Meningitis is an inflammation of a thin tissue called membranes (meninges) surrounding your brain and spinal cord, usually due to infection. A bacterial or viral infection of the fluid surrounding the brain and spinal cord usually causes the swelling. However, injuries, cancer, certain drugs, and other types of infections also can cause meningitis.
Most cases of meningitis in the United States are caused by a viral infection, but bacterial, parasitic and fungal infections are other causes. Meningitis is generally rare but can be deadly.
Anyone can get meningitis, but it is more common in people with weak immune systems. Meningitis can get serious very quickly. If you suspect that someone has meningitis, the first choice is to seek immediate medical care. Early treatment of bacterial meningitis can prevent serious complications.
Possible signs and symptoms in anyone older than the age of 2 include:
- Stiff neck that sometimes makes it hard to touch your chin to your chest
- Headache, which can be severe
- High fever
- Nausea or vomiting
- Discomfort from bright lights
Sometimes these symptoms follow a flu-like illness, ear infection, or sinus infection.
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.
There are several types of meningitis.
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.
Acute bacterial meningitis is the most common form of meningitis. Approximately 80% of all cases are acute bacterial meningitis. Bacterial meningitis can be life threatening. The infection can cause the tissues around the brain to swell. This in turn interferes with blood flow and can result in paralysis or even stroke.
Common strains of bacteria that can cause acute bacterial meiningitis include:
- Streptococcus pneumoniae (pneumococcus) – the one that cause pneumonia in infants, young children and adults, vaccination is available
- Neisseria meningitidis (meningococcus) – this one is highly contagious and affects mainly teenagers and young adults, and causes local epidemics in college dormitories, boarding schools and military bases. Vaccination is also available.
- Haemophilus influenzae (haemophilus) – this one caused many cases of meningitis in children, but there’s improvement since the introduction of vaccination.
- Listeria monocytogenes (listeria) – these bacteria can be found in unpasteurized cheeses, hot dogs and lunchmeats. 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 often less severe than bacterial meningitis, and people in mild cases can get better on their own (without treatment). You can get it when a virus enters the body through the nose or mouth and travels to the brain.
Babies younger than 1 month old and people with weakened immune systems are more likely to have severe illness from viral meningitis.
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.
Vaccination is available for some strains of viruses.
Fungal meningitis is relatively uncommon and causes chronic meningitis. It may mimic acute bacterial meningitis. Fungal meningitis isn’t contagious from person to person. The most common cause of fungal meningitis for people with weak immune systems is Cryptococcus. This disease is one of the most common causes of adult meningitis in Africa.
Subacute or chronic meningitis
Subacute or chronic meningitis is usually caused by an infection.
Many microorganisms can cause subacute or chronic meningitis. Among the
most important microorganisms are
- Bacteria that cause tuberculosis (Mycobacterium tuberculosis)
- Bacteria that cause Lyme disease (Borrelia burgdorferi)
- Fungi, including Cryptococcus neoformans, Cryptococcus gattii, Coccidioides immitis, Histoplasma capsulatum, and Blastomyces
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.
Your family doctor or pediatrician can diagnose meningitis by checking for signs of infection around the head, ears, throat and the skin along the spine, and diagnostic tests.
Blood cultures are procedures done to detect an infection in the blood and identify the cause. Multiple blood samples are usually collected for testing and from different veins to increase the likelihood of detecting the bacteria or fungi that may be present in small numbers and/or may enter the blood intermittently.
Blood cultures are incubated for several days before being reported as negative. Some types of bacteria and fungi grow more slowly than others and/or may take longer to detect if initially present in low numbers.
When a blood culture is positive, the specific microbe causing the infection is identified and susceptibility testing is performed to inform the healthcare practitioner which antibiotics are most likely to be effective for treatment.
Cerebrospinal fluid (CSF)
Cerebrospinal fluid (CSF) is a clear, colorless liquid found in your brain and spinal cord. Your CSF analysis results may indicate that you have an infection, an autoimmune disorder, such as multiple sclerosis, or another disease of the brain or spinal cord.
A procalcitonin test measures the level of procalcitonin in your blood. A high level could be a sign of a serious bacterial infection. This is done as a blood test.
A head ultrasound is a safe and painless test that uses sound waves to make images of the brain. The image can show the swelling.
CT & MRI
Computerized tomography (CT) or magnetic resonance imaging (MRI) scans of the head may show swelling or inflammation. X-rays or CT scans of the chest or sinuses also may show infection in other areas that may be associated with meningitis.
The treatment depends on the type of meningitis you or your child has.
Antibiotics are used in treating bacterial meningitis. Sometimes a combination of antibiotics is necessary. For acute meningitis, immediate intravenous antibiotics are must and sometimes with corticosteroids, this will reduce the risk of complication and ensure recovery.
Treatment to mild viral meningitis include bed rest, hydration, OTC pain medicine. Corticosteroids may be used to reduce swelling in the brain, and an anticonvulsant medication may be used to control seizures. If a herpes virus caused your meningitis, an antiviral medication is available.
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.
Vaccinations are the best prevention.
- Hib vaccine
- Meningococcal ACWY Vaccine
- Pneumococcal Conjugate Vaccine (PCV13)
- Pneumococcal Polysaccharide Vaccine (PPSV23)
People with cochlear implants are more likely to get bacterial meningitis than people without cochlear implants. In addition, some people who are candidates for cochlear implants have anatomic factors (facial and cranial abnormalities including of the temporal bone and cochlea) that may increase their risk for meningitis.
Due to their increased risk, CDC recommends pneumococcal vaccination for people who have or are candidates for cochlear implants.
Others that can help with prevention are:
- Wash your hands thoroughly and frequently.
- Practice good hygiene. Don’t share drinks, foods, straws, eating utensils, lip balms or toothbrushes with anyone else.
- Stay healthy. Get enough rest, exercise regularly, eat a healthy diet with plenty of fresh fruits, vegetables and whole grains.
- Cover your mouth. When you need to cough or sneeze, be sure to cover your mouth and nose.
- If you’re pregnant, take care with food. Reduce your risk of listeriosis by cooking meat, including hot dogs and deli meat, to 165 F (74 C). Avoid cheeses made from unpasteurized milk. Choose cheeses that are clearly labeled as being made with pasteurized milk.
Drink plenty of fluids，rest as much as possible, take acetaminophen (Tylenol, others) to reduce your fever and body aches, don’t go to public place until you completely recover.