![People still get TB (tuberculosis), an infectious disease that causes a persistent cough and coughing up blood and sputum, and it is highly contagious. TB is not common in the U.S., but it is a leading cause of death in other parts of the world.](https://images.medicinenet.com/images/article/main_image/tuberculosis-tb-disease.jpg?output-quality=75)
TB (tuberculosis) is an infectious disease caused by Mycobacterium tuberculosis bacteria that usually affects the lungs.
People still get TB and the disease is highly contagious. It is not common in the U.S., but it is a leading cause of death in other parts of the world.
There are two TB-related conditions:
- Latent TB infection
- The body is able to fight the bacteria
- The patient has no symptoms
- Cannot be spread to others in this stage
- Patients usually have a positive TB skin test reaction or positive TB blood test
- TB disease may develop if treatment is not received for latent TB infection
- TB disease
- Patients are sick and symptomatic
- Patients are contagious
- The risk of developing TB disease is increased in people with weakened immune systems
What Are Symptoms of TB?
Symptoms of active tuberculosis disease include:
- A persistent cough that lasts 3 weeks or more
- Coughing up blood or sputum
- Fever
- Chills
- Fatigue
- Weakness
- Sweating at night
- Loss of appetite
- Weight loss without trying
- Chest pain
How Is TB Diagnosed?
TB (tuberculosis) is diagnosed with the following tests:
- Tuberculin skin test, sometimes also called a purified protein derivative test (PPD)
- A shot in the arm containing tiny pieces of dead TB bacteria is administered
- Two to three days later, injection site is examined for evidence of a skin reaction (redness or swelling) and the extent of the reaction
- Skin tests are usually positive within 4 to 10 weeks after exposure
- Blood test (interferon-gamma release assays [IGRAs])
- Blood tests are available in many areas, but not everywhere
Latent tuberculosis infection is diagnosed with a positive skin test or blood test, followed by a physical examination and imaging such as a chest X-ray to make sure the TB is not active and causing disease.
What Is the Treatment for TB?
TB (tuberculosis) can be cured; however, treatment regimens last for months and patients must take all medicines for the duration they are prescribed, exactly as prescribed.
- If patients stop taking medications before the prescribed course is finished, or they do not take medications as directed, they can become sick again and they may be resistant to the initial medications.
- Drug-resistant TB is more difficult and more expensive to treat.
- Untreated tuberculosis can be deadly.
Treatment for latent tuberculosis infection usually lasts 3 months or longer and includes:
- There are several different drug regimens:
- Rifampin daily for four months
- Isoniazid plus rifampin daily for three months
- Isoniazid plus rifapentine weekly for three months (usually given weekly by a trained health care worker)
- An alternative is isoniazid daily for six or nine months for people who cannot take rifampin or rifapentine
- People treated for latent TB infection are usually monitored once a month by a doctor to check for signs of medication toxicity, such as liver damage
Treatment for active tuberculosis disease usually lasts 6 to 9 months and includes:
- First-line anti-TB agents that form the core of treatment regimens are:
- Isoniazid
- Rifampin
- Ethambutol
- Pyrazinamide
- Regimens for treating TB disease have an intensive phase of 2 months, followed by a continuation phase of either 4 or 7 months (total of 6 to 9 months for treatment)
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https://www.cdc.gov/tb/default.htm