Human Diseases and Conditions

What is meningitis?

Meningitis is an inflammation of the membranes (called meninges)
 that surround the brain and spinal cord. Meningitis may be caused by
many different viruses and bacteria. It can also be caused by diseases
that can trigger inflammation of tissues of the body without infection
(such as systemic lupus erythematosus and Behcet's disease

Signs and Symptoms
It's easy to mistake the early signs and symptoms of meningitis
 for the flu (influenza). Meningitis signs and symptoms may develop
 over several hours or over one or two days and, in anyone over the
age of 2, typically include:

• High fever
• Severe headache that isn't easily confused with other types of headache
• Stiff neck
• Vomiting or nausea with headache
• Confusion or difficulty concentrating — in the very young, this may appear as
• inability to maintain eye contact
• Seizures
• Sleepiness or difficulty waking up
• Sensitivity to light
• Lack of interest in drinking and eating
• Skin rash in some cases, such as in viral or meningococcal meningitis

Signs in newbornsNewborns and infants may not have the
 classic signs and symptoms of headache and stiff neck. Instead, signs of
meningitis in this age group may include:

• 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
• Seizures

Infants with meningitis may be difficult to comfort, and may even
cry harder when picked up.
When to see a doctor
Seek medical care right away if you or someone in your family has
signs or symptoms of meningitis, such as:

• Fever
• Severe, unrelenting headache
• Confusion
• Vomiting
• Stiff neck

There's no way to know what kind of meningitis you or your
child has without seeing your doctor and undergoing spinal fluid testing.

• Viral meningitis may improve without treatment in a few days.
• Bacterial meningitis is serious, can come on very quickly and requires
• prompt antibiotic treatment to improve the chances of a recovery without
•  serious complications. Delaying treatment for bacterial meningitis increases
• the risk of permanent
• brain damage or death. In addition, bacterial meningitis can prove fatal in a matter of days.

Also talk to your doctor if a family member or someone you work with has meningitis.
You may need to take medications to prevent getting sick.

Causes
Meningitis usually results from a viral infection, but the cause may also be a bacterial infection. Less commonly, a fungal infection may cause meningitis. Because bacterial infections are the most serious and can be life-threatening, identifying the source of the infection is an important part of developing a treatment plan.
Bacterial meningitis
Acute bacterial meningitis usually occurs when bacteria enter the bloodstream and migrate to the brain and spinal cord. But it can also occur when bacteria directly invade the meninges, as a result of an ear or sinus infection or a skull fracture.
A number of strains of bacteria can cause acute bacterial meningitis. The most common include:

• 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.
• Neisseria meningitidis (meningococcus). This bacterium is another leading cause of bacterial meningitis. Meningococcal meningitis commonly occurs when bacteria from an upper respiratory infection enter your bloodstream. This infection is highly contagious. It affects mainly teenagers and young adults, and may cause local epidemics in college dormitories, boarding schools and military bases.
• Haemophilus influenzae (haemophilus). Before the 1990s, Haemophilus influenzae type b (Hib) bacterium was the leading cause of bacterial meningitis in children. But new Hib vaccines — available as part of the routine childhood immunization schedule in the United States — have greatly reduced the number of cases of this type of meningitis. When it occurs, it tends to follow an upper respiratory infection, ear infection (otitis media) or sinusitis.
• Listeria monocytogenes (listeria). These bacteria can be found almost anywhere — in soil, in dust and in foods that have become contaminated. Contaminated foods have included soft cheeses, hot dogs and luncheon meats. Many wild and domestic animals also carry the bacteria. Fortunately, most healthy people exposed to listeria don't become ill, although pregnant women, newborns and older adults tend to be more susceptible. Listeria can cross the placental barrier, and infections in late pregnancy may cause a baby to be stillborn or die shortly after birth. People with weakened immune systems, due to disease or medication effect, are most vulnerable.

Viral meningitis
Each year, viruses cause a greater number of cases of meningitis than do bacteria. Viral meningitis is usually mild and often clears on its own within two weeks. A group of viruses known as enteroviruses are responsible for about 30 percent of viral meningitis cases in the United States. As many viral meningitis episodes never have a specific virus identified as the cause.
The most common signs and symptoms of enteroviral infections are rash, sore throat, diarrhea, joint aches and headache. These viruses tend to circulate in late summer and early fall. Viruses such as herpes simplex virus, La Crosse virus, West Nile virus and others also can cause viral meningitis.
Chronic meningitis
Chronic forms of meningitis occur when slow-growing organisms invade the membranes and fluid surrounding your brain. Although acute meningitis strikes suddenly, chronic meningitis develops over two weeks or more. Nevertheless, the signs and symptoms of chronic meningitis — headaches, fever, vomiting and mental cloudiness — are similar to those of acute meningitis. This type of meningitis is rare.
Fungal meningitis
Fungal meningitis is relatively uncommon and causes chronic meningitis. Occasionally it can mimic acute bacterial meningitis. 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 drug allergies, some types of cancer and inflammatory diseases such as lupus.

What is the treatment of meningitis?

Antibiotic and/or antiviral medications are considered urgently when the diagnosis of encephalitis or meningitis is suggested. In some situations, anticonvulsants are used to prevent or treat seizures. Sometimes corticosteroids are administered to reduce brain swelling and inflammation. Sedatives may be needed for irritability or restlessness. Additional medications might be used to decrease the fever or treat headaches. The need for hospitalization usually depends on the type of meningitis the patient has and the severity of symptoms.


Treatment & Pharmacology
Your family doctor or pediatrician can diagnose meningitis based on a medical history, a physical exam and certain diagnostic tests. During the exam, your doctor may check for signs of infection around the head, ears, throat and the skin along the spine. You or your child may undergo the following diagnostic tests:

• Blood cultures. Blood drawn from a vein is sent to a laboratory and placed in a special dish to see if it grows microorganisms, particularly bacteria. A sample may also be placed on a slide to which stains are added (Gram's stain), then examined under a microscope for bacteria.
• Imaging. X-rays and computerized tomography (CT) scans of the head, chest or sinuses may reveal swelling or inflammation. These tests can also help your doctor look for infection in other areas of the body that may be associated with meningitis.
• Spinal tap (lumbar puncture). The definitive diagnosis of meningitis is often made by analyzing a sample of your cerebrospinal fluid (CSF), which is collected during a procedure known as a spinal tap. In people with meningitis, the CSF fluid often shows a low sugar (glucose) level along with an increased white blood cell count and increased protein. CSF analysis may also help your doctor identify the exact bacterium that's causing the illness. It can take up to a week to get these test results, If your doctor suspects meningitis, he or she may order a DNA-based test known as a polymerase chain reaction (PCR) amplification to check for the presence of viral causes of meningitis. This may provide results about your meningitis in as little as four hours and help to determine proper treatment.

If you have chronic meningitis caused by cancer or an inflammatory illness, you may need additional tests.