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 is 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

Copyright © Nucleus Medical Media, Inc.

Causes

Bacterial meningitis can be caused by many different 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 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
• Alcohol use disorder
• Smoking, or exposure to second-hand smoke

Symptoms

Classic symptoms can develop over several hours or may take 1-2 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 notice. As a result, infants under 3 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
• 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

You will be asked about your symptoms and medical history. A physical exam will be done.

Your bodily fluids may be tested. This can be done with:

• Blood tests and cultures
• Urine tests
• Tests of mucous and pus from your skin
• Lumbar puncture

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 advise:

• 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.
• Make sure your vaccinations are up to date. Check on the vaccination status of your family members as well.
• Buy pasteurized milk and milk products.
• Talk to your doctor if you are pregnant so you can be monitored.