Pam Duncan, age 13, of Erie, Pa., for her question:
HOW DOES TUBERCULOSIS ENTER THE BODY?
Tuberculosis is an infectious disease that often takes many months or even years to cure. It is caused by a rod shaped germ, the tubercle bacillus, that is so small it can only be seen under a microscope.
Scientists say that most of the germs that cause the serious infection are breathed in with air. The germs can be spread by persons who have pulmonary or lung tuberculosis. When these people cough, droplets of moisture that contain the germs are put out into the air. Then others can breathe the airborne germs.
Contaminated food or milk can also carry the tuberculosis germs to the victim's body, although this isn't often the case.
Germs that enter the body usually lodge in the lungs. When they land, the body's defenses go to work. White cells, which act as the body's germ fighters, surround the invaders and try to destroy them.
Sometimes the body also builds a wall of cells and fibers around the germs to confine them. This formation becomes a small, hard lump called a tubercle. The name tuberculosis comes from tubercle.
The germs can't cause more damage as long as their walls remain unbroken. But if the body defenses become weakened later in life, the germs can again multiply and make the person sick.
This first invasion of germs and the walling off of the germs is called a "primary infection." Persons with this type of infection may never know that tuberculosis germs ever entered their bodies since they usually never develop signs of the disease. But they are tuberculin positive. This means they are positive on the tuberculin test.
Germ fighters can't always fight off all germ attacks. When they fail, the infection advances and develops into an active or "open" one.
Tuberculosis symptoms vary. Usually the person first notices a slight dry cough. Then his temperature may rise late in the afternoon. Often he thinks he has an ordinary cold. The symptoms persist and then there's an almost constant fever and cough. He may lose weight and feel chest pains.
Because early symptoms of tuberculosis are so vague, doctors use a number of methods to help diagnose the disease: physical exams, lab tests, skin tests and X rays.
Laborataory tests can tell a doctor if a patient has tuberculosis and whether it is progressing. Skin tests are helpful in pointing out an inactive primary infection. They are also useful in distinguishing between tuberculosis and other infections that have similar symptoms.
X rays give doctors a chance to examine the lungs.
Treatment today involves the use of special drugs. At one time doctors recommended complete bed rest for all tuberculosis patients. Now, however, most doctors say that adequate chemotherapy, or use of drugs, can eliminate the need for complete bed rest in most cases.