What is meningitis?
Many people think of it as infection of the brain. In truth, it's an infection of the fluid and membranes or lining that are around the brain and the spinal cord. The usual types of meningitis that we see in children and adolescents are caused by either bacteria or viruses. In the summer and fall, we see a fair amount of viral meningitis, which, in general, is not as severe and doesn't have as severe complications as bacterial meningitis. The most common type of viral meningitis this time of year is caused by a broad class of viruses called enteroviruses. Different types of bacteria can cause bacterial meningitis, and the top two types are meningococcal meningitis and pneumococcal meningitis.
How do these infections progress to the brain?
The bacteria or viruses are often first on your mucosal membranes, such as those in your nose or throat. They can sometimes then gain entry into the bloodstream and eventually cross into the brain and associated structures, causing meningitis. Less commonly they can more directly extend from severe infections in areas near the brain, such as from sinus or ear infections.
Why are college students at increased risk of meningococcal meningitis?
Long ago it was known that military recruits had as much as 25 times the risk of acquiring meningococcal disease as the general population. It was thought to be due to just being in close quarters. There have been a variety of studies to try to define exactly why college freshman are also at increased risk. It's living, for perhaps the first time, in close proximity with other people of the same age group. Acquiring the infection depends on exposure to the bacteria, which can be in the nose and cause no symptoms, especially in young adults.
There have been some studies in college students that have implicated alcohol consumption, cigarette smoking and a variety of other factors that may affect the immune system. But the predominant risk factor is probably just an increase in exposure risk in that setting.
Are there other risk factors?
Your risk is certainly increased if you have a specific immune deficiency or if you're in a household or a daycare setting, for example, where there's another person that has meningococcal disease. Some bacteria that cause meningitis can be spread through the exchange of throat or respiratory secretions (coughing, kissing). It is generally a good habit not to share eating or drinking utensils and towels with family members or friends with significant infections. Luckily, meningitis is not as contagious as the viruses that cause colds or the flu.
What are the symptoms?
In general, the symptoms of viral meningitis are a headache and stiff neck along with fever. Sometimes there is nausea and vomiting, sleepiness and photosensitivity, meaning light hurts your eyes. For meningococcal disease, the symptoms also include a specific type of rash.
Influenza or other viral infections can certainly mimic some of these symptoms. But a health professional always has to make sure, if someone has a headache, stiff neck and fever, that meningitis is considered as a diagnosis.
How quickly the symptoms develop varies based on the type of meningitis; it ranges anywhere from a few hours to a few days.
How is meningitis diagnosed?
Meningitis would be suspected based on history and clinical exam. Depending on how strongly the physician suspected that diagnosis, it would be confirmed by performing a lumbar puncture, or what's called a "spinal tap."
It's not uncommon to do spinal taps, especially in pediatrics. It sounds scarier than it is: It's putting a needle into the lower back, into the space around the spinal cord away from nerves and other structures, where it is easy to get fluid. Then that fluid is sent to a lab to check for evidence of bacteria or viruses.
Why do some people develop severe infections?
People have not quite understood why some people will have such an overwhelming infection and others not as severe. Some people may have had a minor defect in their immune system, but others who are totally healthy and acquire meningococcal disease will also have the disease progress rapidly.
What can result from severe infections with bacterial meningitis?
Most of these complications are due to the infection having an effect on various parts of the brain or nervous system. With meningococcal disease, there is a 10 to 15 percent mortality rate. And as many as 10 percent of the survivors can have severe complications. I've seen children and adolescents who have had brain damage or developed seizure disorders, or lost fingers or part of the foot due to the presence of the bacteria in the bloodstream. Hearing loss is a common result of any type of meningitis, and learning disabilities can also be a complication.
What would be your advice to someone who is not sure if they have the flu or meningitis?
It is sometimes difficult, especially during the winter season, when we're seeing so much influenza and other viral infections. If you have any question you may have meningitis, you certainly need to contact your healthcare provider. It's especially important for college students to be aware of the symptoms and signs of meningitis and to seek medical attention if they are concerned or have a headache, stiff neck and fever.
How is meningitis treated?
It varies with each type of meningitis. For the usual viral causes, such as enteroviruses, there's really no specific treatment and it's really just supportive care. Antibiotics are not effective against viruses, and usually physicians can just provide or recommend appropriate fluids and medication to treat the fever and any pain. And, again, the spectrum of disease with viral meningitis ranges from no symptoms or just a mild headache to significant infection with seizure and severe symptoms.
For any bacterial meningitis, you need antibiotics. It's always initially intravenous antibiotics, and physicians make decisions about the type of antibiotic based on what type of bacteria is causing the infection: meningococcal or pneumococcal. Waiting a day or even hours to treat certain kinds of bacterial infections can mean the difference between life and death. If bacterial meningitis is strongly suspected, the physician will start antibiotics that should treat the usual types of bacterial meningitis. After a laboratory confirms the identity of the bacteria, the antibiotics might be changed to optimize the therapy.
The duration of antibiotics, likewise, depends on the organism causing the infection. Surprisingly, for meningococcal meningitis, even though it is often one of the most severe forms of meningitis, you often only need five to seven days of therapy. Other types of bacterial meningitis require a longer period of treatment, depending on the bacteria and the response to therapy.
Why administer the antibiotics intravenously?
For one, it's faster delivery of the drug. It also ensures delivery of adequate amounts or levels of the antibiotic. When you're treating meningitis or any infection in the central nervous system, you need to get high levels of antibiotics to cross what's called the blood-brain barrier to actually get to where the infection is. Often medicine by mouth is not sufficient.
Who do you think should be immunized with the meningitis vaccine?
The pneumococcal vaccine is now part of routine childhood immunization. It has decreased the amount of pneumococcal meningitis infections in children. The meningococcal vaccine that is available in the United States is not effective in young children. However, studies in college-age students have shown that use of the vaccine prevents about two-thirds of the cases of meningococcal disease that we see in this age group. So, as of a few years ago, recommendations were made for the education of incoming freshman and their families by their pediatrician or by the school about immunization with the meningococcal vaccine. This vaccine should be strongly considered for all college freshmen who plan to live in a dormitory.
The vaccine covers two out of three of the main types of meningococcus bacteria that we see in the United States. And the vaccine itself is about 85 percent effective so it's not foolproof, by any means. So we always stress that even if you have received the vaccine, you still need to be evaluated if you get signs and symptoms of meningitis. Vaccine coverage is never 100 percent, plus many things can cause meningitis.
There are many studies trying to find a better meningococcal vaccine, especially in younger children, and one that offers a little bit better coverage, but that is still in the works.
People in medical research are also in the process of developing vaccines for a variety of viral infections, some of which cause meningitis. As of now, there is no vaccine available to prevent enterovirus infections, a common cause of viral meningitis.
What do you think are the most common misunderstandings or myths about meningitis?
There's such a wide spectrum of disease, ranging from some types of viral meningitis, which are very benign and often may go undiagnosed and you do totally fine, to things like meningococcal meningitis, which can be devastating if it goes undiagnosed and untreated.
So it's very difficult when someone hears "meningitis" because they usually think of worst-case scenario. Anything that might be affecting the brain is certainly of concern, though, so we need to provide good education to the parents and the children themselves about signs and symptoms of meningitis.
What is your advice to college students?
If you're a college student, you're going to be exposed to some new things and need to be aware of the infectious diseases that you might be up against. Also, if you're not feeling well, you should have access to student health services where you can be evaluated. Lastly, students should also keep in mind the usual good hygiene practices, such as hand-washing, which can decrease exposure to infections.
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