Meningitis
medical conditions

Meningitis

Explore the available health information, treatment context, and integrative evidence for Meningitis.

Background
  • Meningitis, also called meningococcal disease or spinal meningitis, is inflammation of the thin tissue that surrounds the brain and spinal cord (called the meninges).
  • There are several types of meningitis. The most common is viral meningitis, which is contracted when a virus enters the body through the nose or mouth and travels to the brain. Bacterial meningitis is rare, but can be deadly. Initial symptoms usually resemble a cold. Bacterial meningitis can block blood vessels in the brain and lead to stroke and brain damage. It can also harm other organs. Left untreated, bacterial meningitis can be fatal.
  • For bacterial meningitis, it is also important to know which type of bacteria is causing the meningitis. Antibiotics can prevent some types from spreading and infecting other people. Before the 1990s, Haemophilus influenzae type b (Hib) was the leading cause of bacterial meningitis, but new vaccines being given to all children as part of their routine immunizations have reduced the occurrence of invasive disease due to H. influenzae. Today, Streptococcus pneumoniae and Neisseria meningititis are the leading causes of bacterial meningitis. Determining the bacteria causing meningitis is important in choosing the correct antibiotic treatment.
  • Anyone can get meningitis, but it is more common in individuals whose bodies have trouble fighting off infections and who have poor immune systems, such as those with human immunodeficiency virus (HIV), cancer, the elderly, and the malnourished. Meningitis can progress rapidly.
  • Hallmark symptoms of meningitis include all of the following: a sudden fever; a severe headache; and a stiff neck. Individuals experiencing these symptoms should seek medical care.
  • In the past, the majority of meningitis cases occurred in children younger than five years. Due to the protection offered by current childhood vaccines, most meningitis cases now occur in young people between the ages of 15-24. The elderly also tend to have a higher incidence of meningitis than do young children due to poor immune health.
  • There are nearly 3,000 cases of meningitis every year in the United States. According to the U.S. Centers for Disease Control and Prevention (CDC), between 10-12% of the cases are fatal.
  • Early treatment can help prevent serious problems, including death. Vaccines can prevent some of the bacterial infections that cause meningitis. Parents of adolescents and students living in college dorms should talk to a doctor about the vaccination.
Risk Factors and Causes
  • Bacterial meningitis: Meningitis in newborns is a rare condition that usually results from an infection of the bloodstream (sepsis). The infection is typically caused by bacteria acquired from the birth canal, most commonly group B streptococci, Escherichia coli, and Listeria monocytogenes. Older infants and children usually develop infection through contact with respiratory secretions from infected people. Bacteria that infect older infants and children include Streptococcus pneumoniae and Neisseria meningititis. Haemophilus influenzae type b was the most common cause of meningitis, but widespread vaccination against that organism has now made it a rare cause. Newer, improved vaccines against Streptococcus pneumoniae and Neisseria meningitiis (pneumococcal and meningococcal conjugate vaccines) should also make these organisms rare causes of childhood meningitis.
  • Viral meningitis: Viral meningitis is usually mild and often clears on its own in 10 days or less. A group of common viruses known as enteroviruses, which cause stomach flu, are responsible for about 90% of viral meningitis in the United States.
  • Fungal meningitis: Fungal meningitis is relatively uncommon. Cryptococcal meningitis is a fungal form of the disease caused by Cryptococus neoformans. Cryptococcal meningitis affects individuals with immune deficiencies, such as acquired immunodeficiency syndrome (AIDS). Fungal meningitis can be life-threatening if not treated with an antifungal medication.
  • Chronic meningitis: Chronic (long-term) forms of meningitis occur when slow-growing organisms invade the membranes and fluid surrounding the brain. Although acute meningitis strikes suddenly, chronic meningitis develops over four weeks or more. Nevertheless, the signs and symptoms of chronic meningitis, including headaches, fever, vomiting, and mental cloudiness, are similar to those of acute meningitis. This type of meningitis is rare. Chronic meningitis can be fungal, bacterial, or viral.
  • Other causes: Meningitis can also result from noninfectious causes, such as drug allergies, some types of cancer, and inflammatory diseases such as lupus.
  • Organisms that cause meningitis can be passed from one person to another or passed from rodents and insects to people. However, exposure to an organism that causes meningitis does not mean the individual will get the infection. A mother can pass organisms that cause meningitis to her baby even if the mother does not have symptoms. Stool is another way of transmission. Stool can have enteroviruses or certain types of bacteria in it. Healthcare providers recommend washing hands on a regular basis to help prevent children from getting infected this way. Infected individuals can pass certain bacteria that are normally found in saliva or mucus in their noses and throats through kissing, sexual contact, or contact with infected blood. The human immunodeficiency virus (HIV) also can cause meningitis and can be passed from an infected person to another person through blood or sexual contact, but not through kissing.

  • Rarely, some organisms that cause meningitis can be passed to people from rodents and insects. The most common of these are arboviruses (including the St. Louis encephalitis and West Nile viruses), which are transmitted through dust and food contaminated by the urine of infected mice, hamsters, and rats.
  • Genetics: Some individuals may inherit the tendency to get meningitis. If they come in contact with organisms that can cause the infection, they may be more likely to get infected.
  • Gender: Males get meningitis more often than females. The causes are not known.
  • Age: In general, babies, young children, young adults, and the elderly are at highest risk of getting meningitis.
  • Crowded living conditions: People in camps, schools, and college dormitories are more likely than others to get meningitis caused by organisms that can spread easily from one person to another.
  • Daycare: Children who attend day care centers are more likely than other children to get meningitis caused by organisms that are easily spread through stool or contaminated hands or water.
  • Exposure to insects and rodents: Individuals who live in or visit areas of the world where insects or rodents carry organisms that cause meningitis risk getting the disease.
  • Non-vaccinated individuals: Not getting the mumps (MMR), Haemophilus influenzae type b (Hib), and pneumococcal conjugate (PCV) vaccinations before age two or being an older adult who has not gotten the pneumococcal polysaccharide (PPV) immunization and/or does not have a working spleen (part of the body's immune system), places the individual at greater risk for developing meningitis.
  • Travel: Individuals traveling to the "meningitis belt" in sub-Saharan Africa are at greater risk of developing meningitis and should receive the meningococcal vaccine.
  • Medical conditions: Medical conditions that increase the risk of meningitis include poor overall health. Individuals who are in poor health or have other medical conditions that lower immunity, such as human immunodeficiency virus (HIV) or cancer, may be more likely to get meningitis because their bodies' natural defenses may be weak. Other conditions that may increase the risk of developing meningitis include: having a birth defect of the skull, a head injury, or brain surgery; undergoing treatment with a kidney dialysis machine; having other infections, such as upper respiratory infections, mumps, tuberculosis (TB), syphilis, Lyme disease, and illnesses caused by herpes viruses; and having a cochlear implant for severe hearing loss. A recent study indicates that children with cochlear implants have an increased risk for bacterial meningitis. Viruses, such as the enteroviruses and herpes viruses, and some bacteria can be passed from an infected mother to a baby during birth. Having had meningitis in the past also places individuals at greater risk for developing the condition. Some individuals who have had meningitis are more likely than others to get it again. These include people with birth defects or injuries to their skull and face, impaired immune systems, or unexpected reactions to some medicines.
Signs and Symptoms
  • Early signs: Early signs and symptoms of meningitis are similar to the flu. They may develop over a period of one or two days and typically include: a high fever (over 102 degrees Fahrenheit), a severe headache; vomiting or nausea with headache; and confusion, or difficulty concentrating. In the very young, this may appear as inability to maintain eye contact; seizures; sleepiness or difficulty awakening; stiff neck; sensitivity to light; a lack of interest in drinking and eating; and a skin rash in some cases, such as in viral or meningococcal meningitis.
  • Earlier signs and symptoms that may suggest a serious infection, although not necessarily meningitis, include leg pain, ice-cold hands and feet, and abnormally pale skin tone.
  • Signs in newborns: Newborns and young infants may not have the classic signs and symptoms of headache and stiff neck, as they cannot express themselves appropriately at that age. Instead, they may cry constantly, seem unusually sleepy or irritable, and eat poorly. Sometimes the soft spots on an infant's head may bulge. A very late sign may be a spasm consisting of extreme hyperextension of the body (opisthotonos).
  • If an individual (adult or child) has bacterial meningitis, delaying treatment increases the risk of permanent brain damage. In addition, bacterial meningitis can prove fatal in a matter of days. Medical care should be sought right away if symptoms of meningitis are present.
  • The most common signs and symptoms of enteroviral infections are rash, sore throat, joint aches, and headache. Many older children and adults with enteroviral meningitis have severe headaches. These viruses tend to circulate in late summer and early fall. Viruses associated with mumps, herpes infection, West Nile virus, or other diseases also can cause viral meningitis.
Diagnosis
  • History and physical: Questions about the history of the illness and a physical examinationhelp determine the likelihood of meningitis.During the exam, a doctor may check for signs of infection around the head, ears, throat, and the skin along the spine.
  • Throat culture: A throat culture can find and identify the bacteria causing throat pain, neck pain, and headache, but cannot determine what pathogens may be in the spinal fluid.
  • Lumbar puncture: A lumbar puncture, or spinal tap, is the sampling of the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord. A lumbar puncture is the primary test for meningitis and is important for the critical distinction between a bacterial or viral cause. A small needle is inserted into the lower back under sterile conditions and CSF is withdrawn. There may be some pain involved, depending on the individual. The CSF may show the presence of bacteria, indicating bacterial infection. White blood cells in the CSF may be related to bacterial meningitis, viral meningitis (no bacteria would be seen in this case), or fungal meningitis. The CSF also is cultured to look for growth of organisms in order to identify them.
  • Blood tests may show an increased white blood cell count, indicating infection. Other tests may be suggested by a doctor depending on the individual situation.
  • Polymerase chain reaction analysis: A polymerase chain reaction (PCR) is a DNA-based test that uses amplification to check for the presence of certain causes of meningitis. A polymerase chain reaction test can be used if a doctor suspects meningitis.
  • Imaging: X-rays, ultrasounds, and computerized tomography (CT) scans of the chest, skull, or sinuses may reveal swelling or inflammation. These tests can also help a doctor look for infection in other areas of the body or infections associated with meningitis.
Complications
  • The complications of meningitis can be severe. The longer the individual has the disease without treatment, the greater the risk of seizures and of permanent neurological damage, including hearing loss, blindness, loss of speech, learning disabilities, behavior problems, brain damage, and even paralysis.
  • Non-neurological complications may include kidney failure and adrenal gland failure. The adrenal glands sit above the kidneys and produce a number of important hormones including cortisol, which helps the body deal with stress.
  • Bacterial infections of the central nervous system can be severe and progress quickly. Within a matter of days, the disease can lead to shock and death. Approximately 10-12% of individuals developing meningitis will die.
Treatment
  • Treatment for meningitis depends on the organism causing the infection, the individual's age, the extent of the infection, and the presence of other medical conditions or complications of meningitis.
  • Most individuals with viral meningitis usually start getting better within three days of feeling sick and recover within two weeks. However, it is important to see a healthcare professional if symptoms of meningitis develop so bacterial meningitis can be ruled out, which is more serious. With mild cases of viral meningitis, the individual may only need home treatment, including fluids to prevent dehydration and medicine to control pain and fever. If they do not get better or if symptoms get worse, the individual may need further testing to check for other causes of illness.
  • Bacterial or severe viral meningitis may require treatment in a hospital, including antibiotics, steroids, medications for pain, intravenous (IV, or in the veins) therapy, and oxygen therapy.
  • Antibiotics: These medicines usually are given through a vein (intravenously, or IV) to treat meningitis. Antibiotics used to treat bacterial meningitis include penicillin (PenG®), ampicillin (Omnipen®), ceftriaxone (Rocephin®), and rifampin (Rifadin®). Antifungal drugs may be used to treat fungal meningitis, including fluconazole (Diflucan®).
  • Steroids: Measures to reduce pressure within the brain include steroid (corticosteroid) prescription medications. If meningitis is causing pressure within the brain, corticosteroid medicines such as dexamethasone (Decadron®) may be given to adults or children.
  • Fever reduction: Measures to reduce fever include medicines such as acetaminophen (Tylenol®), fluids, and good room ventilation. If a high fever is present (over 102 degrees Fahrenheit), the individual may also need a device such as a cooling pad placed on the bed.
  • Seizures: Measures to prevent seizures are also used in susceptible individuals. If the individual is prone to seizures, their surroundings will be kept quiet and calm. Medicines such as phenobarbital or dilantin (Phenytoin®) are used to treat seizures.
  • Oxygen therapy: Oxygen may be given if the individual has trouble breathing and needs to increase the amount of oxygen in all parts of the body. Oxygen may be delivered by a hood or tent placed over the body, a face mask placed over the nose and mouth, a nose piece (nasal cannula) held loosely under the nose, or, in severe cases, a tube through the mouth into the trachea (windpipe).
  • Fluids: Individuals may need to drink extra liquids because infections increase the body's need for fluids. Increasing liquids also reduces the possibility of dehydration. Liquids are given into a vein (IV) if the individual has an infection and is vomiting or not able to drink enough. Healthcare professionals control the amount of fluids given because people with meningitis may develop problems if they have too much or not enough fluid.
  • Blood chemistry: Frequent blood tests are done to measure essential body chemicals, such as sodium, potassium, and sugar in the blood. These are measured to determine the health status of the individual.
  • A person who has severe meningitis may need to be treated in the intensive care unit (ICU) of a hospital. Healthcare professionals watch the individual closely and provide care if needed.
References
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    View Abstract
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  5. National Institute of Neurological Disorders and Stroke. .
  6. National Institute of Allergy and Infectious Diseases. .
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  9. Riddell A, Buttery JP, McVernon J, et al. A randomized study comparing the safety and immunogenicity of a conjugate vaccine combination containing meningococcal group C and pneumococcal capsular polysaccharide--CRM197 with a meningococcal group C conjugate vaccine in healthy infants: challenge phase. Vaccine. 2007;25(19):3906-12.
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