Meningitis refers to inflammation of the meninges, or the layers protecting the brain and spinal cord. It can be caused by medication or infection from bacteria, viruses or fungi. Meningitis becomes life threatening when inflammation damages the brain and spinal cord. Effects of this inflammation can result in brain damage, stroke, seizure and sometimes death. Meningitis can be either septic or aseptic. Septic, or bacterial, meningitis is potentially fatal and occurs when bacteria invade the meninges through the bloodstream, leading to brain damage. Aseptic meningitis is rare and generally should not be cause for concern. Flu-like symptoms of aseptic meningitis include fever, headaches, vomiting, lethargy and a stiff neck.
Viruses
Enteroviruses, which are often found in the digestive tract, are the most common causes for aseptic meningitis. They account for about half of all cases, according to Medline Plus, and are spread by fecal contamination due to poor hygiene. The West Nile Virus is another viral strain that can cause aseptic meningitis; it is spread through the bite of an infected mosquito. Doctors, nurses and other hospital personnel are at highest risk of viral exposure. HIV or AIDS patients, children in a day care setting and those who have the flu are also at increased risk of the disease. Once meningitis is suspected, a doctor does a procedure called a spinal tap and extracts spinal fluid through a needle inserted into the spine. Viral cultures, antibody measurements and a PCR (polymerase chain reaction) DNA test are also conducted. Viral infections usually clear up within one to two weeks and don't require medication, although certain viruses are treated with antiviral drugs.
Bacteria
Rare forms of bacteria such as Mycobacteria (the cause of tuberculosis) and Lyme disease cause aseptic meningitis. Mycobacteria spreads through the cough of an infected tuberculosis patient; Lyme disease spreads through tick bites. Treatment for this type of aseptic meningitis involves antibiotic drug therapy.
Fungi
The complex organisms known as fungi behave similarly to bacteria and may be found throughout nature. Fungi are able to infect the air, food and water. The elderly and those with weakened immune systems, such as HIV or AIDS patients, are at high risk of developing aseptic meningitis from fungal sources. Fungal cultures of spinal fluid help diagnose the disease. Treatment involves antifungal drug therapy.
Chemicals/Medications
Chemicals such as dyes that are injected into the brain for diagnostic purposes may cause inflammation. Antibiotics and anti-inflammatory medications can also cause inflammation in some people. Treatment involves stopping or adjusting the dosage of the chemical or medication as needed.
