What causes meningitis and encephalitis?
Meningitis and encephalitis are usually caused by viruses or bacteria. Most often, the body’s immune system is able to contain and defeat an infection. But if the infection passes into the blood stream and then into the cerebrospinal fluid that surrounds the brain and spinal cord, it can affect the nerves and travel to the brain and/or surrounding membranes, causing inflammation. This swelling can harm or destroy nerve cells and cause bleeding in the brain. Meningitis Meningitis is most often caused by a bacterial or viral infection. It also may be caused by a fungal infection, a reaction to certain medications or medical treatments, an inflammatory disease such as lupus, some types of cancer, or a traumatic injury to the head or spine. Bacterial meningitis is a rare but potentially fatal disease. It can be caused by several types of bacteria that first cause an upper respiratory tract infection and then travel through the blood stream to the brain. The disease can also occur when cert
