What Is Bacterial Meningitis?
Meningitis describes inflammation of the meninges, the layers of membranes that surround the brain and spinal cord. Viruses, fungi, bacteria, and other rare causes can lead to meningitis. Streptococcus, Neisseria, Listeria, and Haemophilus are common bacterial causes of meningitis.
Symptoms escalate quickly and may include a headache, fever, stiff neck, nausea and vomiting, confusion, and sensitivity to light. Bacterial meningitis can lead to sepsis and permanent brain damage and is a life-threatening medical emergency. If it is suspected, take the patient to the emergency room or call 911.
Antibiotics are the predominant treatment for bacterial meningitis. Vaccines can also help protect against bacterial meningitis.
You should seek care urgently at the nearest Emergency Room. Tests need to be run as soon as possible in order to determine the cause of the infection, and treat as soon as possible to avoid lasting complications. Early diagnosis and treatment with antibiotics is vital for the treatment of meningitis.
How common is bacterial meningitis?
Bacterial meningitis is also known as
- Acute bacterial meningitis
Bacterial Meningitis Symptoms
The diagnosis of bacterial meningitis is made through physical examination and a spinal tap (lumbar puncture or LP) to obtain a sample of the cerebrospinal fluid. Meningitis can lead to a variety of symptoms that present differently in different individuals.
At least one of these three symptoms is present in 99 percent of people with meningitis .
- Neck stiffness (menigismus)
- Altered mental status: Such as confusion and lethargy
Other symptoms or signs of increased intracranial pressure from swelling of the meninges may include the following.
- Sensitivity to light (photophobia)
- Rashes: These are common in several forms of bacterial meningitis.
Symptoms in babies and children
In babies, less specific symptoms may appear, and neck stiffness may be difficult to detect. These include:
- Irritability: A sharp increase in crying and fussiness may be the first sign of infection.
- Tiredness and slowness: The child may appear less active than usual.
- Poor feeding: The child may vomit or refuse food.
- Seizures: These are more common in children with meningitis.
Complications of bacterial meningitis may include :
- Hydrocephalus: Increased fluid surrounding the brain.
- Stroke: Inflammation of arteries and veins in and around the brain can lead to decreased blood flow and damage to the brain.
- Double vision: Inflammation of the abducens nerve can impair eye movements.
- Hearing loss: Due to damage to the ear and auditory nerve.
- Brain herniation: Increased pressure in the skull can lead the brain to be pushed against solid structures in the skull. This is the most common cause of death during acute meningitis.
- Systemic complications: These may include sepsis (body inflammation and organ damage), disseminated intravascular coagulation (a blood clotting disorder), and hyponatremia (low levels of sodium in the blood).
Bacterial Meningitis Causes
Infants and young people, especially those exposed to group settings such as daycare or dormitories, are the most susceptible to contracting meningitis. However, anyone can become infected. Disease-causing bacteria can be transmitted through casual contact such as coughing, sneezing, or kissing, or by eating contaminated food.
Meningitis is caused by bacteria in the central nervous system (CNS). In the U.S., the most common causes of bacterial meningitis include [3,4]:
- Streptococcus pneumonia (S. pneumo): Common cause among all age groups and more commonly causes pneumonia and sinus infections.
- Group B Streptococcus (GBS): Common cause among all age groups.
- Neisseria meningitides (N. meningitides): Common cause among adolescents and adults that has led to epidemics in communal settings.
- Haemophilus influenza (Hib): Common cause among children and the elderly.
- Listeria monocytogenes (Listeria): Common cause among newborns and the elderly, and the bacteria can be found in cheese and meat products.
How spread occurs
Most bacteria are spread in the community and then reach the central nervous system via the bloodstream or through defects in the skull or spine [2,3].
- Person-to-person: Many of the bacteria above can be carried by people who never become sick, but still spread the bacteria to others. This can occur during childbirth, in which mothers can pass GBS or E. coli to babies; coughing and sneezing can spread S. pneumo and Hib; saliva and spit can spread N. meningitis due to close living spaces or kissing.
- Foodborne: E. coli and Listeria can be spread by contaminated food.
Risk factors for bacterial meningitis
The following are the main risk factors for developing meningitis.
- Age: Although meningitis can occur at any point throughout the lifespan, babies are at highest risk.
- Skipping vaccinations: Child and adult vaccines are critical to reducing the risk of this potentially deadly condition .
- Communal settings: Meningitis can spread among large groups, such as college students, military bases, and during pilgrimages such as in Mecca .
- Medical conditions: Certain medical conditions that compromise immunity, such as HIV/AIDS, organ transplants, alcoholism, diabetes, and sickle cell disease, increase the risk of developing bacterial meningitis . Neurosurgical procedures, such as ventricular shunts, can also predispose people to meningitis .
Treatment Options and Prevention for Bacterial Meningitis
The best course of treatment can be determined by your medical provider. Prompt care is important as the likelihood of developing complications, such as hearing loss, increases if treatment is delayed.
The following treatment options will likely be started promptly once you seek attention to address various symptoms.
- Antibiotics: Intravenous antibiotics must be started as soon as possible to control the infection. Antibiotics may be adjusted when the precise causative organism is identified.
- Steroids: Early treatment with steroids to reduce inflammation around the brain has been found effective in reducing mortality and neurologic complications in people with S. pneumo meningitis .
- Intravenous fluids: IV fluids are often offered to prevent dehydration and electrolyte abnormalities .
Methods for preventing the contraction and spread of meningitis include the following.
- Vaccines: Vaccines have contributed to a significant reduction in cases of severe meningitis over the decades. Several dangerous causes of meningitis are preventable with vaccines, including N. meningitidis, S. pneumo, and Hib. Ask your physician if you and/or your child are up to date with recommended vaccines.
- Prenatal care: Pregnant women can reduce their newborn's risk of meningitis by getting tested for GBS during the third trimester and by avoiding certain foods during pregnancy, such as unpasteurized dairy products, luncheon meat, and smoked seafood [3,5].
- Prophylactic antibiotics: Physicians or your public health department may recommend that close contacts of people who develop meningitis, such as roommates or family members, take a short course of antibiotics to prevent themselves from developing the infection. This recommendation varies depending on the causative bacterium .
- Practice good hygiene: Careful hand washing before eating and after using the bathroom and covering your mouth and nose when you sneeze or cough can help protect you and others from infections .
Most people recover from meningitis, but without prompt treatment, death can occur within hours of developing symptoms . Prognosis is better among younger individuals .
Questions Your Doctor May Ask to Determine Bacterial Meningitis
To diagnose this condition, your doctor would likely ask about the following symptoms and risk factors.
- Has your fever gotten better or worse?
- Do you have a cough?
- Do you look very sick (pale, sweaty, sleepy, unusual etc.)?
- Is your fever constant or come-and-go?
- How severe is your fever?
The above questions are also covered by our A.I. Health Assistant.
- Bamberger DM. Diagnosis, initial management, and prevention of meningitis. Am Fam Physician. 2010;82(12):1491-8. AAFP Link
- Greenlee JE. Acute bacterial meningitis. Merck Manual Professional Version. Updated November 2017. Merck Manuals Link
- Bacterial meningitis. Centers for Disease Control and Prevention. Updated January 25, 2017. CDC Link
- Meningitis diagnosis & treatment. Mayo Clinic. Published September 11, 2018. Mayo Clinic Link
- Listeria and pregnancy. American College of Obstetricians and Gynecologists. Published June 2018. ACOG Link
- Bhimraj A. Acute community-acquired bacterial meningitis in adults: An evidence-based review. Cleveland Clinic Journal of Medicine. 2012;79(6):393-400. MDedge Link