Encephalitis (en-sef-uh-LIE-tis) is a kind of brain inflammation. A viral infection is the most prevalent cause, although there are others. Encephalitis frequently produces relatively minor flu-like symptoms, such as a fever or headache, or no symptoms at all. The flu-like symptoms might be more severe at times. Encephalitis can also result in muddled thinking, convulsions, and issues with mobility or senses including sight and hearing.
Encephalitis can be life-threatening in some situations. Because it's impossible to anticipate how encephalitis may impact each person, prompt diagnosis and treatment are critical.
Symptoms
The majority of patients who have viral encephalitis experience flu-like symptoms, such as:
- Headache
- Fever
- Aches in muscles or joints
- Fatigue or weakness
The signs and symptoms might be more severe at times, and may include:
- Confusion, agitation or hallucinations
- Seizures
- Loss of sensation or paralysis in certain areas of the face or body
- Muscle weakness
- Problems with speech or hearing
- Loss of consciousness (including coma)
Signs and symptoms in newborns and young children may 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 should you see a doctor?
If you're suffering any of the more severe symptoms of encephalitis, get medical help right once. A strong headache, a fever, and a change in consciousness necessitate immediate medical attention. Any indications or symptoms of encephalitis in infants and young children should be treated immediately.
Causes
In many cases, the actual etiology of encephalitis is unclear. However, when a cause is identified, a viral infection is the most prevalent. Encephalitis can be caused by bacterial infections as well as non-infectious inflammatory disorders.
There are two forms of encephalitis: acute and chronic.
- Primary encephalitis: When a virus or other agent penetrates the brain directly, this situation results. It's possible that the illness is localized or widespread. A primary infection might be the reactivation of a virus that was dormant during a prior sickness.
- Secondary encephalitis: A defective immune system response to an infection elsewhere in the body causes this illness. Instead of fighting solely the infection-causing cells, the immune system erroneously destroys healthy brain cells. Secondary encephalitis, also known as post-infection encephalitis, develops two to three weeks following the first illness.
Common Causes
The viruses that can cause encephalitis include:
- Herpes simplex virus (HSV): HSV type 1 (which causes cold sores and fever blisters around the mouth) and HSV type 2 (which causes genital herpes) can both cause encephalitis. HSV type 1 encephalitis is uncommon, although it can cause serious brain damage or death.
- Other herpes viruses: The Epstein-Barr virus, which causes infectious mononucleosis, and the varicella-zoster virus, which causes chickenpox and shingles, are two examples.
- Enteroviruses: The poliovirus and the coxsackievirus, for example, are viruses that induce flu-like symptoms, eye irritation, and stomach pain.
- Mosquito-borne viruses: Infections such as West Nile, La Crosse, St. Louis, western equine, and eastern equine encephalitis can be caused by these viruses. After being exposed to a mosquito-borne virus, symptoms of illness may occur from a few days to a few weeks.
- Tick-borne viruses: Ticks carry the Powassan virus, which causes encephalitis in people in the Midwest. Symptoms often occur a week after being bitten by an infected insect.
- Rabies virus: Once infected with the rabies virus, which is generally transmitted by a bite from an infected animal, symptoms progress quickly to encephalitis. In the United States, rabies is an uncommon cause of encephalitis.
- Childhood infections: Secondary encephalitis used to be caused by common childhood diseases including measles (rubeola), mumps, and German measles (rubella). Due to the availability of vaccines for these illnesses, these causes are now uncommon in the United States.
Risk Factors
Encephalitis may strike anyone at any time. The following are some of the factors that may raise your risk:
- Age: In some age groups, some kinds of encephalitis are more prevalent or more severe. Most kinds of viral encephalitis put young children and elderly individuals at a higher risk.
- Weakened immune system: Encephalitis is more likely among those who have HIV/AIDS, take immune-suppressing medicines, or have another illness that weakens the immune system.
- Geographical regions: Viruses spread by mosquitos or ticks are frequent in certain geographical areas.
- Season of the year: In many parts of the United States, mosquito- and tick-borne illnesses are more prevalent in the summer.
Complications
The severity of encephalitis consequences varies, based on variables such as:
- Your age
- The cause of your infection
- The severity of your initial illness
- The time from disease onset to treatment
People who have a minor sickness normally recover in a few weeks with no long-term consequences.
Severe disease complications
Inflammation can cause brain damage, which might lead to a coma or death. Other consequences, which might range in severity, can last for months or even be permanent. The following are examples of complications:
- Persistent fatigue
- Weakness or lack of muscle coordination
- Personality changes
- Memory problems
- Paralysis
- Hearing or vision defects
- Speech impairments
Prevention
The best method to avoid getting viral encephalitis is to avoid being exposed to viruses that might cause it. Make an effort to:
- Maintain a healthy level of hygiene.
- Hands should be washed with soap and water regularly and thoroughly, especially after using the restroom and before and after meals.
- Utensils should not be shared.
- Tableware and beverages should not be shared.
- Instill positive behaviors in your children. Make sure kids maintain proper hygiene at home and at school, and that they do not share utensils.
- Vaccinate yourself.
- Ensure that your own and your children's vaccines are up to date.
- Before you go, talk to your doctor about the vaccines that are suggested for particular places.
Anti-mosquito and anti-tick protection
To keep mosquitoes and ticks at bay, use the following precautions:
- Protect yourself by dressing appropriately: If you're outside between dark and dawn, when mosquitoes are most active, and if you're in a forested region with tall grasses and bushes, when ticks are more abundant, wear long-sleeved shirts and long pants.
- Mosquito repellant should be used: DEET, for example, may be applied to both the skin and the clothing. Spray the repellant on your hands and then rub it over your face to apply it. Apply sunscreen first if you're wearing both sunscreen and a repellent.
- Insecticide should be used: Permethrin-based treatments, which repel and kill ticks and mosquitoes, are recommended by the Environmental Protection Agency. Clothing, tents, and other outdoor gear can be sprayed using these chemicals. The skin should not be exposed to permethrin. Mosquitoes should be avoided. Avoid needless activity in areas where mosquitoes are prevalent. If at all possible, stay indoors between dark and dawn, when mosquitoes are most active. Replace any broken screens or windows.
- Remove all water sources from your property: Remove any standing water in your yard that mosquitos can use to lay their eggs. Flowerpots or other gardening containers, flat roofs, old tires, and clogged gutters are all common issues.
- Look for indications of viral sickness outside: If you see sick or dying birds or animals, contact your local health department to report your findings.
Young children's protection
Insect repellents are not suggested for infants under the age of two months. Instead, use mosquito netting to cover an infant carrier or stroller. Repellents with 10% to 30% DEET are deemed safe for older babies and toddlers. Children should avoid products that include both DEET and sunscreen since reapplication — which may be necessary for the sunscreen component — will expose the kid to too much DEET.
The following are some suggestions for applying mosquito repellent with children:
- 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.