What is Meningitis?
Meningitis is the inflammation of the meninges, the membranes that surround the brain and the spinal cord. The inflammation is most commonly caused by an infection and can result in swelling and tissue damage.
Meningitis can be caused by viral infections, bacterial infections, fungal infections, parasitic infections, and some other noninfectious conditions. Most cases of meningitis are caused by viruses and are not usually life-threatening. Bacterial meningitis, however, can be much more serious and, if left untreated, may be fatal in a matter of days or even hours.
Viral meningitis is the most common form of the disease in the United States. This form of meningitis usually produces relatively mild symptoms, and in most cases, it resolves on its own without treatment. Viruses that may cause the disease include herpes simplex virus, HIV, mumps, and West Nile virus.
Bacterial meningitis is a severe form of the disease that occurs when bacteria enter the body and travel through the bloodstream to the brain or the spinal cord. When these infections go untreated, they can worsen very quickly and cause life-threatening complications. Bacteria that commonly cause meningitis include streptococcus pneumoniae, neisseria meningitidis, haemophilus influenzae, and listeria monocytogenes.
Other Forms of Meningitis
Fungal meningitis is uncommon, but like bacterial meningitis, it can produce life-threatening complications. Some microscopic parasitic organisms can also cause meningitis. Meningitis may also develop due to inflammatory diseases such as Lyme disease, some types of cancer, allergies, drug reactions, or reactions to chemical exposure.
Symptoms of Meningitis
Symptoms of meningitis include:
- High fever
- Severe, unexplained headache
- Neck stiffness
- Nausea and/or vomiting
- Light sensitivity
- Lethargy or sleepiness
- Problems with concentration or confusion
- Problems with walking
- Loss of appetite
Symptoms of meningitis in infants can be more challenging to spot. They include:
- Inconsolable crying
- High fever
- Excessive sleepiness
- Loss of appetite
- Neck or body stiffness
- A bulge in the soft spot on top of the head
What Causes Meningitis?
The bacteria and viruses that cause meningitis usually enter the body elsewhere and travel to the meninges through the bloodstream. Many of these organisms cause other types of problems, such as respiratory diseases, in other parts of the body, but they become especially dangerous when they infect the tissues around the central nervous system.
Many of the agents that cause meningitis are infectious, meaning that they can be transferred from person to person through close contact. Some forms of the disease are especially problematic where people live in close proximity, such as in college dorms or schools. They may be transmitted when people share eating utensils, are exposed to infected peoples’ coughs or sneezes, or are in close contact (e.g., kissing).
Is Meningitis Hereditary?
For bacterial or viral meningitis to occur, the patient has to come into contact with the bacteria or virus that causes it. But merely being exposed to the infectious agents doesn’t mean that a person will develop meningitis. Some people are exposed to the bacterial or viral culprits with no consequences, while others develop a severe form of the disease. Researchers have looked into the possibility that inherited factors might make some people more susceptible to severe meningitis.
A 2010 study conducted at Imperial College London compared the genes of 1,500 people who had contracted meningitis caused by meningococcal bacteria to thousands of healthy people’s genes. The researchers found several different genetic characteristics that were common in meningitis patients. These characteristics were associated with the ability to fight bacterial infections, suggesting that inherited genetic traits might put an individual at higher risk of developing meningitis.
How is Meningitis Detected?
Meningitis can quickly develop into a life-threatening illness unless the infection is treated promptly. The longer treatment is delayed, the more likely it is that the patient could die or suffer permanent, severe complications. It’s essential to seek medical care at the first signs of the illness.
See a doctor if you or a loved one shows symptoms such as:
- High fever
- Severe, unexplained headache that won’t go away
- Stiff neck
- Nausea or vomiting
- Confusion or disorientation
It’s also important to see a doctor if you, your child, or a loved one has been in close contact with someone who has been diagnosed with meningitis. Precautionary antibiotic treatment may be recommended to prevent an infection.
How is Meningitis Diagnosed?
When a doctor suspects meningitis, they will conduct a physical exam to look for symptoms of the disease. The doctor will probably also ask questions to determine if the patient is likely to have been exposed to an infectious agent that could cause meningitis.
If the symptoms and medical history indicate that meningitis is possible, the doctor may order further tests to confirm the diagnosis. These tests may include:
- Blood tests. These tests will look for evidence that a meningitis-causing organism (especially bacteria) is present in the patient’s blood.
- Imaging tests. These tests–which could include x-rays, computerized tomography (CT) scans, or magnetic resonance imaging (MRI)–will look for signs of inflammation or swelling in or around the head.
- Spinal tap/lumbar puncture. This test examines the fluid of the spinal column and is the most definitive test for meningitis. The test measures the fluid’s levels of sugar, protein, and white blood cells, and it may also indicate the type of bacteria present.
PLEASE CONSULT A PHYSICIAN FOR MORE INFORMATION.
How is Meningitis Treated?
Treatment of bacterial meningitis involves administering intravenous antibiotics to combat the bacterial infection. Sometimes a combination of multiple antibiotics may be prescribed. Corticosteroids may also be used to control swelling and decrease the risk of permanent tissue damage.
Viral meningitis doesn’t respond to antibiotics, but this form of the disease typically resolves itself within a few weeks. Recommended treatment usually includes plenty of rest and fluids, as well as over-the-counter medications to treat any pain or inflammation.
Treatments for the other types of meningitis are focused on controlling the underlying cause of the inflammation. The treatments may include antibiotics, antivirals, or corticosteroids, depending on the cause.
How Does Meningitis Progress?
Even if it’s not fatal, untreated bacterial meningitis can cause permanent damage to the brain and central nervous system. This damage to sensitive nervous-system tissue can result in life-long neurological complications, including:
- Memory problems
- Learning disabilities
- Motor problems
- Hearing loss
- Vision problems
- Kidney problems
How is Meningitis Prevented?
Meningitis can often be prevented by stopping the means of the disease’s transmission and by taking steps to help your body’s resistance to infection. Effective preventive measures include:
- Practice good hygiene. Wash your hands often, and don’t share food, drinks, eating utensils, toothbrushes, or lip balm with other people. Cover your nose and mouth when you cough or sneeze.
- Get immunized, and immunize your children. Many types of bacterial infections can be prevented with common vaccines. Some of these vaccines, such as the Hib and PVC13 vaccines, are part of the standard recommended immunization schedule in the United States. Other vaccines, such as PPSV23 and the meningococcal conjugate vaccine, may be recommended for patients at higher risk for meningitis.
- Boost your immune system. Eat a balanced diet, get plenty of rest, and exercise regularly.
- Practice good food safety. Some meningitis-causing bacteria are transmitted through contaminated food. Cook all meat thoroughly, and avoid cheeses made with unpasteurized milk, especially if you’re pregnant.
Meningitis Caregiver Tips
Children are especially susceptible to meningitis, so parents need to educate themselves about the disease.
- Know the symptoms of meningitis. Learn the early warning signs of meningitis, and be prepared to seek medical help as soon as you see them. Prompt treatment is vital in the case of bacterial meningitis.
- Vaccinate your child. The most common causes of bacterial meningitis can be prevented by following the immunization schedule recommended by your doctor.
- Teach your children good hygiene habits. Ensure they know the importance of washing their hands often, and warn them not to share eating utensils and similar items with their friends. Meningitis can also be a problem in college dorms, where lots of young people live in close quarters. Be sure your college-age children know that the hygiene guidelines are vital for them to follow, too.
Meningitis Brain Science
One active area of meningitis research concerns the way infection-causing bacteria enter the central nervous system. Usually, the blood-brain barrier system prevents harmful substances and organisms from entering the brain via the blood. Somehow, though, meningitis-causing bacteria manage to get through the barrier and affect the meninges. Researchers have determined that some bacteria produce sticky proteins that help them penetrate the barrier, but exactly where and how the bacteria get into the central nervous system is still unclear.
Scientists are also trying to understand better how bacteria produce inflammation and how the bacteria’s toxic action causes permanent damage to nerve cells.
Title: Etiology, Pathogenesis, and Natural History of Idiopathic CD4+ Lymphocytopenia
Principal investigator: Irini Sereti, MD
National Institute of Allergy and Infectious Diseases
Idiopathic CD4+ lymphocytopenia (ICL) is a disorder characterized by decreased numbers of circulating CD4+ T lymphocytes in the absence of known causes of CD4+ lymphocytopenia. ICL is defined as an absolute CD4+ T cell count of fewer than 300 cells/microL in a patient with no human immunodeficiency virus infection or known immunodeficiency syndrome. The causes and frequency of the disorder remain unknown. The condition is typically diagnosed when patients present with a serious infection. In this natural history protocol, we will evaluate patients with CD4+ T cell counts below 300 cells/microL. We propose to follow 200 ICL patients for a minimum of 4 and a maximum of 20 years, with a particular focus on the association between ICL and autoimmune disease. In addition to the ICL patients, we will enroll blood relatives and household contacts to better understand the syndrome’s pathogenesis and etiologies. We will collect blood and other tissues for immunologic, rheumatologic, and genetic testing in an effort to identify and understand the underlying defects that cause ICL and follow its course in a cohort of patients who will receive the best standard therapy for opportunistic infections.
Title: Immunogenicity and Safety of a Quadrivalent Meningococcal Conjugate Vaccine When Administered Concomitantly With Routine Pediatric Vaccines in Healthy Infants and Toddlers in the US
Principal investigator: Medical Director, Sanofi Pasteur
Healthy infants will be enrolled and randomized to receive either 4 doses of MenACYW conjugate vaccine or 4 doses of the licensed control vaccine, MENVEO®. All participants will receive routine vaccines as per the Advisory Committee on Immunization Practices (ACIP) recommendations.
All participants will be assessed for immunogenicity at baseline (pre-vaccination), and after completing the infant schedule and the second year of life vaccination schedule.
Safety will be assessed throughout the study period, and includes solicited injection site and systemic reactions as well as unsolicited adverse events after each vaccine injection, and serious adverse events occurring throughout the trial.
The purpose of this study is to compare the immunogenicity and describe the safety of MenACYW conjugate vaccine and MENVEO® when both are administered concomitantly with routine pediatric vaccines to healthy infants and toddlers in the US.
To demonstrate the non-inferiority of the immune response after a 4-dose series of MenACYW conjugate vaccine compared to a 4-dose series of MENVEO when given concomitantly with routine pediatric vaccines to infants and toddlers 6 weeks to 15 months of age.
To demonstrate the non-inferiority of the immune response after 3 doses of MenACYW conjugate vaccine compared to 3 doses of MENVEO when given concomitantly with routine pediatric vaccines to infants at 2, 4, and 6 months of age.
To demonstrate the non-inferiority of the immune responses of the routine pediatric vaccines administered concomitantly with MenACYW conjugate vaccine as compared with MENVEO to infants and toddlers 6 weeks to 18 months of age.
To assess the antibody responses against meningococcal serogroups A, C, Y, and W after the administration of the 4th dose of MenACYW conjugate vaccine as compared with MENVEO® when both are given concomitantly with routine pediatric vaccines at 12 months of age.
To assess the persistence of bactericidal antibodies at 12 months of age (prior to the 4th dose) in participants who previously received 3 doses of MenACYW conjugate vaccine or MENVEO® in infancy concomitantly with routine pediatric vaccines at 2, 4, and 6 months of age.
To describe the safety profile of MenACYW conjugate vaccine and MENVEO when administered concomitantly with routine pediatric vaccines in healthy infants and toddlers.
Title: Next Generation Sequencing Detection of Lyme Disease
Principal investigator: Christy A Beneri
Stony Brook University Clinical Research Center
Next Generation Sequencing is capable of sequencing millions of tiny strands of DNA from a single blood sample, potentially improving its sensitivity compared to PCR testing, which only detects predetermined larger strands of DNA. We will test the ability of NGS to detect Borrelia burgdorferi DNA in the blood of pediatric patients with Lyme disease. We will conduct an observational study of NGS testing on pediatric patients at all stages of Lyme disease. Study involvement will require a single study visit for clinical data collection and blood draw. We will enroll patients at all phases of suspected Lyme disease, collect clinically relevant information, and test for Lyme disease using Next Generation Sequencing and standard Lyme serologic testing. If the patient has multiple erythema migrans, Lyme meningitis, facial nerve palsy, arthritis, or carditis, a B. burgdorferi serum PCR will also be sent. Enrollment and Next Generation Sequencing blood draw will occur before or up to 24 hours after the first dose of antibiotics is administered. We will also study the impact of antibiotics on NGS testing by running the test 6-24 hours after antibiotics are started among a small subset of patients with a multiple erythema migrans rash. Collected data will be analyzed with basic descriptive statistics.