Enteroviral meningitis

Related Terms

Acquired immunodeficiency syndrome, adrenal gland, AIDS, bacterial meningitis, cancer, cerebro-spinal fluid, chronic meningitis, cochlear implant, computerized tomography, cortisol, CSF, CT, enteroviral meningitis, Escherichia coli, fungal meningitis, Haemophilus influenzae type b vaccine, Haemophilus influenzae, herpes viruses, Hib vaccine, HIV, human immunodeficiency virus, kidney dialysis, Listeria monocytogenes, lumbar puncture, Lyme disease, MCV4, meninges, meningococcal conjugate vaccine, meningococcal disease, MMR, mumps, Neisseria meningititis, opisthotonos, PCR, PCV, pneumococcal conjugate vaccine, pneumococcal polysaccharide vaccine, polymerase chain reaction, PPV, sepsis, spinal meningitis, spinal tap, Streptococcus pneumoniae, syphilis, TB, throat culture, tuberculosis, ultrasound, upper respiratory infections, viral meningitis, white blood cells, X-rays.

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.

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.

Integrative therapies

Unclear or conflicting scientific evidence:
Alizarin: Limited available evidence suggests that alizarin may be of benefit in the treatment of viral infections. Additional research is needed in this area.
Avoid if allergic or hypersensitive to alizarin or any plants in the Rubiaceae family. Alizarin may be toxic and should not be handled for long periods of time, rubbed in the eyes, or eaten. Avoid if pregnant or breastfeeding.
Ayurveda: Ayurveda is a form of natural medicine that originated in ancient India more than 5,000 years ago. It includes an integrated system of techniques that uses diet, herbs, exercise, meditation, yoga, and massage or bodywork to achieve optimal health on all levels. Early evidence suggests that the aqueous extract of O. sanctum leaves may benefit patients with viral encephalitis. However, human studies are needed to evaluate this approach.
Ayurvedic herbs can interact with other herbs, foods, and drugs. A qualified healthcare professional should be consulted before taking. Ayurvedic herbs should be used cautiously because they are potent and some constituents can be potentially toxic if taken in large amounts or for a long time. Some herbs imported from India have been reported to contain high levels of toxic metals. Avoid Ayurveda with traumatic injuries, acute pain, advanced disease stages, and medical conditions that require surgery.
Bitter orange: Limited available human study found promising results using the oil of bitter orange for treatment of fungal infections. However, due to methodological weakness of this research, further evidence is needed to confirm these results.
Avoid if allergic or hypersensitive to bitter orange or any members of the Rutaceae family. Avoid with heart disease, narrow-angel glaucoma, intestinal colic, or long QT interval syndrome. Avoid if taking anti-adrenergic agents, beta-blockers, QT-interval prolonging drugs, monoamine oxidase inhibitors (MAOIs), stimulants, or honey. Use cautiously with headache, hyperthyroidism (overactive thyroid), or if fair-skinned. Avoid if pregnant or breastfeeding.
Blessed thistle: Human research of blessed thistle as a treatment for viral infections or bacterial infections is currently lacking. Laboratory studies report that blessed thistle (and chemicals contained in blessed thistle, such as cnicin and polyacetylene) may have activity against several types of bacterial infections and no effects on some types. Early studies report no activity of blessed thistle against herpes viruses, influenza, or poliovirus. Further evidence is necessary in this area before a firm conclusion can be drawn.
Blessed thistle is generally considered to be safe when taken by mouth in recommended doses for short periods of time, with few reported side effects such as birth defects, bleeding, breathing problems, bruising, cancer of the nose or throat, increased production of stomach acid, itching, kidney disease, liver toxicity, skin rash, stomach discomfort, stomach ulcers, and vomiting. Allergic reactions to blessed thistle including rash may occur, as well as cross-sensitivity to mugwort and Echinacea. Cross-reactivity may also occur with bitter weed, blanket flower, Chrysanthemum, coltsfoot, daisy, dandelion, dwarf sunflower, goldenrod, marigold, prairie sage, ragweed or other plants in the Asteraceae/Compositae family. Avoid if pregnant or breastfeeding.
Cranberry: Limited laboratory research has examined the antiviral, antifungal and antibacterial activity of cranberry. Further research is warranted in this area.
Avoid if allergic to cranberries, blueberries, or other plants of the Vaccinium species. Sweetened cranberry juice may affect blood sugar levels. Use cautiously with a history of kidney stones. Pregnant and breastfeeding women should avoid cranberry in higher amounts than what is typically found in foods.
DMSO: Dimethyl sulfoxide (DMSO) is a sulfur-containing organic compound that occurs naturally in vegetables, fruits, grains, and animal products. Early research suggests that DMSO may help treat increased intracranial pressure. However, most research is vague with conflicting results and the risks may be greater than potential benefits.
Avoid if allergic or hypersensitive to DMSO. Use caution with urinary tract cancer or liver and kidney dysfunction. Avoid if pregnant or breastfeeding.
Garlic: Garlic is used both medicinally and as a food spice. Preliminary research suggests that oral plus intravenous garlic may help manage symptoms of cryptococcal meningitis, a fungal infection that commonly occurs in HIV patients. Further research is needed before recommending for or against the use of garlic in the treatment of this potentially serious condition, for which other treatments are available.
Use cautiously as garlic can cause severe burns and rash when applied to the skin of sensitive individuals. Avoid if allergic or hypersensitive to garlic or other members of the Lilaceae(lily) family (e.g. hyacinth, tulip, onion, leek, or chive). Avoid with a history of bleeding problems, asthma, diabetes, low blood pressure, or thyroid disorders. Stop using supplemental garlic two weeks before and immediately after dental/surgical/diagnostic procedures with bleeding risks. Avoid in supplemental doses if pregnant or breastfeeding.
Ginseng: Preliminary study of Xuesaitong injection (XSTI, a preparation of Panax notoginseng) reports that it may help to decrease intracranial pressure and benefit coma patients. Further study is needed to confirm these results.
Avoid with known allergy to plants in the Araliaceae family. There has been a report of a serious life-threatening skin reaction, possibly caused by contaminants in ginseng formulations.
Pomegranate: In clinical study, an extract of pomegranate was shown to be as effective as a commonly used oral gel when used topically to treat candidiasis associated with denture stomatitis (mouth sores). Additional study is needed to confirm pomegranate's antifungal effects.
Avoid if allergic or hypersensitive to pomegranate. Avoid with diarrhea or high or low blood pressure. Avoid taking pomegranate fruit husk with oil or fats to treat parasites. Pomegranate root/stem bark should only be used under the supervision of a qualified healthcare professional. Use cautiously with liver damage or liver disease. Pomegranate supplementation may be unsafe during pregnancy when taken by mouth. The bark, root, and fruit rind may cause menstruation or uterine contractions. Avoid if breastfeeding due to a lack of scientific data.
Probiotics: There is limited evidence that probiotic supplementation may reduce the presence of bacterial infections. More studies are needed to determine the effectiveness of probiotics for this indication.
Probiotics are generally considered to be safe and well-tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose intolerant. Caution is advised when using probiotics in neonates born prematurely or with immune deficiency.
Propolis: Propolis is a natural resin created by bees to make their hives. Propolis is made from the buds of conifer and poplar trees and combined with beeswax and other bee secretions. Animal and laboratory studies suggest that propolis may be a beneficial treatment for various types of bacterial and fungal infections. Additional research is needed to confirm these findings.
Avoid if allergic or hypersensitive to propolis, black poplar (Populas nigra), poplar bud, bee stings, bee products, honey, or Balsam of Peru. Severe allergic reactions have been reported. There has been one report of kidney failure with the ingestion of propolis that improved upon discontinuing therapy and deteriorated with re-exposure. Avoid if pregnant or breastfeeding because of the high alcohol content in some products.
Riboflavin: Riboflavin (vitamin B2) is a water-soluble vitamin, which is involved in vital metabolic processes in the body, and is necessary for normal cell function, growth, and energy production. Small amounts of riboflavin are present in most animal and plant tissues. Although the exact pathogenesis of ethylmalonic encephalopathy is unknown, some research suggests that riboflavin may lead to slight improvements in motor function, cognitive behavior, and diarrhea in this disorder.
Avoid if allergic or hypersensitive to riboflavin. Since the amount of riboflavin a human can absorb is limited, riboflavin is generally considered safe. Riboflavin is generally regarded as safe during pregnancy and breastfeeding. The U.S. Recommended Daily Allowance (RDA) for riboflavin in pregnant women is higher than for non-pregnant women, and is 1.4 milligrams daily (1.6 milligrams for breastfeeding women).
Seaweed, kelp, bladderwrack: Bladderwrack (Fucus vesiculosus) is a brown seaweed found along the northern coasts of the Atlantic and Pacific oceans and North and Baltic seas. Another seaweed that grows alongside bladderwrack is Ascophyllum nodosum, andit is often combined with bladderwrack in kelp preparations. Laboratory research suggests that bladderwrack may have antifungal and antibacterial activity. However, reliable human studies to support this use are currently lacking in the available literature.
Avoid if allergic or hypersensitive to Fucus vesiculosus or iodine. Avoid with a history of thyroid disease, bleeding, acne, kidney disease, blood clots, nerve disorders, high blood pressure, stroke, or diabetes. Avoid if pregnant or breastfeeding.
Selenium: Selenium is a trace mineral found in soil, water, and some foods and is essential in several metabolic pathways. Preliminary research shows that selenium may decrease elevated intracranial pressure symptoms such as headaches, nausea, vomiting, vertigo, unsteady gait, speech disorders, and seizures. More research is needed.
Avoid if allergic or sensitive to products containing selenium. Avoid with a history of nonmelanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.
Sorrel: There is currently not enough evidence on the proposed antiviral and antibacterial effects of sorrel. More research is needed.
Avoid large doses of sorrel because there have been reports of toxicity and death. This may be because of the oxalate found in sorrel. Many sorrel tinctures contain high levels of alcohol and should be avoided when driving or operating heavy machinery. These sorrel formulations may cause nausea or vomiting when taken with the prescription drugs metronidazole (Flagyl?) or disulfiram (Antabuse?). Avoid if pregnant or breastfeeding.
Thymus extract: Thymus extracts for nutritional supplements are usually derived from young calves (bovine). Bovine thymus extracts are found in capsules and tablets as a dietary supplement. Preliminary evidence suggests that thymus extract has no clinical effect in patients with subacute sclerosing panencephalitis. Additional study is needed to confirm the effects of thymus extract on encephalitis.
Avoid if allergic or hypersensitive to thymus extracts. Use bovine thymus extract supplements cautiously due to potential for exposure to the virus that causes "mad cow disease." Avoid use with an organ transplant or other forms of allografts or xenografts. Avoid if receiving immunosuppressive therapy, with thymic tumors, myasthenia gravis (neuromuscular disorder), untreated hypothyroidism, or if taking hormonal therapy. Avoid if pregnant or breastfeeding; thymic extract increases human sperm motility and progression.
Turmeric: Turmeric is a perennial plant native to India and Indonesia, and it is often used as a spice in cooking. Based on early research, turmeric may help treat various viral infections. However, reliable human studies are lacking in this area. Well-designed trials are needed.
Avoid if allergic or hypersensitive to turmeric (curcumin), yellow food colorings, or plants belonging to the Curcuma or Zingiberaceae (ginger) families. Use cautiously with a history of bleeding disorders, immune system deficiencies, liver disease, or gallstones. Use cautiously with blood thinners (e.g. warfarin). Use cautiously if pregnant or breastfeeding.
Fair negative scientific evidence:
Macrobiotic diet: A macrobiotic diet has been advocated to preserve intestinal health. However, it apparently does not reduce the incidence of antibiotic resistant bacteria, nor infections caused by resistant strains in the gastrointestinal tract, compared to a diet with animal products.
Use cautiously with cancer or other medical conditions without expert planning or supplementation. Avoid in children or adolescents without professional guidance or appropriate supplementation. Avoid in pregnant or lactating women due to potential deficiencies, unless properly supplemented.
Probiotics: Bacterial infection translocation, the passage of bacteria from the gut to other areas of the body where they can cause disease, is of special concern in surgery. Limited evidence suggests that supplementation with probiotics may not reduce this problem.
Probiotics are generally considered to be safe and well-tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose intolerant. Caution is advised when using probiotics in neonates born prematurely or with immune deficiency.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

American Academy of Family Physicians. .
American Academy of Pediatrics. .
Joffe AR. Lumbar puncture and brain herniation in acute bacterial meningitis: a review. J Intensive Care Med. 2007;22(4):194-207.
Mehlhorn AJ, Balcer HE, Sucher BJ. Update on prevention of meningococcal disease: focus on tetravalent meningococcal conjugate vaccine. Ann Pharmacother. 2006 Apr;40(4):666-73. Epub 2006 Mar 7.
National Institute of Neurological Disorders and Stroke. .
National Institute of Allergy and Infectious Diseases. .
National Institutes of Health. .
Natural Standard: The Authority on Integrative Medicine. .
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.
van de Beek D, Weisfelt M, de Gans J, Tunkel AR, Wijdicks EF. Drug Insight: adjunctive therapies in adults with bacterial meningitis. Nat Clin Pract Neurol. 2006;2(9):504-16.
Wilder-Smith A. Meningococcal vaccine in travelers. Curr Opin Infect Dis. 2007;20(5):454-60.

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.

Risk factors

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.

Prevention and self-management

Meningitis typically results from contagious infections. Common bacteria or viruses that can cause meningitis can spread through coughing, sneezing, kissing, or sharing eating utensils, a toothbrush, or a cigarette. Individual's are also at increased risk if they live or work with someone who has the disease.
Hygiene: Careful hand washing is important to avoiding exposure to infectious agents. Children should be taught to wash their hands often, especially before they eat and after using the toilet, spending time in a crowded public place, or petting animals.
Haemophilus influenzae type b (Hib) vaccine: Children in the United States routinely receive the Haemophilus influenza type b (Hib) vaccine as part of the recommended schedule of vaccines, starting at about two months of age. The vaccine is also recommended for some adults, including those with sickle cell disease or acquired immunodeficiency syndrome (AIDS).
Pneumococcal conjugate vaccine (PCV7): The pneumococcal conjugate (PCV7) vaccine is also part of the regular immunization schedule for children younger than two years in the United States. In addition, the vaccine is recommended for children between the ages of two and five who are at high risk of pneumococcal disease, including children with chronic heart or lung disease or cancer.
Pneumococcal polysaccharide vaccine (PPV): The pneumococcal polysaccharide vaccine (PPV) is used for older children and adults who need protection from pneumococcal bacteria. The U.S. Centers for Disease Control and Prevention (CDC) recommends the PPV vaccine for all adults older than 65 and younger adults and children with compromised immune systems or chronic illnesses such as heart disease, diabetes, or sickle cell anemia.
Meningococcal conjugate vaccine (MCV4): The meningococcal conjugate vaccine (MCV4) is recommended by the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) to be routinely administered for the following previously unvaccinated groups: children 11-12 years old, adolescents at high school entry (about age 15), and college freshmen living in dormitories.