Health-Related Issues -- Meningitis
What is bacterial meningitis?
Meningitis is an infection of the fluid of a person's spinal cord and the fluid that surrounds the brain. People sometimes refer to it as spinal meningitis. Meningitis is usually caused by a viral or bacterial infection. Knowing whether meningitis is caused by a virus or bacterium is important because the severity of illness and the treatment differ. Viral meningitis is generally less severe and resolves without specific treatment, while bacterial meningitis can be quite severe and may result in brain damage, hearing loss, or learning disability. For bacterial meningitis, it is also important to know which type of bacteria is causing the meningitis because 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 meningitidis are the leading causes of bacterial meningitis.
What are the signs and symptoms of bacterial meningitis?
High fever, headache, and stiff neck are common symptoms of meningitis in anyone over the age of 2 years. These symptoms can develop over several hours, or they may take 1 to 2 days. Other symptoms may include nausea, vomiting, discomfort looking into bright lights, confusion, and sleepiness. In newborns and small infants, the classic symptoms of fever, headache, and neck stiffness may be absent or difficult to detect, and the infant may only appear slow or inactive, or be irritable, have vomiting, or be feeding poorly. As the disease progresses, patients of any age may have seizures.
How is bacterial meningitis diagnosed?
Early diagnosis and treatment are very important. If symptoms occur, the patient should see a doctor immediately. The diagnosis is usually made by growing bacteria from a sample of spinal fluid. The spinal fluid is obtained by performing a spinal tap, in which a needle is inserted into an area in the lower back where fluid in the spinal canal is readily accessible. Identification of the type of bacteria responsible is important for selection of correct antibiotics.
Can bacterial meningitis be treated?
Bacterial meningitis can be treated with a number of effective antibiotics. It is important, however, that treatment be started early in the course of the disease. Appropriate antibiotic treatment of most common types of bacterial meningitis should reduce the risk of dying from meningitis to below 15%, although the risk is higher among the elderly.
Is bacterial meningitis contagious?
Yes, some forms are bacterial meningitis are contagious. The bacteria are spread through the exchange of respiratory and throat secretions (i.e., coughing, kissing). Fortunately, none of the bacteria that cause meningitis are as contagious as things like the common cold or the flu, and they are not spread by casual contact or by simply breathing the air where a person with meningitis has been.
However, sometimes the bacteria that cause meningitis have spread to other people who have had close or prolonged contact with a patient with meningitis caused by Neisseria meningitidis (also called meningococcal meningitis) or Hib. People in the same household or day-care center, or anyone with direct contact with a patient's oral secretions (such as a boyfriend or girlfriend) would be considered at increased risk of acquiring the infection. People who qualify as close contacts of a person with meningitis caused by N. meningitidis should receive antibiotics to prevent them from getting the disease. Antibiotics for contacts of a person with Hib meningitis disease are no longer recommended if all contacts 4 years of age or younger are fully vaccinated against Hib disease.
Are there vaccines against bacterial meningitis?
Yes, there are vaccines against Hib and against some strains of N. meningitidis and many types of Streptococcus pneumoniae. The vaccines against Hib are very safe and highly effective. There is also a vaccine that protects against four strains of N. meningitidis, but it is not routinely used in the United States. The vaccine against N. meningitidis is sometimes used to control outbreaks of some types of meningococcal meningitis in the United States. Meningitis cases should be reported to state or local health departments to assure follow-up of close contacts and recognize outbreaks. Although large epidemics of meningococcal meningitis do not occur in the United States, some countries experience large, periodic epidemics. Overseas travelers should check to see if meningococcal vaccine is recommended for their destination. Travelers should receive the vaccine at least 1 week before departure, if possible. Information can be obtained by calling the Centers for Disease Control and Prevention at (404)-332-4565.
A vaccine to prevent meningitis due to S. pneumoniae (also called pneumococcal meningitis) can also prevent other forms of infection due to S. pneumoniae. The pneumococcal vaccine is not effective in children under 2 years of age but is recommended for all persons over 65 years of age and younger persons with certain chronic medical problems.
Viral (Aseptic) Meningitis
What is viral meningitis?
Meningitis is an illness in which there is inflammation of the tissues that cover the brain and spinal cord. Viral or aseptic meningitis, which is the most common type, is caused by an infection with one of several types of viruses. Meningitis can also be caused by infections with several types of bacteria or fungi.
What are the symptoms of viral meningitis?
The symptoms of meningitis may not be the same for every person. The more common symptoms are fever, severe headache, stiff neck, bright lights hurt the eyes, drowsiness or confusion, and nausea and vomiting. In babies, the symptoms are more difficult to identify. They may include fever, fretfulness or irritability, difficulty in awakening the baby, or the baby refuses to eat.
Is viral meningitis a serious disease?
Viral (aseptic) meningitis is serious but rarely fatal in persons with normal immune systems. Usually, the symptoms last from 7 to 10 days and the person recovers completely. Bacterial meningitis, on the other hand, can be very serious and result in disability or death if not treated promptly. Often, the symptoms of viral meningitis and bacterial meningitis are the same. For this reason, if you think you or your child has meningitis, see your doctor as soon as possible.
What causes viral meningitis?
Many different viruses can cause meningitis. About 90% of cases of viral meningitis are caused by members of a group of viruses known as enteroviruses, such as coxsackieviruses and echoviruses. Herpesviruses and the mumps virus can also cause aseptic meningitis.
How is viral meningitis diagnosed?
Viral meningitis is usually diagnosed by laboratory tests of spinal fluid obtained with a spinal tap. It can also be diagnosed by tests that identify the virus in specimens collected from the patient, but these tests are not usually done.
How is viral meningitis treated?
No specific treatment for viral meningitis exists at this time. Most patients recover completely on their own, and doctors often will recommend bed rest, plenty of fluids, and medicine to relieve fever and headache.
Can I get viral meningitis if I’m around someone who has it?
The viruses that cause viral meningitis are contagious. Enteroviruses, for example, are very common during the summer and early fall, and many people are exposed to them. However, most infected persons either have no symptoms or develop only a cold or rash with low-grade fever. Typically, fewer than 1 of every 1000 persons infected actually develop meningitis. Therefore, if you are around someone who has viral meningitis, you have a moderate chance of becoming infected, but a very small chance of developing meningitis.
How is the virus spread?
Enteroviruses, the most common cause of viral meningitis, are most often spread through direct contact with respiratory secretions (e.g., saliva, sputum, or nasal mucus). This usually happens by shaking hands with an infected person or touching something they have handled, and then rubbing your own nose, mouth or eyes. The virus can also be found in the stool of persons who are infected. The incubation period is usually between 3 and 7 days from the time you are infected until you develop symptoms. You can usually spread the virus to someone else beginning about 3 days after you are infected until about 10 days after you develop symptoms.
How can I reduce my chances of becoming infected?
Because most persons who are infected with enteroviruses do not become sick, it can be difficult to prevent the spread of the virus. If you are in contact with someone who has viral meningitis, however, the most effective method of prevention is to wash your hands thoroughly and often. In institutional settings such as child care centers, washing objects and surfaces with a dilute bleach solution (made by mixing 1 capful of household bleach with 1 gallon water) can be a very effective way to inactivate the virus.