasons, the patient will receive intravenous liquid nutrition. The patient must inform the medical staff of any change in his or her condition to avoid complications of Japanese encephalitis.