All You Need To Know About Encephalitis

All You Need To Know About Encephalitis

Encephalitis refers to an infection of the brain and is more commonly referred to as brain fever. ‘ It is a serious illness associated with high morbidity and death rates. Recently, encephalitis was in the news, after a lot of deaths were reported in children suffering from encephalitis in Uttar Pradesh. However, it should be known that this is not a recent phenomenon and encephalitis has been prevalent in many parts of India for several decades, with high rates of death being reported.

What Causes Encephalitis?

The most common causes are viral infections such as herpes simplex and Japanese B viruses. Herpes simplex virus (HSV) is transmitted via droplets, casual contact or sometimes through sexual contact. While, Japanese B encephalitis (JE) virus is transmitted via mosquito bites (Culex species). Japanese B Encephalitis is the most common cause of encephalitis in Asia and in India. The name Japanese encephalitis came from Japan, where the first case of JE was reported in 1871. Today, JE infection occurs in many countries.

New-born babies and infants are more susceptible to develop encephalitis and it is more common in those with poor immunity, those with cancers and amongst older people

Encephalitis can affect any age group. However, children are more prone to develop this chronic illness. Among children, new-born babies and infants are more susceptible to develop this infection. Encephalitis is also more common in people with poor immunity, in people with cancers and in older people.

Common Symptoms

Patients with encephalitis display common symptoms including headache, fever, general weakness, and fatigue. As the infection worsens, patients may become drowsy and even unconscious, Seizures (fits) and paralysis may occur in several patients, Speech disturbances, difficulty in swallowing and breathing difficulty may occur in some patients with encephalitis.


Any patient presenting with fever, headache, and impaired consciousness should be suspected to have encephalitis illness, At this stage, a patient needs to undergo a detailed neurological examination. A brain scan, especially MRI of the brain is carried out to look for specific parts of the brain affected with different types of encephalitis. In Japanese encephalitis, the thalamus and basal ganglia are more commonly affected. On the other hand, in HSV encephalitis, temporal and frontal lobes of the brain are more commonly affected.

Lumbar puncture is done to further study the nature of the infection. For this, a small amount of cerebrospinal fluid (CSF) is removed through a needle inserted in the lower back and sent for analysis. This test can help in identifying the exact nature of infection in many cases. Further, EEG (electroencephalography) is also conducted to learn of the presence of seizures and characterize its type and frequency.

Treatment And Outcome

Encephalitis is a critical illness and the patients should be treated and monitored in the ICU. Initial treatment includes maintaining the vital parameters such as pulse, blood pressure, and respiration within normal limits. If there is respiratory difficulty, oxygen should be provided. In some cases, mechanical ventilation may also be required.

Specific antiviral medicine called ‘acyclovir’ is available for HSV encephalitis and it should be started as soon as possible. However, there is no specific antiviral drug for treating Japanese encephalitis infection but antiepileptic drugs should be given to patients with seizures.

Adequate care should also be taken regarding nutrition and hydration. Patients may need feeding via nasogastric tube (which extends from nose to stomach), as they are unable to swallow. Hence, glucose and saline drips may be given based on the condition. A patient may need to undergo treatment for about 7 to 10 days in ICU. At the same time, he/she needs to take antiviral medicines for about 14 days.

Japanese encephalitis causes death in about 30 per cent of those infected despite best medical treatment. Similar death rates can be seen with other serious cases of encephalitis too. And those who survive may have several long-term complications such as deafness, epilepsy, poor scholastic performance and weakness of the arms or legs.

Can Encephalitis Be Prevented?

There is a saying, ‘prevention is better than cure’ and this couldn’t be truer for encephalitis. As treatment does not help a large number of patients with this illness, it is a good idea to prevent it. Thus, there are vaccines available for preventing JE encephalitis and all children should receive the vaccine in areas where Japanese encephalitis is common. Adequate hygiene should be maintained to prevent mosquito breeding. Measures to prevent mosquito bites such as full arm/leg clothing, mosquito repellents, and mosquito nets also help.

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