Tuberculosis (TB) Frequently Asked Questions (FAQs)

What Is Tuberculosis (TB)?

Tuberculosis (TB) is a bacterial disease that usually attacks the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain. Not everyone infected with TB bacteria becomes sick. As a result, 2 TB-related conditions exist: latent TB infection (LTBI) and TB disease. If not treated properly, TB disease can be fatal.

What is latent TB infection?

Latent TB infection (LTBI) means TB bacteria are in the body but the person is not sick and has no symptoms. In latent TB, the person has a positive TB skin or blood test, a normal chest x-ray, no symptoms and no TB germs are found in the sputum (phlegm).

What is TB disease?

TB disease is when the person has symptoms, a positive TB skin or blood test, a chest x-ray showing TB disease (if disease is in the lungs) and TB germs are found in the sputum (phlegm).

What are the symptoms of TB?

Symptoms of TB include a low-grade fever, night sweats, weakness or tiredness, and weight loss. If TB is in the lungs, the person may also cough, have chest pain, shortness of breath or might be coughing up blood. Other symptoms depend on the part of the body affected by the TB germs.

How soon do symptoms appear?

Most people infected with the germ that causes TB never develop TB disease. If TB disease does develop, it can occur 2 to 3 months after infection or years later. The risk of TB disease lessens as time passes. Treatment can prevent the development of disease.

How is TB spread?

TB is spread through the air when a person with untreated TB disease of the lungs coughs, sneezes, laughs, or sings. A person must be in close contact with someone with untreated TB disease of the lungs for a long period of time and needs to breathe in TB germs for infection to occur. In order to spread the TB germs, a person must have TB disease of the lungs or throat. Having latent TB infection is not enough to spread the germ. However, people with latent TB infection may develop TB disease in the future. To prevent developing TB disease, people with latent TB infection should take medicine.

How is TB NOT spread?

TB is NOT spread by shaking someone’s hand, touching toilet seats, sharing silverware or cups or by kissing someone.

When and for how long is a person able to spread TB?

A person with TB disease may be able to spread the TB germs until he/she has been on medicine for several weeks. However, a person with latent TB infection, but not disease, cannot spread the infection to others since there are no TB germs in the sputum (phlegm).

How do you test for TB?

There are two kinds of tests that are used to detect TB bacteria in the body: the TB skin test (TST) and TB blood tests. A positive TB skin test or TB blood test only tells that a person has been infected with TB bacteria. It does not tell whether the person has latent TB infection (LTBI) or has progressed to TB disease. Other tests, such as a chest x-ray and a sample of sputum, are needed to see whether the person has TB disease.

What is the treatment for TB? 

People with latent TB infection should be seen by a health care provider for treatment, which usually includes taking medication for three to nine months. People with TB disease must take several medications for six months or more.

Additional Resources


Phone: (716) 858-7690

Fax: (716) 858-8701

Erie County Department of Health (ECDOH)
95 Franklin Street
Buffalo, New York 14202

ECDOH Locations

Western New York 211