How Does Pulmonary Tuberculosis Spread?

Pulmonary tuberculosis (TB) is a bacterial infection of the lungs caused by the organism Mycobacterium tuberculosis. TB is an airborne disease, meaning it spreads from person to person through tiny droplets in the air. Although tuberculosis is most often found in the lungs, it can develop in other parts of the body, as well. It’s important to note that untreated pulmonary tuberculosis can be fatal, but taking medication as prescribed by your doctor almost always cures it.^[1]

Latent vs Active Tuberculosis

Tuberculosis can be either latent or active:^[2]

• Having latent TB means you’ve been infected with the TB bacteria, but your immune system has prevented it from becoming active. This means you don’t have symptoms of TB and you can’t spread it to another person. But please remember – latent TB can progress to active TB.
• Having active TB disease means you’ve been infected with the TB bacteria, you have symptoms of active disease and you can spread it to other people.

How is Pulmonary TB Spread to Other People?

Pulmonary tuberculosis spreads through tiny, airborne droplets released into the air when someone with active disease coughs, sneezes, talks, laughs or sings. If you breathe in these droplets, you can become infected.²

Yes, the disease is contagious, but unlike the common cold or flu, it doesn’t thrive on surfaces; you can’t catch it by merely shaking someone’s hand who has it or by touching a surface an infected person has previously touched. You must be in close contact with someone who has active disease over a period of time. That’s why the disease is most often spread among co-workers, friends and family members who live and work in close contact with each other.²

Symptoms of Pulmonary Tuberculosis

Initially symptoms of active pulmonary TB may be so mild they’re not noticeable. As the disease progresses, symptoms may include:²

• A cough that lasts longer than two weeks and produces, thick, cloudy and (sometimes) bloody mucus (sputum)
• Fatigue
• Loss of appetite and weight loss
• Fever
• Night sweats
• Rapid heartbeat
• Swollen lymph glands (found in the neck)
• Shortness of breath
• Chest pain (in rare cases)

Who’s at Risk?

People who live and work in close contact with others who are sick are at highest risk for catching the disease. This includes:¹

• Friends and family members of a person with active TB disease.
• People who have emigrated from other parts of the world where there are high rates of TB.
• People in groups that are considered high risk including the homeless, IV drug users and people with HIV.
• People who live and work in places that house people who are high risk for the disease, including hospitals, homeless shelters, correctional facilities, nursing homes and residential homes for people who have HIV.

Not everyone infected with the TB germ will develop active TB disease. People at highest risk for developing active disease include those with weakened immune symptoms such as:

• Infants and young children
• People with chronic (ongoing) diseases such as diabetes, kidney or lung disease
• People with HIV or AIDS
• Organ transplant recipients
• Cancer patients who are undergoing chemotherapy
• People who are receiving specialized treatment for autoimmune disease such as rheumatoid arthritis or Crohn’s disease

How is TB Diagnosed?

TB can be diagnosed through a skin test or TB blood test. If you have a positive skin test, it only means you’ve been infected with the TB germ. You’ll be given additional tests such as a chest X-ray and sputum test to determine if you have active TB disease.

Treatment of Pulmonary Tuberculosis

Treatment of pulmonary TB depends upon whether you have latent or active disease. For example, if you have:¹

• Latent TB disease, you should have preventative treatment which consists of a daily dose of isoniazid (INH), the most common preventative therapy for 6 to 9 months.
• Active TB disease, you should have a combination of several drugs which may include INH plus rifampin, pyrazinamide and ethambutol for 6 to 12 months. You may have to be admitted to the hospital for a short period of time but after a few weeks, you should be able to continue your treatment at home; you won’t be considered contagious and you should be able to resume your normal activities.

The most important aspect of TB treatment is to continue taking your medication under medical supervision for the entire length of therapy.¹ Doing otherwise can lead to antibiotic resistance and increase the risk of severe illness and death.

Preventing Tuberculosis

To reduce the chances of you getting active TB disease, consider the following preventative tips:²

• Avoid spending long periods of time in closed, cramped quarters with anyone who has active TB unless they’ve been treated for at least 2 weeks.
• If you work in a facility that houses people with untreated TB, make sure you wear an N95 respirator or another specialized respirator designed for prevention of TB and other airborne diseases.
• If you live with someone with active TB, encourage them to comply with their treatment instructions.

For more information about pulmonary tuberculosis or to get a TB skin test, talk to your primary health care provider.

_{[1] American Lung Association. Learn About Tuberculosis. Last reviewed October 11, 2016.}

_{[2] WebMD. Tuberculosis (TB) – Topic Overview. Accessed January 20, 2018.}