Encephalitis

 

Overview

Encephalitis is inflammation of the brain. There are several causes, including viral infection, autoimmune inflammation, bacterial infection, insect bites and others. Sometimes there is no known cause.

 

Encephalitis may cause only mild flu-like signs and symptoms — such as a fever or headache — or no symptoms at all. Sometimes the flu-like symptoms are more severe. Encephalitis can also cause severe symptoms including confusion, seizures, or problems with movement or with senses such as sight or hearing.

 

In some cases, encephalitis can be life-threatening. Prompt diagnosis and treatment are important because it's difficult to predict how encephalitis will affect each individual.

 

Symptoms

Normal vs. abnormal soft spots (fontanels) of a baby's skull

Most people with viral encephalitis have mild flu-like symptoms, such as:

Headache

Stiff neck

Fever

Aches in muscles or joints

Fatigue or weakness

 

Sometimes the signs and symptoms are more severe, and might include:

 

Confusion, agitation or hallucinations

Seizures

Loss of sensation or being unable to move certain areas of the face or body

Muscle weakness

Problems with speech or hearing

Loss of consciousness (including coma)

 

In infants and young children, signs and symptoms might also include:

 

Bulging in the soft spots (fontanels) of an infant's skull

Nausea and vomiting

Body stiffness

Poor feeding or not waking for a feeding

Irritability

When to see a doctor

Get immediate care if you are experiencing any of the more-severe symptoms associated with encephalitis. A severe headache, fever and change in consciousness require urgent care.

 

Infants and young children with any signs or symptoms of encephalitis should receive urgent care.

Causes

The exact cause of encephalitis is often unknown. Autoimmune inflammation, viral and bacterial infections, and noninfectious inflammatory conditions all can cause encephalitis.

There are two main types of encephalitis:

Primary encephalitis. This condition occurs when a virus or other agent directly infects the brain. The infection may be concentrated in one area or widespread. A primary infection may be a reactivation of a virus that had been inactive after a previous illness.

Secondary encephalitis. This condition results from a faulty immune system reaction to an infection elsewhere in the body. Instead of attacking only the cells causing the infection, the immune system mistakenly attacks healthy cells in the brain. Also known as post-infection encephalitis, secondary encephalitis often occurs 2 to 3 weeks after the initial infection.

Common viral causes

West Nile virus transmission cycle

The viruses that can cause encephalitis include:

Herpes simplex virus (HSV). Both HSV type 1 — associated with cold sores and fever blisters around your mouth — and HSV type 2 — associated with genital herpes — can cause encephalitis. Encephalitis caused by HSV type 1 is rare but can result in significant brain damage or death.

Other herpes viruses. These include the Epstein-Barr virus, which commonly causes infectious mononucleosis, and the varicella-zoster virus, which commonly causes chickenpox and shingles.

Enteroviruses. These viruses include the poliovirus and the coxsackievirus, which usually cause an illness with flu-like symptoms, eye inflammation and abdominal pain.

Mosquito-borne viruses. These viruses can cause infections such as West Nile, La Crosse, St. Louis, western equine and eastern equine encephalitis. Symptoms of an infection might appear within a few days to a couple of weeks after exposure to a mosquito-borne virus.

Tick-borne viruses. The Powassan virus is carried by ticks and causes encephalitis in the Midwestern United States. Symptoms usually appear about a week after a bite from an infected tick.

Rabies virus. Infection with the rabies virus, which is usually transmitted by a bite from an infected animal, causes a rapid progression to encephalitis once symptoms begin. Rabies is a rare cause of encephalitis in the United States.

Childhood infections. Common childhood infections — such as measles (rubeola), mumps and German measles (rubella) — used to be fairly common causes of secondary encephalitis. These causes are now rare in the United States due to the availability of vaccinations for these diseases.

Risk factors

Anyone can develop encephalitis. Factors that may increase the risk include:

Age. Some types of encephalitis are more common or more severe in certain age groups. In general, young children and older adults are at greater risk of most types of viral encephalitis.

Weakened immune system. People who have HIV/AIDS, take immune-suppressing drugs or have another condition causing a weakened immune system are at increased risk of encephalitis.

Geographical regions. Mosquito- or tick-borne viruses are common in particular geographical regions.

Season of the year. Mosquito- and tick-borne diseases tend to be more common in summer in many areas of the United States.

 

Complications

The complications of encephalitis vary, depending on factors such as:

 

The cause of your infection

The severity of your initial illness

The time from disease onset to treatment

People with relatively mild illness usually recover within a few weeks with no long-term complications.

 

Complications of severe illness

Inflammation can injure the brain, possibly resulting in a coma or death.

 

Other complications may last for months or be permanent. These complications can vary widely in severity and can include:

 

Persistent fatigue

Weakness or lack of muscle coordination

Personality changes

Memory problems

Paralysis

Hearing or vision defects

Speech impairments

Prevention

The best way to prevent viral encephalitis is to take precautions to avoid exposure to viruses that can cause the disease. Try to:

 

Practice good hygiene. Wash hands frequently and thoroughly with soap and water, particularly after using the toilet and before and after meals.

Don't share utensils. Don't share tableware and beverages.

Teach your children good habits. Make sure they practice good hygiene and avoid sharing utensils at home and school.

Get vaccinations. Keep your own and your children's vaccinations current. Before traveling, talk to your doctor about recommended vaccinations for different destinations.

Protection against mosquitoes and ticks

To minimize your exposure to mosquitoes and ticks:

 

Dress to protect yourself. Wear long-sleeved shirts and long pants if you're outside between dusk and dawn when mosquitoes are most active, and when you're in a wooded area with tall grasses and shrubs where ticks are more common.

Apply mosquito repellent. Chemicals such as DEET can be applied to both the skin and clothes. To apply repellent to your face, spray it on your hands and then wipe it on your face. If you're using both sunscreen and a repellent, apply sunscreen first.

Use insecticide. The Environmental Protection Agency recommends the use of products containing permethrin, which repels and kills ticks and mosquitoes. These products can be sprayed on clothing, tents and other outdoor gear. Permethrin shouldn't be applied to the skin.

Avoid mosquitoes. Refrain from unnecessary activity in places where mosquitoes are most common. If possible, avoid being outdoors from dusk till dawn, when mosquitoes are most active. Repair broken windows and screens.

Get rid of water sources outside your home. Eliminate standing water in your yard, where mosquitoes can lay their eggs. Common problems include flowerpots or other gardening containers, flat roofs, old tires and clogged gutters.

Look for outdoor signs of viral disease. If you notice sick or dying birds or animals, report your observations to your local health department.

Protection for young children

Insect repellents aren't recommended for use on infants younger than 2 months of age. Instead, cover an infant carrier or stroller with mosquito netting.

 

For older infants and children, repellents with 10% to 30% DEET are considered safe. Products containing both DEET and sunscreen aren't recommended for children because reapplication — which might be necessary for the sunscreen component — will expose the child to too much DEET.

 

Tips for using mosquito repellent with children include:

 

Always assist children with the use of mosquito repellent.

Spray on clothing and exposed skin.

Apply the repellent when outdoors to lessen the risk of inhaling the repellent.

Spray repellent on your hands and then apply it to your child's face. Take care around the eyes and ears.

Don't use repellent on the hands of young children who may put their hands in their mouths.

Wash treated skin with soap and water when you come indoors.

 

 

Jan Ricks Jennings, MHA, LFACHE

Senior Consultant

Senior Management Resources, LLC

 

Jan.Jennings@EagleTalons.net

JanJenningsBlog.Blogspot.com

 

412.913-0636 Cell

735.733.0509 Office

November 26, 2022

 

P.S.  Bat Masterson was born on November26, 1956.  He was born to a working-class Irish family in Quebec, but he moved to the Western frontier as a young man and quickly distinguished himself as a buffalo hunter, civilian scout, and Indian fighter on the Great Plains. He later earned fame as a gunfighter and sheriff in Dodge City, Kansas, during which time he was involved in several notable shootouts.  He died at age 67.