Encephalitis is an acute inflammation of the human brain. The causes of encephalitis are typically viral infections but on occasion can be bacterial infections. If the brain is infected first, it is primary encephalitis, whereas secondary encephalitis is the result of another portion of the body being attacked before the infection spreads to the brain. These are the two basic types of encephalitis.
The herpes virus can lead to encephalitis, whether it is herpes simplex virus one (HSV1) or herpes simplex virus two (HSV2). Fatal sporadic encephalitis comes from HSV1 but is rare. Throat and chest viruses such, as the flu, and gut viruses, such as Echo virus, also can be causes of encephalitis.
Varicella-zoster virus, which is responsible for chicken pox and shingles, can lead to encephalitis. Epstein-Barr virus happens when a herpes virus causes infectious mononucleosis, also called mono, that ultimately leads to an attack on the brain. Preventable childhood viruses such as measles, mumps or rubella can be causes of encephalitis as well.
Rabies, which is transmitted by the bite or scratch from an infected animal, is another one of the viral causes of encephalitis. Arboviruses are carried by mosquitoes and ticks. Most mosquito-borne diseases can be causes of encephalitis. Tick-borne encephalitis can come from lyme disease and other bacterial infections. The most notable forms of mosquito-borne diseases that are causes of encephalitis include West Nile encephalitis, Western equine encephalitis, Eastern equine encephalitis, St. Louis encephalitis and La Crosse encephalitis.
Many bacterial infections can result in encephalitis as well. Some of the major types include lyme disease, mycoplasma and listeria. Pneumococcal and meningococcal infections can cause encephalitis as well.
The spread of encephalitis is not caused only by the spread of bacteria and viruses. Fungi can be causes of encephalitis — as a result of histoplasma, cryptococcus or candida, for example. Parasites are another way that encephalitis is spread. Malaria and toxoplasma are two prime examples of parasites that can carry encephalitis. It can even happen as a result of a reaction to drugs.
Yet another way that encephalitis can occur is post-infectious encephalitis or autoimmune encephalitis. This is what happens when the immune system mistakenly attacks the brain while trying to fight off an infection in another part of the body. Avoiding encephalitis requires diligence, because it has many causes. One should avoid rabid animals and herpes carriers and should be aware of insect and tick bites, parasites and exposure to bacterias, viruses and some fungi.
