Key points
- Tuberculosis (TB) is a contagious infectious disease that mainly affects the lungs.
- It is caused by bacteria called Mycobacterium tuberculosis.
- It spreads in healthcare and other settings where people gather.
- TB is preventable and treatable.
Overview
TB is a risk in healthcare and other congregate settings where people share the same space for extended time. Examples of congregate settings include:
- Prisons
- Jails
- Homeless shelters
- Social assistance shelters
- Emergency shelters
This disease often spreads when patients, prisoners, or shelter clients have unrecognized TB. It can also spread when people with active disease receive ineffective or incomplete medical treatment.
Risk factors
TB is a contagious and potentially life-threatening infectious disease caused by bacteria called Mycobacterium tuberculosis. The bacteria spread from person to person through the air. People with symptoms have active TB and can spread the disease. The risk of developing active TB is greatest in the first few years after infection. However, some risk remains throughout life.
Examples of ways people with active TB release bacteria into the air include:
- Coughing
- Sneezing
- Talking
- Singing
The small droplets containing the bacteria quickly dry into tiny particles called droplet nuclei. The nuclei can remain suspended in air for long periods of time and other people can breathe the particles into their lungs. Becoming infected with TB typically requires an extended amount of time sharing a space with a person who has active TB. However, in rare cases the infection has been documented after short exposures.
People who have been infected but do not have symptoms have latent TB infection and are not contagious. Once infected, most people's immune system can control the infection. However, they are not able to completely eliminate it without taking a proper course of anti-TB drugs. Depending on the level of infection and strain of bacteria, anti-TB drug regimens can last from 4 months to over a year. Without treatment, latent TB can develop into active TB and become contagious.
TB is preventable and treatable in most cases. It can usually be cured by available anti-TB drugs. Infection control practices can help reduce the spread of TB. Treatment for latent TB infection can prevent others from developing active TB. Persons with drug-resistant strains can recover using alternative regimens of medications, except in extreme cases.
Reducing risk
A TB infection control program should be based on the following three levels of the hierarchy of controls:
- Engineering Controls – Isolate people from the hazard.
- Administrative Controls – Change the way people work.
- Personal Protective Equipment - Incorporate respiratory protection.
The minimum level of respiratory protection acceptable for TB is a NIOSH-approved N95 filtering face piece respirator. For more information on respirators and establishing a respiratory protection program, go to the NIOSH Respirators page.
Additional Respirator Information
Respirators: Your TB Defense - Streaming videos about respiratory protection against TB.
NIOSH-Approved Disposable Particulate Respirators (Filtering Facepieces)
TB Respiratory Protection Program in Health Care Facilities – Administrator's Guide
Protect Yourself Against Tuberculosis – A Respiratory Protection Guide for Health Care Workers
Resources
Regional Tuberculosis Training and Medical Consultation Centers (RTMCC)
Curry International Tuberculosis Center
Global Tuberculosis Center at Rutgers, the State University of New Jersey
Mayo Clinic Center for Tuberculosis (MCCT)
Southeastern National Tuberculosis Center
