|Bacterial Meningitis |
Bacterial meningitis is an infection and inflammation of the meninges. The meninges are the membranes that surround the brain and spinal cord. Bacterial meningitis can cause death within hours, so quick diagnosis and treatment is vital.
Worldwide, three types of bacteria cause the majority of cases of acute bacterial meningitis:
- Streptococcus pneumoniae (the bacteria that causes pneumonia)
- Neisseria meningitidis
- Haemophilus influenzae b (Hib)
Other forms of bacterial meningitis include Listeria monocytogenes meningitis, Escherichia coli meningitis, and Mycobacterium tuberculosis meningitis.
These bacteria first cause an upper respiratory tract infection, and then travel through the blood stream to the brain.
In the United States, widespread immunization has almost eliminated meningitis due to Hib. A variety of other bacteria can also cause meningitis, particularly in newborn babies and the elderly.
Some forms of bacterial meningitis are spread by direct contact with discharge from the mouth or throat of an infected person (e.g., kissing). In general, meningitis is not spread by casual contact.
The following factors increase your chances of developing bacterial meningitis. If you have any of these risk factors, tell your doctor:
- Age: infancy and early childhood; over 60 years of age
- People in close and prolonged contact with patients with meningitis due to Hib or Neisseria meningitidis
- A weakened immune system due to HIV infection or other conditions
- Smoking (for meningitis due to Neisseria meningitidis)
- Living in proximity to others, such as dormitories and military barracks (for meningitis due to Neisseria meningitidis)
Classic symptoms can develop over several hours, or may take 1-2 days:
- High fever
- Very stiff, sore neck
Other symptoms may include:
- Red or purple skin rash
- Cyanosis (bluish skin color)
- Photophobia (sensitivity to bright lights)
- Mental confusion
In newborns and infants, classic symptoms are difficult to detect. Because symptoms in newborns and infants are unreliable, infants under three months old with a fever are often evaluated for meningitis. Symptoms in newborns and infants may include:
- Unexplained high fever or any form of temperature instability, including a low body temperature
- Jaundice (yellow color to the skin)
- Feeding poorly or refusing to eat
- Tautness or bulging of soft spots between skull bones
- Difficulty awakening
As bacterial meningitis progresses, patients of all ages may experience seizures and/or hearing loss.
Your doctor will ask about your symptoms and medical history, and perform a physical exam.
Tests may include the following:
- Spinal tap – removal of a small amount of cerebrospinal fluid to check for bacteria
- Other cultures – testing of samples of blood, urine, mucous, and/or pus from skin infections
- MRI scan – a test that uses magnetic waves to make pictures of structures inside the body (to be sure the inflammation is not from some other cause, such as a tumor)
- CT scan – a type of x-ray that uses a computer to make pictures of structures inside the body
When treatment is provided immediately, more than 90% of all people with bacterial meningitis survive. Antibiotics and many times corticosteroids are given together to treat bacterial meningitis. Fluid replacement may also be given. Talk with your doctor about the best treatment plan for you. Treatment options include:
Antibiotics given through an intravenous line are administered as soon as bacterial meningitis is suspected. The antibiotics may be changed once tests identify the exact bacterial cause of meningitis. Patients usually stay in the hospital until fever has subsided and the cerebrospinal fluid is clear of infection.
Intravenous corticosteroids are usually given early in the course of treatment, to control brain pressure and swelling, and reduce the body’s production of inflammatory substances that can cause further damage.
Fluids lost due to fever, sweating, or vomiting are cautiously replaced to avoid complications of fluid overloading.
Pain medications and sedatives may be used to reduce pain and fever. In addition, anticonvulsants may be prescribed to prevent seizures.
To help reduce your chances of getting bacterial meningitis, take the following steps:
- Vaccines against Hib, which are very safe and highly effective, given to young children
- Meningococcal conjugate vaccine (MCV4) against certain strains of Neisseria meningitidis, given to:
- All children at their routine preadolescent visit (11-12 years of age), and again at high school entry
- Other adolescents who want to decrease their risk of meningitis
- College freshmen living in dormitories
- Microbiologists who are routinely exposed to meningococcal bacteria
- US military recruits
- People with a damaged or removed spleen
- People with terminal complement component deficiency (an immune system disorder)
- People traveling to countries which have an outbreak of meningitis
- People who might have been exposed to meningitis during an outbreak
- Meningococcal polysaccharide vaccine (MPSV4; used if MCV4 is not available) against certain strains of Neisseria meningitidis, given to:
- At-risk children 2-10 years old
- At-risk adults over 55
- Pneumococcal polysaccharide vaccine against Streptococcus pneumoniae, given to:
- All people over age 65
- People ages 2-64 with certain chronic medical problems
- Pneumococcal conjugate vaccine against Streptococcus pneumoniae, given to:
- All children older than 2
- Preventative antibiotics given to health care workers or family members in close contact with infected patients
- Pasteurization of milk and milk products to prevent meningitis due to Listeria monocytogenes
- Monitoring for maternal infection during and before labor to prevent meningitis in newborns