Dennis Wilton, age 13, of Keen, N.H., for his question:
WHAT CAUSES MENINGITIS?
Meningitis is a disease of the meninges, or coverings of the brai and spinal cord. Many different infectious agents, either bacterial or viral, may cause the disease.
Bacteria that most commonly cause meningitis are meningococcus, tubercle bacillus, influenza bacillus, pneumococcus, streptococcus and straphylococcus. Many kinds of viruses may also cause meningitis.
Meningitis is usually associated with infections that develop elsewhere in the body, such as the lungs. Germs travel from these infections to the meninges through the bloodstream. If enough bacteria reach the meninges, and if the body's defense forces are weak enough, meningitis will develop.
The disease may also result when disease producing germs invade any tissue in contact with the covering of the brain. Infections may spread from the nose, throat, sinuses and ears.
Microorganisms usually travel through the short, wide veins that meet the veins of the meninges. The microorganisms also may spread by traveling along the outer coverings of the nerves from the nose. They sometimes spread directly from infected bones, such as the sinuses and mastoid bones.
The development of sulfa drugs and a variety of antibiotics has increased the chances for recovery from meningitis. The length of time necessary for recovery depends on the severity of the infection.
Persons who come in close contact with meningitis patients often receive sulfa drugs or antibiotics to protect them from the disease.
Doctors diagnose meningitis by examining the spinal fluid. They insert a needle between the vertebrae in the lower part of the back and draw the fluid from the canal that contains the spinal cord. The diagnosis is confirmed if they find pus or an excess of white blood corpuscles.
What are the symptoms of the disease? Meningitis usually starts with severe headaches, nausea, vomiting and a rise in temperature. A spasm of the neck and back muscles pulls the head back. This spasm may be so severe that the patient cannot bend his head forward.
The back may also be bowed backward. The patient may become delirious and then fall into a coma.
Epidemic cerebrospinal meningitis is the term often applied to meningitis caused by meningococcus bacteria. This microorganism causes more cases of meningitis than any other germ, but the cases seldom reach epidemic form.
This type of meningitis, commonly called spinal meningitis, usually is primary. This means that it reaches the brain directly from the nose and throat, without any infection developing there first.
Sometimes the blood is heavily infected with meningococci. This most frequently happens in infants. In such instances, spots appear all over the body. Because of these spots, the disease was once called spotted fever.