OHSU

Tuberculosis

About the organism 

Tuberculosis (TB) is a disease caused by the Mycobacterium tuberculosis bacterium (MTB), a poorly staining Gram-positive bacillus. TB commonly affects the lungs; however the bacteria can also attack any part of the body (e.g. the kidney, spine, and brain).

TB is transmitted from person to person via droplets from the throat and lungs of the people with active respiratory disease. The TB bacteria are put into the air when a person with active TB disease of the lungs or throat coughs, sneezes, speaks, or sings. People nearby may breathe in these bacteria and become infected.

TB usually causes pulmonary disease, which is often diagnosed using acid-fast smears and culture. Patients with active TB must be treated for long periods with multiple antimycobacterial drugs. Many persons infected with TB have no signs and symptoms and are said to have latent TB infection (LTBI). Persons with LTBI may warrant treatment to prevent the development of active disease.

High risk groups are considered people living in urban areas, institutions (prisons, nursing homes), homeless, minorities, immigrants, drug users, people with immunosuppression or HIV, healthcare workers, and others in close contact with infected individuals.

If you see the Epic TB FYI alert screen on a patient's chart, please make sure the patient is on Airborne Precautions.

Patients with pulmonary or laryngeal disease (or suspected disease) are considered contagious. Most patients with extrapulmonary TB are not contagious because the organism is not aerosolized. Exceptions occur when some mechanism for aerosolizing the MTB organism is provided. For instance, healthcare providers have been infected by irrigating cutaneous wounds caused by MTB.

Once a person infected with active TB coughs or sneezes, small droplet nuclei (approximately 5 microns in size) can remain suspended in the air for hours. These nuclei then become dispersed widely by air currents within a room or over long distances. Airborne transmission occurs when the widely dispersed nuclei containing microorganisms become inhaled by a susceptible host, thus is the necessity for Airborne Precautions. Airborne Precautions for TB means:

  • Private room with negative air flow ventilation required and the door must remain closed at all times aside for for entering and exiting
  • Healthcare workers and support staff must wear a fitted N95 respirator mask or must use a Powered Air Purifying Respirator (PAPR) upon entering patients room
  • Screen all visitors for signs and symptoms consistent with TB and ensure that visitors perform a mask fit test prior to each room entry
  • Patients may be transported outside the room only for essential tests and procedures that cannot be competed inside the room.

For patients in the ambulatory setting, Airborne Precautions for TB means:        

  • Take the patient immediately into the examination/ procedure room with door closed 
  • If patient cannot be masked, providers must use a N-95 respirator mask in addition to following Standard Precautions
  • Visitors must follow Standard Precautions and must be screened for signs and symptoms consistent with TB

If you do not see an Epic TB FYI alert screen but suspect a patient is positive for TB, please call  the Infection Prevention & Control Dept's mainline at 503 494-6694.

Resources 

More information can be found on the following sites:

Center for Disease Control and Prevention