Health Library

Bacterial Meningitis

Definition

The brain and spinal cord are covered by layers of tissue. These layers are called the meninges. Bacterial meningitis is an infection of the meninges and cerebrospinal fluid (CSF), a clear fluid that surrounds and protects the brain and spinal cord.

Bacterial meningitis a serious infection. It is a medical emergency, requiring immediate treatment. Depending on the severity of the infection, it can result in death within hours.

Bacterial Meningitis
Meningitis
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Causes

Bacterial meningitis can be caused by many different specific bacteria. The likelihood of having one type of bacteria over another varies by age group. Severity of the infection depends on the bacteria causing it and your the overall health of your immune system.

Transmission of the bacteria usually occurs by direct contact with oral or respiratory secretions, such as inhaling droplets from someone who sneezes or coughs, or by kissing. The spread of the bacteria depends on the time of the year, crowding, and the presence other respiratory infections.

Risk Factors

Bacterial meningitis is more common in infancy and childhood. For adults, the risk increases as you age. Other factors that may increase your chance of getting bacterial meningitis include:

  • Not having recommended vaccinations
  • Community living arrangements, such as a college dormitory or military base
  • People in close and prolonged contact with people with meningitis
  • Supressed immune system caused by certain health conditions or medications
  • Penetrating head trauma
  • Previous brain surgery, or cerebrospinal fluid shunts
  • Birth defects, such as dermal sinus or myelomeningocele, a type of spina bifida
  • A history of epidural steroid injections or other invasive spinal procedures
  • Cochlear implants
  • Alcoholism
  • Smoking, or exposure to second-hand smoke

Symptoms

Classic symptoms can develop over several hours or may take one to two days:

  • High fever
  • Headache
  • Very stiff, sore neck

Other symptoms may include:

  • Red or purple skin rash
  • Bluish skin color
  • Nausea
  • Vomiting
  • Sensitivity to bright lights
  • Sleepiness
  • Mental confusion
  • Seizures

In newborns and infants, symptoms are hard to see. As a result, infants under three months old with a fever are often checked for meningitis. Symptoms in newborns and infants may include:

  • Inactivity
  • Unexplained high fever or any form of temperature instability, including a low body temperature
  • Irritability
  • Vomiting
  • Yellowing of the skin or eyes—jaundice
  • Feeding poorly or refusing to eat
  • Tightness or bulging of soft spots between skull bones
  • Difficulty awakening

Complications of bacterial meningitis include:

  • Systemic infection—sepsis
  • Shock (very low blood pressure)
  • Seizures
  • Brain swelling
  • Fluid build up in the brain—hydrocephalus
  • Hearing loss
  • Vision problems
  • Paralysis
  • Coma
  • Death

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done.

Tests may include the following:

  • Blood tests
  • Lumbar puncture—to evaluate CSF
  • Cultures of blood, urine, mucous, and/or pus from skin

Imaging tests of the brain and spinal cord may be done with an MRI scan or CT scan.

Treatment

More than 90% of all people with this infection survive with immediate care, including:

  • Antibiotics and corticosteroids—often given together
  • Fluids

Antibiotics

Antibiotics are given through an IV. This is started as soon as the infection is suspected. The antibiotics may be changed once tests find the exact bacterial cause. People usually stay in the hospital until the fever has fallen and the fluid around the spine and the brain is clear of infection. This may require a hospital stay of several days.

Corticosteroids

These are usually given by IV early in treatment, but are generally used for specific causes of meningitis. Corticosteroids control brain pressure and swelling. They also reduce the body’s production of inflammatory substances. This treatment can prevent further damage. Specifically, it reduces the risk of hearing loss and neurological complications.

Fluid Replacement

Fluids can be lost due to fever, sweating, or vomiting. They may be replaced through an IV. It will be done carefully to avoid complications of fluid overloading.

Other Medications

Your doctor may also recommend:

  • Pain relievers
  • Sedatives
  • Anticonvulsants
  • Medications to help reduce brain swelling
  • Glycerol to reduce the risk of hearing loss and neurological complications

Prevention

To help reduce your chance of getting bacterial meningitis:

  • If you have been exposed to meningitis, or are a carrier or healthcare worker, you may need to take prophylactic antibiotics to prevent infection.
  • Find out the status of you and your families vaccinations.
  • Buy pasteurized milk and milk products.
  • Talk to your doctor if you are pregnant so you can be monitored.

Resources

Centers for Disease Control and Prevention
http://www.cdc.gov

Meningitis Foundation of American
http://www.meningitisfoundationofamerica.org

Canadian Resources

Health Canada
http://www.hc-sc.gc.ca

Meningitis Research Foundation of Canada
http://www.meningitis.ca

References

Bacterial meningitis in adults. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 16, 2013. Accessed May 30, 2014.

Bacterial meningitis in infants and children. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated May 14, 2014. Accessed May 30, 2014.

Bamberger D. Diagnosis, initial management, and prevention of meningitis. Am Fam Physician. 2010;82(12):1491-1498.

Lumbar puncture. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated May 31, 2012. Accessed May 30, 2014.

Meningitis and encephalitis fact sheet. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/encephalitis%5Fmeningitis/detail%5Fencephalitis%5Fmeningitis.htm. Updated April 16, 2014. Accessed May 30, 2014.

Meningococcal disease. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/meningococcal/about/index.html. Updated April 1, 2014. Accessed May 30, 2014.

Meningococcal vaccine. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated January 12, 2014. Accessed May 30, 2014.

Weisfelt M, de Gans J, et al. Community-acquired bacterial meningitis in alcoholic patients. PLoS One. 2010;5(2):e9102.

10/2/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Centers for Disease Control and Prevention. Updated recommendation from the Advisory Committee on Immunization Practices (ACIP) for revaccination of persons at prolonged increased risk for meningococcal disease. MMWR. 2009;58(37):1042-1043.

4/22/2011 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Lee CC, Middaugh NA, Howie SR, Ezzati M. Association of secondhand smoke exposure with pediatric invasive bacterial disease and bacterial carriage: a systematic review and meta-analysis. PLoS Med. 2010;7(12).

1/2/2014 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Zalmanovici T, Fraser A, et al. Antibiotics for preventing meningococcal infections. Cochrane Database Syst Rev. 2013;10:CD004785.