Meningitis is swelling and irritation (inflammation) of the membranes covering the brain and spinal cord. This inflammation causes changes in the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord.
The most common causes of meningitis are viral infections that usually get better without treatment. However, bacterial meningitis infections are extremely serious, and may result in death or brain damage even if treated.
Acute bacterial meningitis is a true medical emergency, and requires immediate treatment in a hospital.
Viral meningitis is milder and occurs more often than bacterial meningitis. It usually develops in the late summer and early fall, and often affects children and adults under age 30. Most infections occur in children under the age of 5. Most viral meningitis is due to enteroviruses, which are viruses that also cause intestinal illness.
Many other types of viruses can cause meningitis. For example, viral meningitis can be caused by herpes viruses, the same virus that can cause cold sores and genital herpes (although people with cold sores or genital herpes are not at a greater risk of developing herpes meningitis).
Recently, West Nile virus, spread by mosquito bites, has become a cause of viral meningitis in most of the United States.
Symptoms
Fever and chills
Mental status changes
Nausea and vomiting
Sensitivity to light (photophobia)
Severe headache
Stiff neck (meningismus)
Other symptoms that can occur with this disease:
Agitation
Bulging fontanelles
Decreased consciousness
Opisthotonos
Poor feeding or irritability in children
Rapid breathing
Meningitis is an important cause of fever in newborn children.
Meningitis - H. influenzae (2 images)(Doctor-Reviewed information)
Haemophilus influenzae meningitis is a bacterial infection of the membranes covering the brain and spinal cord (meninges. See also: Aseptic meningitis; Meningitis; Meningitis - cryptococcal; Meningitis - gram-negative; Meningitis - meningococcal; Meningitis - pneumococcal; Meningitis - staphylococcal; Meningitis - tuberculous. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Jatin M. Vyas, PhD, MD, Instructor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/28/2008
Meningitis - cryptococcal (1 image)(Doctor-Reviewed information)
Cryptococcal meningitis is a fungal infection of the membranes covering the brain and spinal cord (meninges. See also: Aseptic meningitis; Meningitis - gram-negative; Meningitis - H. influenzae; Meningitis - meningococcal; Meningitis - pneumococcal; Meningitis - staphylococcal; Meningitis - tuberculous. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Jatin M. Vyas, PhD, MD, Instructor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/28/2008
Meningitis - meningococcal (1 image)(Doctor-Reviewed information)
Meningococcal meningitis is an infection that causes swelling and irritation (inflammation) of the membranes covering the brain and spinal cord. See also: Aseptic meningitis; Meningitis; Meningitis - cryptococcal; Meningitis - gram-negative; Meningitis - H. influenzae; Meningitis - pneumococcal; Meningitis - staphylococcal; Meningitis - tuberculous. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Jatin M. Vyas, PhD, MD, Instructor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/28/2008
Meningitis - pneumococcal (2 images)(Doctor-Reviewed information)
Pneumococcal meningitis is a bacterial inflammation or infection of the membranes covering the brain and spinal cord. See also: Aseptic meningitis; Meningitis; Meningitis - cryptococcal; Meningitis - gram-negative; Meningitis - H. influenzae; Meningitis - meningococcal; Meningitis - staphylococcal; Meningitis - tuberculous. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Jatin M. Vyas, PhD, MD, Instructor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/28/2008
Meningitis - staphylococcal (1 image)(Doctor-Reviewed information)
Staphylococcal meningitis is a bacterial infection of the membranes covering the brain and spinal cord (meninges. See also: Aseptic meningitis; Meningitis - cryptococcal; Meningitis - gram-negative; Meningitis - H. influenzae; Meningitis - meningococcal; Meningitis - pneumococcal; Meningitis - tuberculous. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, PhD, MD, Instructor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/28/2008
Aseptic meningitis (1 image)(Doctor-Reviewed information)
Aseptic meningitis is an illness that appears similar to bacterial meningitis; however, bacteria do not grow in cultures of the fluid around the brain and spinal cord (cerebrospinal fluid. See also: Meningitis; Meningitis - cryptococcal; Meningitis - gram-negative; Meningitis - H. influenzae; Meningitis - meningococcal; Meningitis - pneumococcal; Meningitis - staphylococcal; Meningitis - tuberculous. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Jatin M. Vyas, MD, PhD, Instructor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/28/2008
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