When a person has meningitis, she has an inflammation of the meninges, which are the membranes that cover the spinal cord and brain. Patients with meningitis can have symptoms such as fever and chills, a stiff neck, severe headache, sensitivity to light, and nausea and vomiting. A virus or bacterium usually causes meningitis, though the National Institute of Neurological Disorders and Stroke noted that meningitis may be caused by a traumatic injury, fungal infection (such as Crytococcus neoformans causing crytococcal meningitis), certain types of cancer, reaction to a treatment, or an inflammatory disease. Knowing the type of meningitis a person has is important: finding the appropriate antibiotic can prevent spreading of a type of bacterial meningitis, according to the National Center for Immunization and Respiratory Diseases.
Bacterial Meningitis
Several different types of bacteria can cause meningitis. The National Institute of Neurological Disorders and Stroke reported that 6,000 cases of pneumococcal meningitis in the United States each year. This type of bacterial meningitis is caused by Streptococcus pneumonaie. Pneumococcal meningitis can cause long-term neurological complications, such as seizures and brain damage, in 25 to 50 percent of patients and 20 percent of patients die, according to MedlinePlus.
One type of bacterial meningitis that college-bound students may have heard of is meningococcal meningitis, caused by the bacterium Neisseria meningitidis. About 2,600 people in the United States each year get this type of bacterial meningitis, according to the National Institute of Neurological Disorders and Stroke. This type of bacterial meningitis is spread from person to person, such as through living in close quarters or have close contact with someone with the infection.
A rare form of bacterial meningitis is tuberculous meningitis, caused by the bacterium Mycobacterium tuberculosis; this is the same bacterium that causes the disease tuberculosis. MedlinePlus noted that people who are at higher risk for this type of bacterial meningitis include those with AIDS, pulmonary tuberculosis, a weakened immune system or people who use alcohol excessively.
Several other bacteria can cause meningitis. These include the Staphylococcus bacteria, such as Staphylococcus epidermidis or Staphylococcus aureus, that cause staphylococcal meningitis; and the bacterium Haemophilus influenzae, which causes H. influenzae meningitis. Patients may have gram-negative meningitis, in which the meningitis is caused by gram-negative bacteria—bacteria that become pink when a stain is introduced. MedlinePlus listed Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter aerogenese and Escherichia coli.
Viral Meningitis
Also called aseptic meningitis, viral meningitis is the most common type of meningitis, according to the National Institute of Neurological Disorders and Stroke. Viruses that can cause meningitis include enteroviruses, herpes simplex type 2, varicella zoster, HIV, mumps and influenza. This type of meningitis tends to be mild.
References
National Institute of Neurological Disorders and Stroke. Meningitis and Encephalitis Fact Sheet. 2011. Web. 20 April 2011
http://www.ninds.nih.gov/disorders/encephalitis_meningitis/detail_encephalitis_meningitis.htm
A.D.A.M. Meningitis – Crytococcal. MedlinePlus, 2011. Web. 20 April 2011
http://www.nlm.nih.gov/medlineplus/ency/article/000642.htm
National Center for Immunization and Respiratory Disease. Meningitis: Questions and Answers. Centers for Disease Control and Prevention, 2011. Web. 20 April 2011
http://www.cdc.gov/meningitis/about/faq.html
A.D.A.M. Meningitis – Pneumococcal. MedlinePlus, 2011. Web. 20 April 2011
http://www.nlm.nih.gov/medlineplus/ency/article/000607.htm
WHO Media Centre. Meningococcal Meningitis. World Health Organization, 2010. Web. 20 April 2011
http://www.who.int/mediacentre/factsheets/fs141/en/
A.D.A.M. Meningitis – Tuberculous. MedlinePlus, 2011. Web. 20 April 2011
http://www.nlm.nih.gov/medlineplus/ency/article/000650.htm
A.D.A.M. Meningitis – Staphylococcal. MedlinePlus, 2011. Web. 20 April 2011
http://www.nlm.nih.gov/medlineplus/ency/article/000613.htm
A.D.A.M. Meningitis – H. Influenzae. MedlinePlus, 2011. Web. 20 April 2011
http://www.nlm.nih.gov/medlineplus/ency/article/000612.htm
A.D.A.M. Meningitis – Gram-negative. MedlinePlus, 2011. Web. 20 April 2011
http://www.nlm.nih.gov/medlineplus/ency/article/000610.htm