Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Encephalitis ?
    ### Response:
    Encephalitis is an inflammation of the brain. Usually the cause is a viral infection, but bacteria can also cause it. It can be mild or severe. Most cases are mild. You may have flu-like symptoms. With a mild case, you may just need rest, plenty of fluids, and a pain reliever.
    