What is viral encephalitis?
Encephalitis is the medical term for inflammation of the brain, a potentially life-threatening condition that can occur in people of all ages but which is fortunately very rare. It is caused by an infection with a virus. The course of viral encephalitis varies. Most people infected with viral encephalitis have only mild or no symptoms, and the illness doesn't last long. However, serious cases can have headache, high fever, lethargy, convulsions, delirium, coma, and or death. The survivors may have significant mental impairment, including loss of memory, inability to speak coherently, lack of muscle coordination, paralysis, hearing or vision defects.

Encephalitis can be of 2 types:

Primary
This form is due to a direct viral invasion of the brain and spinal cord. The virus can be sporadic or epidemic. The most common sporadic form, herpes simplex encephalitis, may start as a minor illness with headache and fever, followed by more serious symptoms. Epidemic varieties are commonly caused by mosquito-borne viruses. The major types of mosquito-borne encephalitis that infect people in the United States are eastern equine encephalitis, western equine encephalitis, St. Louis encephalitis, La Crosse encephalitis and, more recently, West Nile encephalitis.

Secondary (post-infectious)
This form follows or occurs with a viral infection in another part of the body such as chickenpox, measles (rubeola), mumps, rubella (German measles) or polio. The cause of encephalitis in some secondary cases may be a hypersensitivity reaction - an overreaction of the immune system to a foreign substance.

Primary encephalitis is the most serious kind of encephalitis, but the secondary form is more common. But because of the milder nature of secondary encephalitis, doctors see more cases of primary encephalitis.

Contagiousness
Brain inflammation itself is not contagious, but any of the various viruses that cause encephalitis can be. Of course, just because a child gets a certain virus does not mean that he or she will develop encephalitis. Still, to be safe, children should avoid contact with anyone who has encephalitis.

To avoid tick bites:
* Limit kids' contact with soil, leaves, and vegetation.
* Have kids wear long-sleeved, light-colored shirts and long pants when outdoors.
* Check your kids and your pets frequently for ticks.
Duration
For most forms of encephalitis, the acute phase of the illness (when symptoms are the most severe) usually lasts up to a week. Full recovery can take much longer, often several weeks or months.

What causes viral encephalitis?
Mosquitoes are responsible for the transmission of encephalitis from small creatures, usually birds and rodents, to humans. Birds who live near bodies of standing water, such as freshwater swamps, are susceptible to infection with an encephalitis virus. When a bird is infected with encephalitis, it carries high levels of the virus in its blood for a short time before recovering from the infection and developing immunity to the disease. If a mosquito feeds on an infected bird, the mosquito will become a lifelong carrier of the disease. The mosquito will transmit the infection to the next bird it feeds on, which will in turn give it to more mosquitoes. Usually, this transmission pattern cycles through without serious impact on either creature and without affecting humans. This is partly because mosquitoes' primary hosts are birds and small mammals, and they bite humans only as a second choice. However, sometimes environmental disasters, unusual weather or other climate changes cause an increase in the number of infected birds, as well as mosquitoes that feed on both birds and humans. Under these conditions, humans may be affected. The risk of occurrence is highest during the warm months when birds and mosquitoes are more in numbers.

What are the signs and symptoms of viral encephalitis?
These include:

Drowsiness
Confusion and disorientation
Seizures
Sudden high fever
Severe headache
Nausea and vomiting
Tremor
Bulging in the soft spots (fontanelles) of the skull, in infants
Stiff neck.

Warning signs and symptoms include altered level of consciousness. In infants, the key symptoms are a stiff neck and a bulging in the soft spots of the skull (fontanelles). In older children, the initial symptoms may be a severe headache and sensitivity to light. In adults, mental disturbances may be more prominent as an initial symptom.

What is the treatment?Because viruses that cause encephalitis usually don't respond to antibiotics, treatment mainly consists of rest and a healthy diet including plenty of fluids to let the immune system fight the virus. In some cases, physical and speech therapy may be needed as part of treatment. To treat herpes simplex encephalitis, an antiviral agent such as acyclovir may be prescribed in the early stages of the illness. In some cases an anticonvulsant medication is prescribed. Anti-inflammatory drugs or medications that reduce pressure within the skull may also be used.

Prevention
Encephalitis cannot be prevented except to try to prevent the illnesses that may lead to it. Encephalitis that may be seen with common childhood illnesses can be largely prevented through proper immunization. Have your kids immunized according to the immunization schedule recommended by your doctor. Kids should also avoid contact with anyone who already has encephalitis.

In areas where encephalitis can be transmitted by insect bites, especially mosquitoes, kids should:
* Avoid being outside at dawn and dusk (when mosquitoes are most active).
* Wear protective clothing like long sleeves and long pants.
* Use insect repellent.
Also, all standing water around your home should be drained, including buckets, birdbaths, flowerpots, and tire swings because these are breeding grounds for mosquitoes.

 

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