Meningitis is a medical term for inflammation of the tissues surrounding the brain. Whether bacterial or viral, the symptoms are often the same, including fever, headache, stiff neck, nausea, vomiting, and sometimes sleepiness, confusion, and sensitivity to bright light. In infants, meningitis symptoms may be more difficult to identify and include such things as fretfulness or irritability, difficulty in waking, or refusal to eat.
A proper diagnosis of meningitis requires a spinal tap, where a physician draws fluid from the spinal column into a syringe and a laboratory examines it for the presence of viruses or bacteria. This fluid is normally sterile, so the presence of any viruses or bacteria in spinal fluid is a cause for concern. Viral meningitis can be caused by a wide variety of viruses, although enteroviruses are the most common. Bacterial meningitis can be caused by several different bacteria, including Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae type b.
Click for fact sheets on viral meningitits and meningococcal meningitis.
Two vaccines are available for Neisseria meningitidis, and the intent is to prevent disease in persons living in crowded conditions. The first, meningococcal conjugate vaccine (MCV4), is currently recommended at the adolescent visit (age 11-12) or at high school entry (age 15). This is primarily in an effort to reduce the number of meningitis cases among new military recruits and college students, who often live in crowded conditions where spread of the bacteria is easy and rapid. College freshman should also be vaccinated, ideally with MCV4, although meningococcal polysaccharide vaccine (MPSV4) is an acceptable alternative. Many colleges require a physical exam before the start of freshman year, so rising freshmen should check their status and request vaccination at that time. Meningococcal vaccine is not routinely required for young children, unless they have certain high-risk medical conditions.
Streptococcus pneumoniae occurs as 90 different serotypes, and two vaccines are available. The first, recommended for all infants beginning at 2 months, is the pneumococcal conjugate vaccine (PCV). This vaccine provides protection against the 7 serotypes responsible for most cases of pneumococcal meningitis. For individuals with certain high-risk conditions, a pneumococcal polysaccharide vaccine (PPV) is also available, and this vaccine provides protection against 23 common pneumococcal strains. The CDC has concluded that most cases of pneumococcal meningitis occuring in vaccinated persons are caused by a strain not covered by the current vaccines.
There are also multiple serotypes of Haemophilus influenzae, though type b (Hib) is the most pathogenic. Before the introduction of a Hib vaccine in the 1990s, this was the most common cause of bacterial meningitis in children under 5.
Ensuring that children are appropriately immunized can save lives, so check with your pediatrician to find out whether your child is up-to-date. Click for a complete childhood immunization schedule.