The term meningitis means the infection of the covering of the brain (or the meninges). Although there are multiple causes, the two major germ categories are bacterial and viral. Viral meningitis, which occurs mostly during the summer months, goes away on its own, and usually causes no significant complications. This article will discuss bacterial meningitis in children.
What are the causes of bacterial meningitis?
In children over 3 to 4 months, the main bacteria that cause meningitis are:
- Streptococcus pneumoniae (the most common)
- Hemophilus Influenzae
- Neisseria meningitidis (or meningococcus)
The first 2 bacteria, Streptococcus pneumoniae and Hemophilus influenzae are also the main bacterial causes of ear and other respiratory infections including pneumonia and sinusitis. Menigococcus has been the cause of the recent outbreaks of “meningitis”. This particular infection is discussed below in greater detail.
What are the symptoms of meningitis?
In general children with meningitis look very ill and the specific signs and symptoms vary with age. In older children, the symptoms may include:
- fever
- stiff neck
- headache
- vomiting
In younger children, especially babies less than 3 months, the symptoms are very non-specific. For example, irritability, poor feeding, increased sleepiness with or even without fever. It is therefore usually difficult to determine just by symptoms whether a baby has meningitis or not. When examining an older child the doctor can look for signs of meningitis by bending the neck and the knees. In babies, these specific signs are usually absent.
How is meningitis confirmed?
In children with suspected meningitis, the only way the diagnosis can be definitively confirmed is by a procedure called a lumbar puncture (or spinal tap). This relatively safe procedure involves placing a (hollow) needle between the spinal bones in the middle lower back after the area is frozen. Spinal fluid is then collected into small test tubes which are sent for analysis. A positive spinal tap means that a child has meningitis, and the liquid will then be tested to see which bacteria is the cause. If no bacteria are found, but the spinal fluid is abnormal, the liquid may be tested for viruses or other causes.
What are the consequences of bacterial meningitis?
Bacterial meningitis is an extremely dangerous infection. The associated problems or complications, range from brain related infection/damage (such as deafness, paralysis, seizures and even mental retardation), to spread of infection through the blood, to tragically, even death.
How is meningitis treated?
Bacterial meningitis is treated by intravenous antibiotics which fortunately have been able to decrease and/or prevent the associated potential complications. However, even despite antibiotic use the death rate from bacterial meningitis is about 10%.
What if a child comes into contact with a person who develops meningitis?
The answer depends on which bacteria are causing the meningitis. If the meningitis is caused by Hemophilus influenza or meningococcus, preventative antibiotics (usually rifampin), taken by mouth, are given to close contacts (household, barrack, dorm, school or day care). In the case of outbreaks or mini-epidemics of meningococcus, which occurred in the early 1990’s and more recently during the winter season of 2000-2001, mass vaccination may be recommended by public health authorities (see details below).
Is there a single meningitis vaccine?
Because there are several bacteria that cause meningitis there is no single “Meningitis” vaccine protecting against all of the possible bacterial causes. However, what has had a big impact on decreasing meningitis is the introduction of the Hemophilus Influenzae vaccine which is now given routinely to all children from 2 month of age. Hemophilus meningitis and other related infections have decreased significantly since the vaccination was given universally. Unfortunately, this vaccination does not protect children from the other 2 bacteria. A Streptococcus pneumoniae vaccine has been developed and recommended for all children as part of their routine immunization. This pneumococcal vaccination is good news as children can now be protected from this bacteria too.
Meningococcal infection and prevention
Meningococcus is the bacteria that has caused outbreaks across North America over the last 2 decades. Understandably the presence of a meningitis epidemic in a community is very scary. These bacteria are called Neisseria meningitidis or meningococcus and there are several types that cause infection in humans: A, B and C, Y and W. Type B strains account for most of the recent meningococcal outbreaks.
Why is meningococcal infection so dangerous?
This particular bacteria is quite dangerous because in addition to causing meningitis, it can enter the blood stream (called meningococcemia) and cause the body to go into shock, resulting in kidney failure and, unfortunately, possibly death. Tragically, the risk of dying from meningococcemia is about 17%. Therefore, not only can meningococcal infection result in meningitis, which itself is bad enough, it can cause significant damage to the rest of the body. One of the difficulties with treating meningococcemia is that it can spread so quickly and cause such an overwhelming infection that even antibiotics and other supportive treatments can’t always stop the infection, explaining why the mortality or death rate is so high.
How is meningococcus spread?
The spread is usually from direct person-to-person contact through respiratory secretions. This is why outbreaks of infection occur more frequently in crowded conditions such as in the army, schools or dormitories. People most prone to getting the infection from someone already infected are those who have had close prolonged contact. More than 50% of infections occur in children less than 5 years old. There is also a higher incidence of this infection in 15 to 24 year olds. The infections most frequently occur during the winter and spring months.
What are the symptoms of meningococcal infection?
If the child only gets meningitis, then the signs and symptoms are as described above for meningitis. However, if the infection spreads beyond meningitis into the blood, one of the main signs specific to meningococcemia, is the development of little blue/purple spots on the skin called “petechiae” which rapidly grow and spread all over the body eventually looking like large bruises. If a child ever develops such a rash, especially in the context of an outbreak of meningococcal infection, medical attention should be sought immediately. Not all petechiae are due to meningococcemia, but this should be ruled out immediately, because if meningococcemia is either suspected or confirmed, immediate treatment and monitoring are absolutely necessary.
How is meningococcal infection treated?
People with full-blown meningococcemia are very ill because of this potentially deadly infection and therefore require intensive medical therapy, support and monitoring in addition to intravenous antibiotics.
What happens to contacts of a person with meningococcal infection?
The most important thing to do is to treat the close contacts with antibiotics taken by mouth. When given promptly, preventative antibiotics have been shown to prevent infection very effectively.
Vaccination against meningococcus
Effective vaccines preventing infections form several types: A, C, Y and W have been available for a few years. There are several vaccines, some protecting against C and others against all 4 types. Very recently(2013), a new vaccine against Type B meningococcus was approved in several countries including Canada and the UK. Depending on where you are, the meningococcal vaccines may be given to children at school or available at your local clinic. Please speak to your healthcare provider or local public health agency to determine what vaccines are available and at what age.
If there is a meningococcal outbreak in our area local public health authorities may recommend mass vaccination as this has been shown to be able to stop outbreaks. It must be noted that it takes several weeks for the vaccination to protect a person, and therefore household or close contacts with people with active meningococcal infection should receive antibiotics preventatively, even if vaccinated as part of a public health campaign.
What else can parents do to protect their children?
The main thing that parents can do is be on the lookout for any petechiae or other signs of meningitis described above, especially under conditions of a local or community outbreak of infection. If parents are not sure, they should not take a chance but seek medical attention just to be on the safe side.