Causes of encephalitis
Encephalitis is a condition characterized by inflammation of the brain. The causes of encephalitis can vary, but they generally fall into two categories: infectious and non-infectious causes.
Infectious causes of encephalitis include:
1. Viral infections: Viruses are the most common cause of encephalitis. Examples include herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and enteroviruses.
2. Bacterial infections: Certain bacteria can cause encephalitis, although it is less common. Examples include Mycoplasma pneumoniae, Borrelia burgdorferi (causing Lyme disease), and rickettsial infections.
3. Parasitic infections: In rare cases, parasites like Toxoplasma gondii, Naegleria fowleri, or Trypanosoma brucei can cause encephalitis.
Non-infectious causes of encephalitis include:
1. Autoimmune disorders: Conditions such as autoimmune encephalitis, systemic lupus erythematosus (SLE), or vasculitis can trigger an immune response leading to inflammation of the brain.
2. Vaccines: Extremely rare cases of encephalitis have been associated with certain vaccines, such as the measles, mumps, and rubella (MMR) vaccine.
3. Toxic substances: Exposure to certain toxins, chemicals, or heavy metals can lead to encephalitis. Examples include lead, mercury, and carbon monoxide poisoning.
4. Drug reactions: Some medications can cause an immune response that leads to encephalitis. These include certain antibiotics, anticonvulsants, and non-steroidal anti-inflammatory drugs (NSAIDs).
It is important to note that encephalitis can develop due to a combination of factors and that the specific cause may not always be identified.