What is meningitis?
Meningitis is inflammation or swelling of the meninges. The meninges are membranes that surround the brain and spinal cord, or the central nervous system. Cerebrospinal fluid (CSF) floats between the meninges and the brain and spinal cord. It is a clear liquid that bathes the brain and spinal cord and provides a layer of cushioning for them.
Meningitis usually occurs when a microorganism infects the CSF. When an infection develops, it triggers swelling of the membranes or meninges. Bacteria and viruses are the most common pathogens that cause meningitis. However, non-infectious conditions can also cause swelling of the meninges, including cancer and certain inflammatory diseases. Spinal meningitis is another name for meningitis.
Anyone can get meningitis, but some people are more at risk than others for the different types of meningitis. Children younger than 5 years of age and people with weakened immune systems are at highest risk for developing viral meningitis. Babies have a higher risk of bacterial meningitis than other age groups. However, young adults also have a higher risk when they live in crowded conditions, such as college campuses and military bases.
Typical symptoms of meningitis include a high fever, severe headache, nausea, vomiting, and stiff neck. Treatment of meningitis varies depending on the type of meningitis. Viral meningitis usually gets better on its own with only symptomatic treatment, including rest, fluids, and over-the-counter pain relievers. It can take about 7 to 10 days to recover. However, bacterial meningitis requires antibiotics to fight the infection and potent anti-inflammatory drugs to prevent complications, such as permanent brain damage or paralysis.
Meningitis is a serious disease that can be life threatening due to dangerous complications, such as shock and coma. Seek prompt medical care if you have been exposed to someone who has meningitis. Seek immediate medical care (call 911) if you, or someone you are with, have symptoms of meningitis, such as high fever, stiff neck, change in consciousness, seizure, and a rash of tiny purple or red spots.
What are the types of meningitis?
Doctors broadly classify meningitis as bacterial meningitis or aseptic meningitis. Aseptic meningitis means there is no evidence of bacterial growth when a laboratory examines a sample of cerebrospinal fluid (CSF). Most cases of aseptic meningitis are viral. However, doctors cannot find an underlying cause for the inflammation in nearly 19% of meningitis cases.
Bacterial meningitis often occurs suddenly—or acutely. Because of this, you may hear it called acute bacterial meningitis. It is caused by a bacterial infection and is generally the most serious type of meningitis. It can become life threatening very quickly and requires emergency medical attention.
Chronic meningitis is a long-term disease and develops over weeks or months. It is usually caused by slow-growing microorganisms, cancer, or autoimmune disease.
Fungal meningitis is rare. It is a form of chronic meningitis due to an infection with fungi in the environment. Having certain medical conditions, such as HIV or cancer, increases the risk of fungal meningitis.
Non-infectious meningitis is not the result of an infection of the meninges or CSF. Instead, it has various causes, including drug reactions, brain surgery, head injury, cancer, or inflammatory conditions, such as systemic lupus erythematosus (SLE) or sarcoidosis.
Viral meningitis occurs from infections with a virus. It is usually less severe than bacterial meningitis and most people recover without problems within 7 to 10 days. Viral meningitis is the most common form of meningitis in the United States.
Other types of meningitis
Meningitis can also be the result of a parasitic infection or an amebic infection. These types of meningitis are much less common than bacterial and viral meningitis. Amebic meningitis is extremely rare in the United States.
Is meningitis contagious?
Some types of meningitis are contagious and spread from person to person. Non-infectious forms of meningitis are not contagious. Fungal, parasitic and amebic meningitis do not have person-to-person transmission. At-risk people get fungal meningitis from inhaling fungal spores in the environment. Parasitic meningitis occurs after someone consumes contaminated food. Amebic meningitis, though very rare, usually develops after swimming in contaminated water. Generally, you can’t pass these types of meningitis to another person.
The viruses and bacteria that cause meningitis are contagious. They can spread into the air by coughing and sneezing. Once pathogens are airborne, they can be picked up by anyone who breathes them into their respiratory tract. Some of these pathogens can spread through contact with contaminated body fluids, such as mucus. Once in the body, the pathogens enter the bloodstream where they are carried to the central nervous system (CNS). In the CNS, they multiply and cause infection of cerebrospinal fluid and inflammation of the meninges.
With viral meningitis, spreading the virus to another person doesn’t necessarily mean the person will also get meningitis. According to the CDC (Centers for Disease Control and Prevention), only a small number of people who contract these viruses will develop meningitis. Bacterial meningitis is much more likely to spread from person to person resulting in meningitis outbreaks. Neisseria meningitidis, which causes meningococcal disease, is a common cause of bacterial meningitis outbreaks.
What are the symptoms of meningitis?
Some meningitis symptoms are the same no matter what is causing the inflammation. However, symptoms can vary somewhat when an infection is the cause. It depends on the specific pathogen causing the infection. Symptoms of acute bacterial meningitis are generally the most severe. Other forms of meningitis, such as chronic meningitis and viral meningitis, have similar but milder symptoms. Symptoms can also vary with age (see Meningitis in Children later in this article).
First signs of meningitis
The first signs of meningitis are often similar to other diseases, such as flu. They tend to begin quickly over hours to days and include:
- Fever, which can come on suddenly and be high
- Headache, which can be severe or very different from a normal headache
- Lack of appetite or thirst
- Nausea and vomiting, which may accompany the headache
- Sleepiness or fatigue
- Stiff neck
Meningitis skin rash
A skin rash may or may not be present with the other symptoms of meningitis. In general, it is a splotchy rash with red or purplish spots on the skin. In some cases, the spots can be very tiny, like pinpricks. In other cases, the spots are larger and resemble bruises. A rash most often occurs with bacterial meningitis from meningococcal bacteria (Neisseria meningitidis). This is an important clinical sign that immediate medical attention is required.
When to see a doctor if you have symptoms of meningitis
Only a doctor can determine if you have viral or bacterial meningitis. Seek immediate medical care for any meningitis symptoms. Bacterial meningitis can quickly lead to serious complications and become life threatening. Getting a quick diagnosis (with blood tests, imaging and perhaps spinal tap) and starting treatment right away can make the difference between recovering smoothly and suffering with chronic disabilities, such as hearing loss.
Serious symptoms that indicate a life-threatening condition
Symptoms of acute bacterial meningitis, the most serious form of meningitis, can progress rapidly and dramatically within minutes to hours. Bacterial meningitis can lead to death within days. Seek immediate medical care (call 911) if you or your child, or someone you are with, have any of these symptoms:
- High fever (higher than 101 degrees Fahrenheit)
- Rash of tiny purple or red spots
- Sensitivity to light
- Severe or unrelenting headache or severe neck stiffness
What causes meningitis?
The most common cause of meningitis is a viral infection, specifically with a member of the enterovirus group. Enteroviruses are very common viruses that spread by coughing, hand-to-mouth contact, and contact with fecal matter from an infected person, such as changing the diaper of a baby infected with the virus. In most cases, enteroviruses cause a cold-like illness. However, in some people, the virus spreads to the cerebrospinal fluid (CSF) and causes meningitis.
Other viruses that can cause viral meningitis include:
- Arboviruses, such as West Nile virus
- Herpesviruses, such as Epstein-Barr virus, herpes simplex viruses, and varicella-zoster
The second most common cause of meningitis is a bacterial infection. Streptococcus pneumoniae is the most common cause of bacterial meningitis in the United States. It can also cause pneumonia and ear or sinus infections. Neisseria meningitidis is the second most common cause. It is a highly contagious bacterium that most often affects young adults who live in group settings.
These bacteria spread from person to person through coughing, sneezing and kissing. Once in the body, the bacteria can spread from the respiratory tract to the bloodstream where they are carried to the central nervous system (CNS, which includes the brain and spinal cord). In the CNS, they multiply and infect the CSF, causing inflammation of the meninges.
Other bacterial causes of meningitis include:
- Group B Streptococcus, which can spread from mothers to babies during birth
- Haemophilus influenzae, which is no longer a leading cause of meningitis due to effective Hib vaccines
- Listeria monocytogenes, which is a risk when eating unpasteurized cheeses, hot dogs, and lunchmeat
Meningitis can also be caused by fungi, including Cryptococcus, Histoplasma, Blastomyces and Coccidioides. The fungus Candida can cause meningitis in certain people who are at risk, such as people with compromised immune systems.
The amoeba that can cause meningitis is Naegleria fowleri. This organism lives in soil and warm freshwater. When it causes meningitis, the disease is usually devastating and fatal. Fortunately, there are usually less than 10 cases per year in the United States.
Non-infectious causes of meningitis include:
- Brain surgery or head injury
- Certain inflammatory conditions, such as systemic lupus erythematosus (SLE) and sarcoidosis
- Reactions to certain drugs, such as chemotherapy, or vaccines
How is meningitis diagnosed?
Your doctor may suspect meningitis based on the signs and symptoms you display. To know for sure what is causing meningitis, the following tests may be necessary:
- Blood culture to see if microorganisms are in the blood and what kind they are. It involves taking a blood sample and using a special laboratory dish to grow any bacteria that are present.
- Imaging exams to look for signs of infection and inflammation. This can include X-ray, CT (computed tomography), or MRI (magnetic resonance imaging).
- Spinal tap to look for signs of infection in the CSF and determine whether it is a bacterial or viral infection. An examination of the CSF is the only way to reach a definitive diagnosis of meningitis and find out the most likely cause of it. Utilizing local anesthesia, it involves inserting a needle through the lower back into the spinal canal to withdraw a sample of CSF. Another name for this test is a lumbar puncture.
What are the risk factors for catching meningitis?
Meningitis can occur in any age group or population. However, viral meningitis most often occurs in children younger than 5 years. Bacterial meningitis is more common in young adults under age 20. A number of factors increase the risk of catching meningitis, although not all people with risk factors will get meningitis.
Meningitis risk factors include:
- Exposure to a person with meningitis
- Living in group settings or crowded conditions, such as military barracks, prisons, refugee camps, day care centers, or college dormitories
- Not completing the recommended childhood or adult vaccination schedule
- Poor hygiene, such as not washing your hands frequently and thoroughly, or sharing unwashed drinking glasses, water bottles, dishware, or personal items, such as lip balm and toothbrushes
- Pregnancy, which increases susceptibility to infection with Listeria monocytogenes
- Weakened immune system due to age, medications, or medical conditions, such as HIV and cancer
Reducing your risk of meningitis
You can lower your risk of catching or spreading meningitis by:
- Avoiding contact with a person who has meningitis, or anyone who is experiencing signs of an infectious disease, such as fever, cough, sore throat, muscle aches, vomiting, diarrhea, or unusual rash or fatigue
- Avoiding touching the eyes, nose and mouth, which can transmit viruses and bacteria from the hands into the body
- Covering the mouth and nose with the elbow (not the hand) or a tissue when sneezing or coughing
- Getting meningitis vaccinations as recommended by your healthcare provider
- Not sharing unwashed drinking glasses, water bottles, dishware, or personal items, such as lip balm and toothbrushes
- Using appropriate antimicrobial cleaners to clean hands and surfaces
- Washing hands with soap and water for at least 15 seconds several times throughout the day and after contact with a person who has meningitis, such as living in the same household
What vaccines are available to prevent meningitis?
Vaccines are available to protect against some types of bacterial and viral meningitis including:
Haemophilus influenzae type b (Hib) vaccine
The Hib vaccine protects against Haemophilus influenzae bacterial meningitis. It is part of the recommended schedule of childhood vaccines in the United States. Adults with certain medical conditions may also need a Hib vaccine.
Meningococcal vaccines protect against any disease caused by Neisseria meningitidis. There are two types of meningococcal vaccines:
- Meningococcal conjugate vaccine (MenACWY): All children should receive one dose between ages 11 and 12 with a booster dose at age 16.
- Serogroup B meningococcal vaccine (MenB): Some teens and young adults should receive this vaccine between ages 16 and 18. Your doctor can help you determine whether this vaccine is right for you.
Pneumococcal vaccines protect against disease from Streptococcus pneumoniae (this bacterial species is not the same as the strep bacteria that cause strep throat). There are two types of pneumococcal vaccines:
- Pneumococcal conjugate vaccine (PCV13): This vaccine is part of the regular schedule of childhood vaccines in the United States.
- Pneumococcal polysaccharide vaccine (PPSV23): This vaccine is for older children and adults who are at risk of pneumococcal disease.
How is meningitis treated?
Treatment of meningitis varies depending on the type of meningitis, your age, and other factors. General treatment of all forms of meningitis includes:
- Acetaminophen (Tylenol) or ibuprofen (Motrin, Advil) and other medications for pain and fever
- Close monitoring and possibly treatment of people who have had close contact with a person with meningitis, even if there are no symptoms
- Fluid administration by mouth or intravenously
Treatment of acute bacterial meningitis
Acute bacterial meningitis is a medical emergency, because it can rapidly result in permanent, serious complications and death within days. Treatment includes:
- Hospitalization, generally in an intensive care setting
- Immediate administration of IV (intravenous) antibiotics
- Intensive monitoring for and treatment of potential complications, such as brain swelling, seizures, and coma. Life support measures may also be necessary.
Treatment of viral meningitis
Most people with viral meningitis get better on their own in about 7 to 10 days with only general treatments. Some types of viral meningitis, such as herpes virus meningitis, are treated with antiviral drugs. Antibiotics are generally not given because they are not effective in treating viral meningitis. However, in some cases, antibiotics may be administered as a precaution if the type of meningitis cannot be determined quickly or if it is suspected that the meningitis is due to a bacterial infection.
Treatment of non-infectious meningitis
Treatment of non-infectious meningitis depends on the underlying cause. Often, treating the disease causing the meningitis will resolve the problem. In the meantime, doctors may use corticosteroids to control the inflammation affecting the meninges.
What are the possible complications of meningitis?
Meningitis, especially acute bacterial meningitis, can lead to serious and life-threatening complications. In some cases, death can occur in a matter of days. You can help minimize your risk of complications by following the treatment plan you and your healthcare professional design specifically for you. Complications of meningitis include:
- Disseminated intravascular coagulation (DIC), a blood-clotting disorder
- Permanent neurological damage, such as blindness, hearing loss, brain damage, or paralysis
Meningitis in Children
Both children and adults can get meningitis. While there are many similarities, there are also differences between adults and children with meningitis. The main differences lie in the symptoms to look for and the possible causes of meningitis.
Meningitis is children can be scary because it is not always easy to tell when a baby or child is sick. Older children will have symptoms very similar to symptoms in adults. However, symptoms may appear different in babies and young children.
Symptoms in babies can include:
- Bulging fontanelle (soft spot) or arching of the back
- Feeding poorly or vomiting
- Fever with or without a splotchy rash
- Inconsolable crying or a very high-pitched cry
- Irritability, change in temperament, or sleeping more than usual
Symptoms in toddlers and young children:
- Changes in consciousness or seizures
- Confusion, irritability, or excessive sleepiness
- Fever with or without a splotchy rash
- Nausea and vomiting or refusing to eat
- Neck stiffness or complaining that eyes are sensitive to light
Like adults, the most common causes of meningitis in children are bacterial and viral infections. These infections usually start in the respiratory tract as a cold or sinus or ear infection. From the respiratory tract, the pathogen causing the infection can travel to the bloodstream and central nervous system, causing meningitis.
Viral meningitis is more common than bacterial meningitis in children. It is also usually less severe than bacterial meningitis. Non-infectious meningitis is less common in children because the underlying causes—including lupus, brain surgery, and head trauma—are less common in this age group.
Bacterial meningitis is the most serious and potentially deadly form of the disease. Babies are a high-risk group for contracting bacterial meningitis. The most common bacteria causing meningitis can vary by age group. According to the CDC (Centers for Disease Control and Prevention), childhood causes of bacterial meningitis are:
- Newborns: Group B Streptococcus, S. pneumoniae, L. monocytogenes, E. coli
- Babies and children: S. pneumoniae, N. meningitidis, H. influenzae type b (Hib), group B Streptococcus
Children younger than 5 years are one of the high-risk age groups for viral meningitis. Babies younger than 1 month old are at high risk of having severe cases of viral meningitis. Enteroviruses are the most common cause of viral meningitis. Other viruses that can cause meningitis include:
- Arboviruses, such as West Nile virus
- Herpesviruses, such as Epstein-Barr virus, herpes simplex viruses, and varicella-zoster
How to test for meningitis in children
Testing for meningitis in babies and children is the same as for adults. After examining your child, the doctor may order the following tests for meningitis:
- Blood culture to see if microorganisms are in the blood and what kind they are
- Imaging exams like X-ray, CT (computed tomography), or MRI (magnetic resonance imaging) to look for signs of infection and inflammation
- Spinal tap (lumbar puncture) to look for signs of infection in the cerebrospinal fluid and determine whether it is a bacterial or viral infection. This is the only way to confirm a meningitis diagnosis and its most likely cause.
Treating meningitis in children
Treating meningitis in children is also the same as for adults. Most children will recover from viral meningitis on their own within 7 to 10 days. Your doctor may recommend treating symptoms with acetaminophen (Tylenol) or ibuprofen (Advil, Motrin). Your child will also need plenty of rest and fluids.
To treat bacterial meningitis, your child will need treatment in a hospital. Bacterial meningitis is the most serious form of the disease and can quickly become life threatening. In the hospital, your child will receive IV antibiotics and fluid. Children will also need an IV corticosteroid to reduce swelling and pressure on the brain. This can help reduce the risk of hearing loss and brain damage.
Long-term impacts of having meningitis as a child
Children usually recover from viral meningitis without long-term problems. However, bacterial meningitis can lead to serious and severe complications, including chronic neurologic problems. This includes brain damage, seizures, hearing loss, vision problems, and learning disabilities. Some forms of bacterial meningitis can also damage organs, such as the heart and kidneys. However, most children recover fully when they get a prompt diagnosis and timely treatment. The potential for complications stresses the importance of seeking care right away if you suspect a problem.