Encephalitis is a serious medical condition that causes  inflammation of the brain. It is most commonly caused by viral infections and occurs more often in the first year of life and decreases with age. Depending on the severity of an individual’s condition, encephalitis can cause symptoms ranging from fever, headache, and muscle tenderness to confusion, seizures and paralysis. Since encephalitis is an unpredictable condition, it is important to get a proper diagnosis and seek medical attention as soon as possible.



Most individuals with viral encephalitis have either no symptoms or flu-like symptoms, such as:

  • Mild headache
  • Temperature
  • Muscle tenderness
  • Tiredness


In more severe cases of encephalitis, signs and symptoms may include:

  • Muscle weakness
  • Loss of consciousness
  • Blurred or double vision
  • Paralysis
  • Seizures
  • Confusion or hallucinations
  • Speech impairment
  • Hearing impairment
  • Perception to foul smells


Signs and symptoms in infants and young children may also include:

  • Bulging in the soft spots of the skull in infants
  • Sickness/vomiting
  • Muscle tenderness
  • Feeling distraught/persistent crying/irritability
  • Loss of appetite



Encephalitis is most often caused by a viral infection. Exposure to viruses can occur through:

  • Breathing in respiratory droplets from an infected individual
  • Drinking or eating from contaminated food or water
  • Getting mosquito or bug bites
  • Skin contact

Other causes of encephalitis may include the following:

  • Allergic reaction to vaccinations
  • Autoimmune disease
  • Bacteria
  • Parasites
  • Effects of conditions such as cancer


Risk factors 

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

  • Age: more common in young children and older adults
  • Weak immune system: having certain illnesses such as  HIV or AIDS
  • Geographic locations: more common in regions that are prone to viruses
  • Time of the year: more common in spring, summer and early fall



Possible complications that might arise from severe encephalitis include the following:

  • Extreme tiredness
  • Weakened muscle movement
  • Changes in personality and behavior
  • Memory loss
  • Hearing impairment
  • Speech impairment
  • Paralysis
  • Epilepsy




A few recommendations for preventing risk of developing encephalitis include:

  • Practicing good hygiene
  • Getting vaccinations (for measles, mumps and rubella)
  • Properly washing and avoiding sharing utensils
  • Dressing in protective outdoor gear
  • Wearing mosquito repellent when necessary
  • Using EPA-recommended insecticide