Meningitis
What Is Meningitis
Meningitis (inflammation of the linings of the brain) can be caused by many types of organisms, such as bacteria and viruses.
Meningococcal meningitis is caused by a specific bacterium known as N. meningitides. In addition to several types of N. meningitidis, another common bacterium that can cause meningitis is called Streptococcus pneumoniae. There are 83 known types of Streptococcus pneumoniae. Usually this streptococcus bacteria causes pneumonia in the lungs. However, this organism may spread through the blood to infect the linings of the brain.
In countries where the disease is common, up to 5 to 10 percent of the general population will carry the N. meningitidis bacterium in their nose or throats.
Another form of meningitis is called aseptic meningitis. The most common cause of aseptic meningitis is a viral infection, and enteroviruses are common causes of viral meningitis, especially in children during the summer months. However, aseptic meningitis may be caused by other viruses, such as arboviruses, HIV, herpes simplex virus (HSV) types 1 and 2, some bacteria, fungi, and parasites. Most people who get infected with enteroviruses are asymptomatic or have only a general febrile illness.
How Do You Get Meningitis?
Person-to-person transmission occurs by inhaling respiratory droplets containing the bacteria or virus or by close contact with an infected person’s respiratory secretions or saliva.
Enteroviruses are most often spread via the fecal-oral route from person to person through fecal contamination of water or food or contact with contaminated inanimate objects. Enteroviruses can also be spread through respiratory secretions (saliva, sputum, or nasal mucus) of an infected person
Susceptibility and Resistance
General susceptibility is low. The disease is most common in very young children or young adults. Excessive crowding contributes to the spread of bacterial meningitis. Susceptibility generally decreases with age.
What Are The Symptoms?
The illness usually involves the sudden onset of fever, severe headache, a stiff neck, nausea with some vomiting, and may be accompanied by a small rash. The patient may become confused and delirious and enter into a coma, sometimes very quickly after the onset of the illness. Unless the illness is diagnosed early and treated rapidly and aggressively with antibiotics and other supportive measures, the fatality rate can be quite high. With early and aggressive treatment with antibiotics for bacterial meningitis, the death rate has been reduced to between 5 and 15 percent.
Antibiotics are not effective for aseptic meningitis caused by viruses. However, most people who get infected with enteroviruses are asymptomatic or have only a general febrile illness.
Preventative Measures
Vaccination against meningitis caused by the bacteria, N. meningiditis, is recommended for people who travel or reside in the countries where epidemics occur, i.e. sub-Saharan Africa. Vaccination may also be recommended when there are many cases or an outbreak of this bacteria in other areas. The US Centers for Disease Control and Prevention recommends vaccination with a meningococcal conjugate vaccine for all preteens and teens at 11 to 12 years old, with a booster dose at 16 years old. Teens and young adults (16 through 23 year olds) also may be vaccinated with a serogroup B meningococcal vaccine. if they: have disorders such as a damaged or an absent spleen, a compromised immune system or are part of a population identified to be at increased risk because of a serogroup B meningococcal disease outbreak.
For people who have been in direct contact with persons with bacterial meningitis, antibiotics are recommended for prevention of the disease for exposed persons. Sporadic isolates of ciprofloxacin-resistant meningococcal disease have appeared in the Americas, Europe, Australia, China, and India. As a result, the US Centers for Disease Contorl and Prevention recommends that ciprofloxacin should no longer be used for chemoprophylaxis of meningococcal disease in communities where ciprofloxacin-resistant strains have been identified. Ceftriaxone, rifampin and azithromycin are now recommended.
Following general food and water precautions and maintaining careful personal hygiene will help prevent aseptic meningitis caused by enteroviruses.
Treatment
Early and aggressive treatment with a variety of commonly available antibiotics is generally effective. For aseptic meningitis, only general supportive measures are available.
Medications
Vaccinations
Where Does It Commonly Occur?
Meningococcal infections are found just about anywhere in the world and cases are generally sporadic. The sub-Saharan countries of Africa regularly experience epidemics of bacterial meningitis during the dry season, usually from December through April. These countries are known as the sub-Saharan meningitis belt and include The Gambia, Senegal, Mali, Burkina Faso, Ghana, Niger, Nigeria, Cameroon, Chad, Central African Republic, Sudan, Uganda, Kenya, Ethiopia, and Eritrea.
Enteroviruses that are the main cause of aseptic meningitis are found worldwide.
