A total of 1.5 million people died from tuberculosis (TB) in 2018 (including 251,000 people with HIV). Worldwide, TB is one of the top 10 causes of death and the leading cause from a single infectious agent (above HIV/AIDS). In 2018, an estimated 10 million people fell ill with TB worldwide.
TB is caused by Mycobacterium tuberculosis and is spread primarily by airborne transmission. M. tuberculosis can affect any part of the body but is found most often in the lungs. Persons with pulmonary TB generally have a cough that produces small airborne droplets containing tubercle bacilli bacteria that can remain in the air for hours.
Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist:
TB bacteria can live in the body without making you sick. This is called latent TB infection (LTBI). In most people who breathe in TB bacteria and become infected, the body is able to fight the bacteria.
Many people who have LTBI never develop TB disease. In these people, the TB bacteria remain inactive for a lifetime without causing disease. But in other people, especially people who have a weak immune system, the bacteria become active, multiply, and can cause TB disease.
Health care personnel should be screened for TB upon hire (i.e., pre-placement). Annual TB testing is not recommended unless there is a known exposure or ongoing transmission.
TB bacteria becomes active if the immune system can’t stop them from growing. When TB bacteria are active (multiplying in your body), this is called TB disease. People with TB disease are sick. They may also be able to spread the bacteria to people they spend time with every day.
Many people who have latent TB infection never develop TB disease. Some people develop TB disease soon after becoming infected (within weeks) before their immune system can fight the TB bacteria. Other people may get sick years later when their immune system becomes weak for another reason.
A positive TB test only tells that a person has been infected with TB bacteria. It does not tell whether the person has LTBI or has progressed to TB disease.
For people whose immune systems are weak, especially those with HIV infection, the risk of developing TB disease is much higher than for people with normal immune systems.
Click on the image on the right. It compares the symptoms between LTBI and TB disease.
TB screening and testing of health care personnel are recommended as part of a TB Infection Control Plan and might be required by state regulations.
TB screening programs should include anyone working or volunteering in healthcare settings, including:
All U.S. health care personnel should be screened for TB upon hire (i.e., preplacement). The local health department should be notified immediately if TB disease is suspected. Annual TB testing of health care personnel is not recommended unless there is a known exposure or ongoing transmission.
Health care personnel with untreated LTBI should receive a yearly TB symptom screen to detect early evidence of TB disease and to evaluate the risks and benefits of LTBI treatment.
There are several treatment regimens recommended in the United States for latent TB infection. The medications used to treat latent TB infection include the following:
A tuberculosis (TB) infection control plan is part of a general infection control program designed to ensure the following:
In all health care settings, particularly those in which people are at high risk for exposure to TB, policies and procedures for TB control should be developed, reviewed periodically, and evaluated for effectiveness to determine the actions necessary to minimize the risk for transmission of TB.
The TB infection control program should be based on a three-level hierarchy of control measures and include:
Administrative controls are the first and most important level of the hierarchy. These are management measures that are intended to reduce the risk or exposure to persons with infectious TB. These control measures consist of the following activities:
The second level of the hierarchy is the use of environmental controls to prevent the spread and reduce the concentration of infectious droplet nuclei. This includes two types of environmental control.
The third level of the hierarchy is the use of respiratory-protection control. It consists of the use of personal protective equipment in situations that pose a high risk of exposure to TB disease.
Use of respiratory protection equipment can further reduce risk for exposure of health care personnel to infectious droplet nuclei that have been expelled into the air from a patient with infectious TB disease. The following measures can be taken to reduce the risk for exposure:
Click on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and recheck your answers.