What is meningitis?
Encephalitis is an inflammation of the brain.
- Meningitis is an inflammation of the membranes (called meninges) that surround the brain and spinal cord.
- Both infections can be caused by bacteria or viruses and rarely a fungus.
- Headache and fever are the most common symptoms of encephalitis and meningitis. Stiff neck, confusion, or lethargy can also be present.
- The diagnosis is usually made by performing a lumbar puncture (spinal tap).
- A CT scan or MRI of the brain can also be helpful but usually is only done in addition to the spinal tap.
- Treatment depends on identifying the underlying cause. If bacteria are causing the infection, then antibiotics are indicated.
- Anyone experiencing symptoms of encephalitis or meningitis should see a doctor immediately.
- Depending on the organism causing the infection, close contacts can also get sick and need to be evaluated by a health-care professional.
- Basic methods that help to prevent the spread of infections (hand washing and covering ones mouth when coughing) can also help prevent the spread of some forms of meningitis.
- Being up to date on vaccinations will help prevent certain forms of meningitis.
What is encephalitis?
Encephalitis is brain inflammation. There are many types of encephalitis, most of which are caused by infections. Most often these infections are caused by viruses. In addition to infections, encephalitis can also be caused by certain diseases that result in an inflammation of the brain.
What are the symptoms for meningitis?
Early meningitis symptoms may mimic the flu (influenza). Symptoms may develop over several hours or over a few days.
Possible signs and symptoms in anyone older than the age of 2 include:
- Sudden high fever
- Stiff neck
- Severe Headache that seems different than normal
- Headache with Nausea or vomiting
- Confusion or difficulty concentrating
- Sleepiness or difficulty waking
- Sensitivity to light
- No appetite or thirst
- Skin rash (sometimes, such as in meningococcal meningitis)
Signs in newborns
Newborns and infants may show these signs:
- High fever
- Constant crying
- Excessive sleepiness or irritability
- Inactivity or sluggishness
- Poor feeding
- A bulge in the soft spot on top of a baby's head (fontanel)
- Stiffness in a baby's body and neck
Infants with meningitis may be difficult to comfort, and may even cry harder when held.
When to see a doctor
Seek immediate medical care if you or someone in your family has meningitis symptoms, such as:
- Severe, unrelenting headache
- Stiff neck
Bacterial meningitis is serious, and can be fatal within days without prompt antibiotic treatment. Delayed treatment increases the risk of permanent Brain damage or death.
It's also important to talk to your doctor if a family member or someone you work with has meningitis. You may need to take medications to prevent getting the infection.
What are the causes for meningitis?
Viral infections are the most common cause of meningitis, followed by bacterial infections and, rarely, fungal infections. Because bacterial infections can be life-threatening, identifying the cause is essential.
Bacteria that enter the bloodstream and travel to the brain and spinal cord cause acute bacterial meningitis. But it can also occur when bacteria directly invade the meninges. This may be caused by an ear or sinus infection, a skull fracture, or, rarely, after some surgeries.
Several strains of bacteria can cause acute bacterial meningitis, most commonly:
- Streptococcus pneumoniae (pneumococcus). This bacterium is the most common cause of bacterial meningitis in infants, young children and adults in the United States. It more commonly causes pneumonia or ear or sinus infections. A vaccine can help prevent this infection.
- Neisseria meningitidis (meningococcus). This bacterium is another leading cause of bacterial meningitis. These bacteria commonly cause an upper respiratory infection but can cause meningococcal meningitis when they enter the bloodstream. This is a highly contagious infection that affects mainly teenagers and young adults. It may cause local epidemics in college dormitories, boarding schools and military bases. A vaccine can help prevent infection.
- Haemophilus influenzae (haemophilus). Haemophilus influenzae type b (Hib) bacterium was once the leading cause of bacterial meningitis in children. But new Hib vaccines have greatly reduced the number of cases of this type of meningitis.
- Listeria monocytogenes (listeria). These bacteria can be found in unpasteurized cheeses, hot dogs and luncheon meats. Pregnant women, newborns, older adults and people with weakened immune systems are most susceptible. Listeria can cross the placental barrier, and infections in late pregnancy may be fatal to the baby.
Viral meningitis is usually mild and often clears on its own. Most cases in the United States are caused by a group of viruses known as enteroviruses, which are most common in late summer and early fall. Viruses such as herpes simplex virus, HIV, mumps, West Nile virus and others also can cause viral meningitis.
Slow-growing organisms (such as fungi and Mycobacterium tuberculosis) that invade the membranes and fluid surrounding your brain cause chronic meningitis. Chronic meningitis develops over two weeks or more. The symptoms of chronic meningitis — headaches, fever, vomiting and mental cloudiness — are similar to those of acute meningitis.
Fungal meningitis is relatively uncommon and causes chronic meningitis. It may mimic acute bacterial meningitis. Fungal meningitis isn't contagious from person to person. Cryptococcal meningitis is a common fungal form of the disease that affects people with immune deficiencies, such as AIDS. It's life-threatening if not treated with an antifungal medication.
Other meningitis causes
Meningitis can also result from noninfectious causes, such as chemical reactions, drug allergies, some types of cancer and inflammatory diseases such as sarcoidosis.
What are the treatments for meningitis?
The treatment depends on the type of meningitis you or your child has.
Acute bacterial meningitis must be treated immediately with intravenous antibiotics and sometimes corticosteroids. This helps to ensure recovery and reduce the risk of complications, such as brain swelling and seizures.
The antibiotic or combination of antibiotics depends on the type of bacteria causing the infection. Your doctor may recommend a broad-spectrum antibiotic until he or she can determine the exact cause of the meningitis.
Your doctor may drain any infected sinuses or mastoids — the bones behind the outer ear that connect to the middle ear.
Antibiotics can't cure viral meningitis, and most cases improve on their own in several weeks. Treatment of mild cases of viral meningitis usually includes:
- Bed rest
- Plenty of fluids
- Over-the-counter pain medications to help reduce fever and relieve body aches
Your doctor may prescribe corticosteroids to reduce swelling in the brain, and an anticonvulsant medication to control seizures. If a herpes virus caused your meningitis, an antiviral medication is available.
Other types of meningitis
If the cause of your meningitis is unknown, your doctor may start antiviral and antibiotic treatment while the cause is determined.
Treatment for chronic meningitis is based on the underlying cause. Antifungal medications treat fungal meningitis, and a combination of specific antibiotics can treat tuberculous meningitis. However, these medications can have serious side effects, so treatment may be deferred until a laboratory can confirm that the cause is fungal.
Noninfectious meningitis due to allergic reaction or autoimmune disease may be treated with corticosteroids. In some cases, no treatment may be required because the condition can resolve on its own. Cancer-related meningitis requires therapy for the specific cancer.
What are the risk factors for meningitis?
Risk factors for meningitis include:
- Skipping vaccinations. Risk rises for anyone who hasn't completed the recommended childhood or adult vaccination schedule.
- Age. Most cases of viral meningitis occur in children younger than age 5. Bacterial meningitis is common in those under age 20.
- Living in a community setting. College students living in dormitories, personnel on military bases, and children in boarding schools and child care facilities are at greater risk of meningococcal meningitis. This is probably because the bacterium is spread by the respiratory route, and spreads quickly through large groups.
- Pregnancy. Pregnancy increases the risk of listeriosis — an infection caused by listeria bacteria, which also may cause meningitis. Listeriosis increases the risk of miscarriage, stillbirth and premature delivery.
- Compromised immune system. AIDS, alcoholism, diabetes, use of immunosuppressant drugs and other factors that affect your immune system also make you more susceptible to meningitis. Having your spleen removed also increases your risk, and patients without a spleen should get vaccinated to minimize that risk.
Is there a cure/medications for meningitis?
Bacterial meningitis needs to be treated right away or it may result in severe complications, such as brain damage, or become deadly.
Seek emergency medical attention if you think you have a bacterial meningitis infection. Early and effective treatment can save your life and reduce your chance of complications.
Other causes may go away after a few days without treatment. See your doctor as soon as you can if you suspect that you have a meningitis infection caused by a virus or parasite.