Causes of Meningitis

Meningitis is generally caused by a viral infection in which case the treatment is usually home-care, rest and recuperation. Obtaining an accurate diagnosis is paramount to ensure correct treatment of the disease however, and patients should not risk self-diagnosis with this potentially life-threatening condition. Any rapid progression of symptoms, even if a diagnosis of viral meningitis has already been given, should be brought to the attention of a medical professional immediately for further investigation. Other causes of meningitis include bacterial infection, trauma, fungal infection, and even neck surgery.

Bacterial Meningitis

Bacterial meningitis is usually caused by the Stereptococcus pneumoniae bacteria but the Neisseria meningitidis bacteria is the one that is connected to outbreaks where crowded conditions occur, such as in college dormitories or army barracks. Another bacteria, Haemophilus influenzae type B (Hib) is also responsible for some cases of meningitis in children and adults but has become less of an issue since children began receiving the Hib vaccine as standard in infancy.

The bacteria that cause meningitis may already live in the body, specifically in the nose and mouth, but it is when they enter the general circulation and reach the meninges of the brain that the problems begin. The brain is usually protected from the body’s immune system, and therefore an autoimmune attack, by the meninges which create a barrier; often referred to as the blood/brain barrier. Unfortunately the bacteria involved in meningitis may occasionally cross this barrier and are then able to attack the brain and central nervous system with little or no initial resistance, spreading rapidly and causing widespread tissue damage, inflammation, and irritation. The problem may actually be exacerbated as the immune system does eventually mount an attack as the blood vessels near the brain can become more permeable than they should be leading to infiltration of white blood cells, fluid and other immune system cells into the central nervous system. This can cause increased swelling of the brain, with resulting decreased blood flow (ischaemia) to some brain cells and more brain damage.

Other Causes of Meningitis

Occasionally meningitis is a result of trauma to the brain, head, or neck, and may occur due to some surgical procedures, such as neck pain surgery. Ear and sinus infections are also potential causes of meningitis. Epidemiological studies show that African Americans contract meningitis at a disproportionally high rate compared to those of other ethnicities. Men and women are affected equally, and the average age for meningitis is 25yrs old. Others who are at high risk include the elderly, children under the age of five, alcoholics, cancer patients (chemotherapy increases the risk of meningitis), those with sickle cell anaemia, diabetics, and recent transplant patients taking immunosuppressive drugs. Further risk factors include living in cramped conditions, such as a college environment, military barracks, or inadequate housing, IV drug use, and the presence of hydrocephalus shunts.

Next read about: Symptoms of Meningitis

Last Updated: 10/10/2010