Central Nervous System Infections
When you think of infections, you probably think of an ear infection or strep throat. You
probably don’t think of a brain or spinal cord infection. However, bacteria and viruses can
infect these organs as well as other parts of the body. Infections of the brain and spinal cord
are not very common. But when they happen, they can be very serious. That’s why it’s
important to know their symptoms.
Encephalitisis a brain infection. If you have encephalitis, you are likely to have a fever and
headache or feel drowsy and confused. The disease is most often caused by viruses. and the
immune system tries to fight off a brain infection, just as it tries to fight off other infections.
However, this can do more harm than good. The immune system’s response may cause
swelling in the brain. With no room to expand, the brain pushes against the skull. This
may injure the brain and even cause death. Medicines can help fight some viral infections
of the brain. Others just have to run their course.
Meningitisis an infection of the membranes that cover the brain and spinal cord. If you
have meningitis, you are likely to have a fever and headache. Another telltale symptom is
a stiff neck. Meningitis can be caused by viruses or bacteria. Viral meningitis often clears
up on its own after a few days. Bacterial meningitis is much more serious (Figure20.33).
It may cause brain damage and death. People with bacterial meningitis need emergency
medical treatment. They are usually given antibiotics to kill the bacteria.
Figure 20.33: These bacteria—shown at more than 1,000 times their actual size—are the
cause of bacterial meningitis; despite their tiny size, they can cause very serious illness. ( 10 )
A vaccine to prevent meningitis recently became available. It can be given to children as
young as 2 years old. Many doctors recommend that children receive the vaccine no later
than age 12 or 13, or before they begin high school.