Posted on August 10 2018
Meningitis is an inflammation, or swelling, of the protective membranes that cover the brain and spinal cord. The swelling is typically caused by a bacterial or viral infection of the fluid that surrounds the brain and spinal cord. However; there are certain injuries, medications, cancers, and other types of infections that can cause meningitis. It is crucial to know the specific cause of meningitis because the treatment differs depending on the cause.
There are six different types of meningitis: bacterial, viral, fungal, parasitic, amebic, and non-infectious meningitis. The most common types are bacterial and viral.
Bacterial Meningitis is a very serious disease and can be deadly. Death can actually occur in as little as a few hours, if not treated immediately. In fact, between 5 to 40 percent of children, and 20 to 50 percent of adults with this condition die from it. Most people do recover from meningitis, however; permanent disabilities, such as brain damage, hearing loss, and learning disabilities can result from the infection.
There are five types of bacteria that can cause meningitis. The leading causes in the United States include:
- Streptococcus Pneumoniae: or, pneumococcus. This bacterium is the most common cause of bacterial meningitis in infants, young children, and adults. This type of bacteria is usually found in the respiratory tract, sinuses, and nasal cavity, and often causes pneumonia, ear and sinus infections. This can also cause pneumococcal meningitis. There is a vaccine that can help prevent this infection.
- Neisseria Meningitidis: or, meningococcus. This bacterium is another leading cause of bacterial meningitis. These bacteria commonly cause an upper respiratory infection, but can cause meningococcal meningitis when they enter the blood stream. This is a highly contagious infection that is spread through saliva and other respiratory fluids. It causes meningococcal meningitis, which affects mainly teenagers and young adults. It has been known to cause local epidemics in college dormitories, boarding schools, and even military bases. A vaccine can also help prevent this infection.
- Haemophilus Influenzae: or, Haemophilus. Haemophilus Influenzae Type B (HIB) bacterium was once the leading cause of bacterial meningitis in children. In addition to meningitis, it can also cause blood infections, inflammation of the windpipe, cellulitis, and infectious arthritis. But, new HIB vaccines have greatly reduced the number of cases of this type of meningitis.
Listeria Monocytogenes: or, Listeria. This bacteria can be found in unpasteurized cheeses, hot dogs, and lunch meats. Pregnant women, newborns, older adults, and people with weakened immune systems are most susceptible. Listeria can cross the placental barrier, and infections in the later stages of pregnancy may be fatal to the baby.
Staphylococcus Aureus: which is typically found on the skin and in the respiratory tract, and causes staphylococcal meningitis.
These forms of bacteria can also be associated with another serious illness called sepsis. Sepsis is the body's overwhelming and life-threatening response to infection that can cause tissue damage, organ failure, and death.
Causes of Bacterial Meningitis
The causes of this type of meningitis vary by age group:
- Newborns: Group B Streptococcus, Streptococcus Pneumoniae, Listeria Monocytogenes, Escherichia Coli
- Babies & Children: Streptococcus Pneumoniae, Neisseria Meningitidis, Haemophilus Influenzae Type B, Group B Streptococcus
- Teens & Young Adults: Neisseria Meningitidis, Streptococcus Pneumoniae
- Older Adults: Streptococcus Pneumoniae, Neisseria Meningitidis, Haemophilus Influenzae Type B, Group B Streptococcus, Listeria Monocytogenes
Risk Factors for Bacterial Meningitis
Certain people are at an increased risk for bacterial meningitis. Some of the risk factors include:
- Age: Babies are at an increased risk for bacterial meningitis compared to people in other age groups, but people of any age can still develop bacterial meningitis.
- Community Setting: Infectious diseases tend to spread where large groups of people gather together. College campuses have reported outbreaks of meningococcal disease, caused by N. Meningitidis.
- Certain Medical Conditions: for example - people without a spleen, or have a spleen that doesn't work properly, are at an increased risk.
- Working with Meningitis Causing Pathogens: for example, microbiologists routinely exposed to meningitis causing bacteria are at an increased risk.
How Bacterial Meningitis Spreads
Generally, the germs that cause bacterial meningitis spread from one person to another. Certain germs, such as Listeria and E. Coli, can spread through contaminated food. How people spread the germs often depends on the type of bacteria. It's important to know that people can carry these bacteria in or on their bodies without being sick. These people are called carriers - and while most carriers never become sick, they can still spread the bacteria to others.
- Mothers can pass Group B Streptococcus and Escherichia Coli to their babies during labor and birth.
- People spread N. Meningitidis by sharing respiratory or throat secretions - saliva or spit - and typically occurs during close contact, such as coughing, or kissing.
- People can get E. Coli by eating food prepared by people who didn't wash their hands well after using the bathroom.
Signs & Symptoms of Bacterial Meningitis
In newborns and babies, the meningitis symptoms of fever, headache and neck stiffness may be absent or difficult to notice. The baby may be irritable, vomit, feed poorly, or appear to be slow or inactive. In young babies, doctors may also look for a bulging soft spot on the infant's head, or abnormal reflexes. If you think your child has any of these symptoms, contact the doctor immediately.
Symptoms of bacterial meningitis can appear quickly or over several days. Typically, they develop within three to seven days after initial exposure. Later symptoms of bacterial meningitis can be very serious - such as seizures or coma. For this reason, it is imperative that anyone who thinks that they may have meningitis should see a doctor as soon as possible.
Diagnosis & Treatment of Bacterial Meningitis
If a doctor thinks you have meningitis, they will collect samples of blood or cerebrospinal fluid. A lab will test the samples to see what is causing the infection. As mentioned above, it is important to know the specific cause of meningitis, so that the doctors know how to properly treat it.
Doctors treat bacterial meningitis with a number of antibiotics. It is critical to start treatment as soon as possible.
Prevention of Bacterial Meningitis
The most effective way to protect against certain types of bacterial meningitis is to get vaccinated. There are vaccines for three types of bacteria that can cause meningitis: N. Meningitidis, Streptococcus Pneumoniae, HIB. Be sure to receive these vaccinations as scheduled.
As with any vaccine, the vaccines that protect against these bacteria are not 100% effective. The vaccines also do not protect against all the strains of each bacteria. For these reasons, there is still a chance to develop bacterial meningitis even if you were vaccinated.
Pregnant women should speak to their doctor about getting tested for Group B Streptococcus. Women receive the test between 35 to 37 weeks of pregnancy. Doctors administer antibiotics during labor to women who test positive in order to prevent passing Group B Strep to their newborns. Pregnant women can also reduce their risk of meningitis caused by Listeria by avoiding certain foods, and safely preparing others.
If someone has bacterial meningitis, a doctor may recommend antibiotics to help prevent other people from getting sick. This is called prophylaxis, and is recommended for close contacts of someone with meningitis caused by N. Meningitidis, or family members, especially if they are at an increased risk of someone with a serious HIB infection.
Your doctor or local health department will tell you if you or someone in your home needs prophylaxis.
You can also help protect yourself and others from bacterial meningitis by maintaining healthy habits, such as: not smoking and avoiding cigarette smoke, getting plenty of rest, and avoiding close contact with people who are sick.
Any form of meningitis is serious and needs to be treated as a medical emergency. Please stay tuned for upcoming blog posts on the next common form of meningitis: viral meningitis. Following that, in our Part 3 post, we will also explain the various other, less common forms of meningitis as well.