What is tuberculosis?

Tuberculosis is an infectious disease caused by a germ called Mycobacterium tuberculosis. The germ usually causes an infection in the lungs, but sometimes it can affect other parts of the body.

What are the signs and symptoms of tuberculosis?

The signs or symptoms of tuberculosis are common to many other diseases. They are:

• loss of weight
• loss of energy
• poor appetite
• fever and wet cough

How is tuberculosis transmitted?

Tuberculosis is transmitted through the air from exposure to germs in the saliva of infected persons and sputum coughed up from their lungs. When an infected person coughs or sneezes, tiny droplets which contain the germs are released and can be inhaled by employees or anyone in the area. The germs inhaled through the nose and mouth reach the windpipe (trachea) and the dividing air tubes (bronchi) that lead to the lungs. The germs can spread from the initial location in the lungs to other parts of the body through the bloodstream. Within weeks from infection, the immune system which is the infection control mechanism of the human body, reacts to the germs and usually prevents them from multiplying and spreading. Not everyone infected develops the disease. In fact, about 90% of infected persons remain infected for life without having any symptoms.

A person infected with the germs who does not develop the disease cannot infect others because no germs are discharged in the sputum or saliva.

About 5% of infected persons develop the disease. These persons can transmit tuberculosis because they discharge germs in their sputum or saliva.

How is tuberculosis recognized?

Medical tests such as skin tests, chest x-ray, and sputum tests can determine if a person was exposed to the germs or whether the person has the disease.

Can tuberculosis be treated?

Tuberculosis can be treated very effectively through a combination of drugs. It is important to follow the physician's directions and take the drugs exactly as recommended. If you forget to take your pills or if you take only one of them, the tuberculosis germs might become resistant to the drugs and start growing again.

Should tuberculosis be an occupational concern?

In the workplace employees of institutions or hospitals can contract tuberculosis from persons who have not yet been diagnosed. Safe work procedure should include screening programs that will identify persons who have been exposed to the germs causing tuberculosis.

When an infectious person is identified all isolation precautions should be implemented. An infectious person should be placed in a private room. Employees entering the room should wear a protective respiratory device. The isolation room must be at negative air pressure and it must have adequate ventilation to dilute the concentration of contaminants within the room. The air from the isolation room must be directly exhausted outside.

Document last updated on April 12, 1999