Tuberculosis (TB) is an airborne bacterial infection. TB prevention measures involve stopping the bacteria from spreading and treating asymptomatic infection before it progresses to active disease.

Active TB disease without proper treatment can be life threatening. Symptoms include chest pain, shortness of breath, and persistent cough.

Sometimes, people can carry the TB bacterium with no symptoms. This is known as latent TB or TB infection.

People with latent TB are at risk of developing TB disease. This may not happen for months or even years until something interferes with their immune system function and allows the bacteria in their lungs to multiply.

This article discusses TB prevention, including how the bacteria spreads, how to reduce transmission, who is most likely to develop TB disease, and whether vaccination is necessary.

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TB is an airborne infection. The infectious agent responsible is the bacterium Mycobacterium tuberculosis (M. tuberculosis).

A person with active TB disease can spread it with any action that causes the bacteria in their lungs and throat to become airborne.

Examples include:

  • coughing
  • sneezing
  • singing
  • speaking
  • yelling
  • laughing
  • playing a wind instrument

When another person inhales the bacteria, it enters their lung tissue, where it can cause active disease or remain latent.

A person with latent TB cannot spread the bacteria to others.

M. tuberculosis usually transmits from the lungs and throat. This means people cannot spread the bacteria from other locations such as their spine or kidneys.

Since TB usually spreads through inhalation of M. tuberculosis, a person cannot become infected through contact such as:

  • handshakes
  • shared dishes
  • toilet seats or faucets

Read more about how TB spreads.

TB infection is a reportable disease by law. The Centers for Disease Control and Prevention (CDC) state that people should report suspected or confirmed cases of TB to the designated department or official within 24 hours.

Contact details can be found by searching the internet for “how to report TB,” followed by the department a person is in.

Anyone with reason to believe a person has TB must report it to their local health officer or department.

It is possible to control the spread of TB with some preventive measures.

Early diagnosis

TB testing can identify latent TB so a person can get prompt treatment. This may prevent their condition from progressing to active disease, during which the TB bacteria can spread to others.

Treatment for latent TB is usually a daily dose of an antibiotic for 6–9 months.

Workplace prevention and control

Some jobs, such as in healthcare, increase a staff member’s chances of TB exposure.

Employers in these settings can maintain a TB prevention program and support the timely identification of people who carry the TB bacteria.

Physical distancing

A person with active TB disease should stay away from others while there is a chance of M. tuberculosis transmission.

Transmission can occur when a person has active symptoms such as coughing and flu-like symptoms.

Household contacts are at high risk of TB infection, and doctors may recommend they receive preventive treatment. Screening may also be necessary. A doctor can monitor the effects of treatment to determine when the chance of bacteria spread has passed.

Air quality measures

A person with TB disease can reduce the amount of bacteria in the air by:

UV light

An article from 2019 discusses how, under controlled conditions, UV radiation may prevent the spread of M. tuberculosis. It does this by changing the bacteria’s genetic material so it cannot reproduce.

Guidance from the CDC and the National Institute for Occupational Safety and Health states that upper-room ultraviolet germicidal irradiation (UVGI) lamps may kill or inactivate airborne TB bacteria and lower the risk of infection for people in the room. They are particularly helpful in healthcare settings.

However, UV light can damage the skin and eyes. Installing the lamps out of sight in heating, ventilation, and air conditioning (HVAC) systems or high up in a room can reduce this risk, but technicians who service the lights should wear protective equipment.

UV air purifiers are another option. However, they can emit ozone, which may cause breathing difficulties. The California Air Resources Board has a list of electronic air cleaners that tests found to emit less than 0.05 parts per million of ozone.

Anyone with exposure to TB bacteria can develop TB disease, but certain people are more likely to get sick sooner.

They include:

  • children under 5 years old
  • older adults
  • people who have had a TB infection in the last 2 years
  • those who use injectable illegal drugs
  • people who have received incomplete TB treatment in the past
  • those with low body weight
  • people receiving immunosuppressant therapy
  • low-income or medically underserved populations
  • those who have had intestinal bypass or gastrectomy surgery
  • people who drink large quantities of alcohol

Certain medical conditions can also increase a person’s chance of becoming sick with TB, such as:

The vaccine for TB is Bacille Calmette-Guérin (BCG).

The Advisory Committee on Immunization Practices does not recommend the BCG vaccine for most people in the United States.

This is because of the low rate of TB infection in the U.S. and how the vaccine can cause a false-positive reaction to the TB skin test. In addition, the vaccine is not always effective against pulmonary TB in adults.

Learn more about the BCG vaccine and who is eligible.

TB is an airborne bacterial infection. It can spread when a person with TB coughs or sneezes to send the bacteria into the air and another person breathes it in.

Prevention includes prompt treatment of latent TB, plus air quality control measures such as ventilation and masking.

TB vaccination is not necessary in the U.S. for most people.