Which part of body is affected by encephalitis?

The brain.

Encephalitis is a general term for inflammation of the brain. It can be caused by a variety of factors, including viruses, bacteria, fungi, and parasites. Encephalitis can range in severity from mild to life-threatening. Symptoms of encephalitis can include fever, headache, confusion, seizures, and difficulty speaking or understanding speech. Treatment for encephalitis depends on the cause of the inflammation and may include antiviral medications, antibiotics, or corticosteroids.