What Is Meningitis?
Meningitis is a potentially life-threatening infection of the meninges, the tough layer of tissue that surrounds the brain and the spinal cord. If not treated, meningitis can lead to brain swelling and cause permanent disability, coma, and even death.
Meningitis has various causes, including bacterial infection (the most serious cases), viral infection, fungal infection, reactions to medications, and environmental toxins such as heavy metals. Although bacterial and fungal meningitis require extended hospitalization, meningitis caused by viruses can often be treated at home and has a much better outcome.
- Bacterial meningitis
- The most serious form of meningitis is bacterial.
- Even with treatment, bacterial meningitis can be fatal some of the time. If bacterial meningitis progresses rapidly, in 24 hours or less, death may occur in more than half of those who develop it, even with proper medical treatment.
- Viral meningitis
- Determining how many people get viral meningitis is difficult because it often remains undiagnosed and is easily confused with the flu.
- The prognosis for viral meningitis is much better than that for bacterial meningitis, with most people recovering completely with simple treatment of the symptoms. Because antibiotics do not help viral infections, they are not useful in the treatment of viral meningitis.
- Fungal meningitis
- Fungal meningitis is a serious form of meningitis that is normally limited to people with impaired immune systems.
- In 2012, fungal meningitis was linked to a contamination in a specific steroid product, methylprednisolone, manufactured in a single pharmacy and injected in the spine of people suffering from low back pain.
- Aseptic meningitis
- Aseptic meningitis is a term referring to the broad category of meningitis that is not caused by bacteria.
- Approximately 50% of aseptic meningitis is due to viral infections.
- Other less common causes include
What Are Causes and Risk Factors of Meningitis in Adults?
Usually, the brain is protected naturally from the body's immune system by the barrier that the meninges create between the bloodstream and the brain itself. Normally, this helps prevent the body from mounting an immune reaction to attack itself. In meningitis, however, this can become a problem.
Once bacteria or other organisms have found their way to the brain, they are somewhat isolated from the immune system and can spread. However, when the body eventually begins to fight the infection, the problem can worsen.
As the body tries to fight the infection, blood vessels become leaky and allow fluid, white blood cells, and other infection-fighting particles to enter the meninges and the brain. This causes brain swelling and can eventually lead to decreased blood flow to parts of the brain, worsening the symptoms of infection.
- Meningitis is usually caused by one of a number of bacteria. The most common is Streptococcus pneumoniae. Neisseria meningitidis can cause outbreaks in crowded conditions, such as college dormitories or military barracks. Haemophilus influenzae type B (Hib) can also cause meningitis in adults and children. Meningitis in children is becoming less common because children now receive the Hib vaccine in infancy as well as the pneumococcal vaccine (Prevnar).
- Bacterial meningitis can occur for a number of reasons. Often it is the result of an infection by bacteria that already live in the nose and mouth. The bacteria enter the blood and become lodged in the brain's outer covering, the meninges.
- Meningitis can also be caused by the spread of an infection occurring near the brain, such as from the ears or the sinuses. It is also an occasional complication of brain, head, or neck surgery.
- The average age for meningitis is 25 years, and meningitis affects both men and women equally. For unclear reasons, African-Americans seem to develop meningitis more frequently than do people of other races.
- Risk factors that place people at higher risk for bacterial meningitis include the following:
- Adults older than 60 years of age
- Children younger than 5 years of age
- People with alcoholism
- People with sickle cell anemia
- People with cancer, especially those receiving chemotherapy
- People who have received transplants and are taking drugs that suppress the immune system
- People with diabetes
- Those recently exposed to meningitis at home
- People living in close quarters (military barracks, dormitories)
- IV drug users
- People with shunts in place for hydrocephalus
- Fungal meningitis is a very serious and rare cause of meningitis. Typically limited to people who have had surgical procedures or have impaired immune systems due to cancer and other diseases affecting immune function, the 2012 outbreak of fungal meningitis was linked to a specific procedure using a specific steroid medication.
- Other forms of steroids and steroid injections outside of the spine have not been implicated in fungal meningitis.
- Fungal meningitis is not contagious and cannot be spread from person to person.
Think you know a lot about meningitis, an infection of the meninges? Test your meningitis IQ with our quiz.
What Are Symptoms and Signs of Meningitis in Adults?
About 25% of those who develop meningitis have symptoms that develop over 24 hours. The remainder generally become ill over one to seven days. Occasionally, if someone has been on antibiotics for another infection, the symptoms can take longer to develop or may be less intense. If someone is developing fungal meningitis (most commonly someone who is HIV positive), the symptoms may take weeks to develop.
The classic symptoms of meningitis are fever, headache, and stiff neck. Unfortunately, not everyone with meningitis has all of these symptoms. Only approximately 45% of people with meningitis have all three of these classic signs. Almost everyone, however, has at least one of the classic symptoms.
- Classic symptoms
- Headache occurs in most people with meningitis
- Stiff neck occurs in a majority of people with meningitis
- Fever and chills occur in most people with meningitis
- Vomiting occurs in many of people with meningitis
- Extreme sensitivity to bright lights (photophobia)
- History of a recent upper respiratory infection (for example, cold, sore throat)
- Less common symptoms
- Localized weakness or loss of strength or sensation, especially in the face
- Joint swelling and pain in one or more joints
- A new rash that often looks like bruises or tiny red spots
When Should People Seek Medical Care for Meningitis?
Because meningitis can be so serious, seeking immediate medical care is essential if one experiences the symptoms described above and think that meningitis could be the cause. Fever, headache, neck stiffness, and any change in a person's thinking (for example, unusually sleepy, acting "goofy," talking nonsense) together suggest meningitis.
In all cases, meningitis is a disease that should be diagnosed and treated immediately. This condition is an emergency that is usually best evaluated in an emergency department, rather than a doctor's office.
If transportation is not available, calling an ambulance is best. Call 911 immediately if you are having difficulty breathing. If friends or family members notice a person experiencing confusion or seizures, or the person is difficult to awaken, they should call 911 immediately.
How Do Health Care Professionals Diagnose Meningitis in Adults?
Rapid evaluation and entry into the emergency department begin upon arrival when you are identified as possibly having meningitis.
Often, you are placed in an isolation room to protect staff and others from infection. Additionally, a mask may be placed over your nose and mouth to further prevent the spread of infection.
- Examination: The doctor performs an early examination to determine if help is needed with breathing or blood pressure. The doctor then checks your blood pressure, pulse, and temperature.
- Testing: Once the doctor examines you and learns of your symptoms, further evaluation depends on the doctor's assessment of the likelihood of meningitis. If the doctor suspects bacterial meningitis, he or she may order the following:
- Antibiotics may be given early in the evaluation.
- A CT scan may be performed. This can sometimes determine if the brain is infected or has an abscess.
- Blood is drawn to check the white and red blood cell counts.
- A chest X-ray film may be obtained to look for signs of pneumonia or fluid in the lungs.
- Other tests may be performed to look for other sources of infection.
- Spinal tap: A spinal tap, or lumbar puncture, is necessary to diagnose meningitis. The results of the spinal tap are essential to help the doctor determine both the presence and then the type of meningitis. Correctly diagnosing meningitis is absolutely essential to guide treatment decisions. If you are too sick for a spinal tap, you will be treated with antibiotics on the assumption that you have meningitis. The spinal tap will be done when your condition improves.
- Cerebrospinal fluid is obtained through a spinal tap. This fluid surrounds and cushions the brain and the spinal cord. The fluid is analyzed in the lab for things like the presence of white and red blood cells and protein and glucose (sugar) levels. The doctor then interprets the test results to determine if meningitis is present. The test results can also indicate if the meningitis is due to a bacterial infection, fungal infection, or a virus.
- To obtain the fluid, you are given an injection of lidocaine (Anestacaine, UAD Caine, Xylocaine HCl, Xylocaine-MPF), a local anesthetic similar to Novocaine used by dentists. A small needle is placed in the lower back, around the small of the back, to obtain the fluid.
- Although the spinal tap can sometimes be uncomfortable, it is generally not very painful. The main complications of the procedure are headache, which occasionally occurs, and infection, which is extremely rare.
- Because the results of the spinal tap can take up to several hours to return, the treatment often begins before the results are available. The doctor focuses early treatment on a medical opinion of the most likely cause based on your symptoms and physical examination findings.
What Types of Health Care Professionals Diagnose and Treat Meningitis?
Although either a primary care or pediatric doctor may occasionally begin treatment, most individuals get their first treatments in an emergency center by emergency medicine doctors. Patients then may be further treated by critical care specialists, infectious disease specialists, and hospitalists.
Are There Home Remedies for Meningitis in Adults?
Prompt diagnosis and treatment of meningitis is essential. Therefore, if you suspect that you or someone you know has meningitis based on the symptoms, seeking immediate medical attention is critical. If you cannot take the person to the hospital, it is advisable to call an ambulance.
- Emergency care: While taking someone to the hospital's emergency department or waiting for an ambulance, basic treatment involves these procedures:
- Give acetaminophen (Tylenol) for fever.
- Keep the person in a darkened, quiet area.
- If the person is vomiting, lay the person on one side to prevent him or her from inhaling vomit.
- Home care: Home care is only recommended if the person has mild viral meningitis, which can only be determined by a lumbar puncture. It is not appropriate to presume that symptoms of meningitis are due to a virus and to postpone medical care. All cases of meningitis need to be evaluated immediately in an emergency care setting. If the doctor determines that the person is suffering from mild viral meningitis, medications may be needed for control of headache and fever. This is often accomplished with acetaminophen (Tylenol) or stronger pain medications. Antibiotics are not helpful for viral meningitis.
- If someone is sent home from the doctor with viral meningitis, it is essential for that person to be seen by his or her regular doctor in the next one to two days for a checkup.
- When someone with viral meningitis is treated at home, watching for signs of a worsening condition is essential. If any of these occur, seek the care of a doctor immediately:
- Profuse or uncontrollable vomiting
- Worsening headache or fever
- Weakness or numbness of any extremities
- Difficulty speaking, swallowing, or walking
- Confusion or excessive sleepiness
What Is the Treatment for Meningitis in Adults?
Hospitalization for meningitis depends on the cause.
If you appear to have viral meningitis, treatment is usually less aggressive and consists of measures to make you more comfortable. Viral meningitis is often treated at home with acetaminophen (Tylenol) and other pain medications. Antibiotics are not helpful in treating viral meningitis.
If you have bacterial or fungal meningitis, you are often admitted to the intensive-care unit, for either a short period of observation or a longer period if you are more ill. Care of bacterial meningitis begins by ensuring that your breathing and blood pressure are adequate.
- An IV line is inserted and fluids are given.
- You are placed on a heart monitor.
- Intravenous antibiotics may be given.
Steroids may be given to try to decrease the severity of the disease.
- If you are extremely ill, more aggressive medical care may be given.
- A breathing tube (intubation) may be inserted to help with breathing.
- Larger IV lines may be inserted in the groin, the chest, or the neck. Medications may be given to improve blood pressure and to stop seizures.
- A tube (catheter) may be placed in the bladder to check your hydration (or fluid status).
If the diagnosis is uncertain, or if you have recently been on antibiotics, you may be admitted to the hospital for observation and treatment until the diagnosis is certain. This may require another spinal tap in 12-24 hours for reevaluation.
How Do People Transmit Meningitis?
Bacterial and viral meningitis can be spread to others, however both viral and bacterial meningitis are not as contagious as colds or the flu.
- Transmission of meningitis requires close contact with respiratory droplets or saliva such as through kissing, sneezing, or coughing.
- Sharing drinks, utensils, or toothbrushes with an infected patient can also lead to transmission.
- Sharing a cigarette theoretically may lead to transmission also.
- Simply being in the same room with someone with meningitis is not enough to transmit the disease.
Is It Possible to Prevent Meningitis in Adults?
- Antibiotics can be given to help prevent meningitis if a person has had the following:
- Close contact with someone who has meningitis
- Prolonged close contact (those who live, go to school, or are in jail with a person with meningitis)
- Exposure to mouth, nose, or lung secretions (for example, kissing, mouth-to-mouth resuscitation, sharing drinks or utensils)
- Even if antibiotics are given for prevention, anyone who has been exposed to someone with meningitis needs to seek medical attention if sore throat, fever, headache, rash, or neck stiffness develops.
- Preventive antibiotics are not necessary for all cases of meningitis and are generally not necessary unless the doctor suspects or confirms that the meningitis is caused by the bacteria Neisseria meningitidis.
- Incoming college freshmen who live in close quarters, such as dormitories, may be given a vaccine to prevent this type of bacterial meningitis.
- The Advisory Committee on Immunization Practices of the U.S. Centers for Disease Control and Prevention (CDC) says this group is at a small but somewhat increased risk for meningococcal meningitis.
- Other college students may also elect to have the single-dose shot.
Are There Meningitis Vaccinations?
- A vaccine is available for meningitis caused by Neisseria meningitides. Meningococcal conjugate vaccine is routinely recommended for all 11- through 18-year-olds and is often administered as part of a well-child checkup at 11-12 years of age.
- The CDC has recommended this vaccine for the following groups of people:
- College freshmen living in dormitories
- Military recruits
- Those whose spleen has been removed or is damaged for any other reason to due to disease or injury
- Those with a specific blood problem called "complement deficiency"
- Travelers to areas where meningitis is common
- The pneumonia vaccine may provide protection against some types of meningitis caused by Streptococcus pneumoniae. It is recommended primarily for people at risk for pneumonia but may provide some protection from meningitis caused by Streptococcus pneumoniae as well. People who may benefit from the pneumonia vaccine include all people over 65 years of age, as well as
- people with chronic lung disease,
- debilitated people,
- people with sickle cell anemia,
- people who have had their spleen removed.
- Although not normally given to adults, the Haemophilus influenza type B (Hib) vaccine is routinely given to children and is effective in preventing meningitis due to this type of bacteria. It is not normally given to adults but may be useful for people with the following:
- Sickle cell anemia
- Removal of the spleen
- Bone marrow transplant
- Receiving chemotherapy for cancer
What Is the Prognosis of Meningitis in Adults?
The prognosis of meningitis depends on the severity and the cause of the illness.
- In those with severe bacterial meningitis or a very fast onset of illness, the death rate can be as high as 90%. If the person survives, even with proper treatment, long-term disabilities can result, including deafness, seizures, paralysis, blindness, or loss of limbs.
- In those with less severe cases of bacterial meningitis, the death rate can still approach 25%. Long-term disabilities are possible. The person may require a prolonged period of hospitalization and rehabilitation.
- For a person with viral meningitis, full recovery can take place in seven to 10 days.
Where Can People Find More Information on Meningitis in Adults?
Meningitis Foundation of America
6610 North Shadeland Avenue, Suite 200
Indianapolis, IN 46220-4393
Centers for Disease Control and Prevention
1600 Clifton Road
Atlanta, GA 30333
Meningitis Research Foundation
Reviewed on 9/11/2017
Hasbun, R. "Meningitis." June 18, 2017. Medscape. <http://emedicine.medscape.com/article/232915-overview>.
United States. Centers for Disease Control and Prevention. "Multistate Outbreak of Fungal Meningitis and Other Infections –Healthcare Facilities." Oct. 29, 2015. <http://www.cdc.gov/hai/outbreaks/meningitis-facilities-map.html>.