What is tuberculosis?
Tuberculosis is an infectious disease that can cause infection in the lungs or other tissues. It commonly affects the lungs, but it can also affect other organs such as the spine, brain, or kidneys. The word “tuberculosis” comes from a Latin word for “nodule” or something that protrudes.
Tuberculosis is also known as TB. Not everyone who gets infected with TB gets sick, but if you do get sick, you should get treatment. If you are infected with the bacteria but do not have symptoms, you have inactive TB or latent TB infection (also called latent TB). The TB may seem to have gone away, but it is latent (sleeping) inside your body. If you are infected, develop symptoms and are contagious, you have active tuberculosis or tuberculosis disease (TB disease).
The three stages of tuberculosis are:
- Primary infection.
- Latent tuberculosis infection.
- Active tuberculosis disease.
How common is tuberculosis?
About 10 million people got sick from Tuberculosis (TB) worldwide, and about 1.5 million people died from the disease in 2020. TB was once the leading cause of death in the US, but the number of cases dropped rapidly in the 1940s and 1950s after investigators uncovered deals. Statistics show that 7,860 cases of tuberculosis were reported in the US in 2021. The national incidence rate is 2.4 cases per 100,000 people.
Are there different types of tuberculosis?
In addition to active or inactive, you may hear about different types of TB, including pulmonary (lung) tuberculosis, the most common. But the bacteria can also affect other parts of your body besides your lungs, causing extrapulmonary tuberculosis (or TB outside the lung). You may also hear about systemic miliary tuberculosis, which can spread throughout the body and cause:
- Meningitis is an inflammation of your brain.
- Sterile pyuria or elevated levels of white blood cells in the urine.
- Pott’s disease is also called spinal tuberculosis or tuberculous spondylitis.
- Addison’s disease is a condition of the adrenal glands.
- Hepatitis is an infection of the liver.
- Lymphadenitis in the neck is also called scrofula or tuberculous lymphadenitis.
What causes tuberculosis?
Tuberculosis is caused by the bacterium Mycobacterium tuberculosis. The germs are spread through the air and usually infect the lungs, but they can also infect other parts of the body. Although TB is infectious, it does not spread easily. You usually have to spend a lot of time in contact with someone who is contagious to get it.
How is tuberculosis spread?
TB can be spread when a person with active TB disease releases germs into the air by coughing, sneezing, talking, singing, or even laughing. Only people with active lung infections are contagious. Most people who inhale TB bacteria can fight the bacteria and keep it from growing. The bacteria become inactive in these individuals, causing a latent tuberculosis infection.
Up to 13 million people in the US have latent TB. Although the bacteria are inactive, they still remain alive in the body and can become active later. Some people can have a latent TB infection throughout their lives, without becoming active and becoming TB disease.
However, TB can be triggered if your immune system becomes weak and cannot stop the growth of the bacteria. This is when the latent TB infection becomes active TB. Many researchers are working on treatments to prevent this from happening.
What are the signs and symptoms of tuberculosis?
People with inactive TB have no symptoms. However, they may have a positive skin reaction test or blood test. Those with active TB may display any of the following symptoms:
- Bad cough (lasting more than two weeks).
- Chest pain.
- Coughing up blood or sputum (mucus).
- Fatigue or weakness.
- loss of appetite
- Shaking chills.
- Night sweats.
What types of tests are used to diagnose tuberculosis?
There are two types of TB screening tests: the Mantoux tuberculin skin test (TST) and the blood test, called the interferon-gamma release assay (IGRA). For TST, a healthcare provider will inject a small amount of a substance called purified protein derivative (PPD) under the skin of your forearm.
After two to three days, you should return to your healthcare provider, who will examine the injection site. For IGRA, a healthcare provider will draw blood and send the sample to the laboratory. Other tests to determine if an infection is active or if your lungs are infected include:
- Laboratory tests on sputum and lung fluid.
- Chest X-ray.
- Computed tomography (CT) scans.
How is tuberculosis treated?
TB infection and disease are treated with these medicines:
- Isoniazid (Hyzyd®).
- Rifampicin (Rifadin®).
- Ethambutol (Myambutol®).
- Pyrazinamide (Zinamide®).
- Rifapentine (Priftin®).
You must take all the medicines your provider prescribes, or all the bacteria will not be killed. You will need to take these medications for as long as prescribed, sometimes up to nine months. Some forms of TB have become resistant to drugs. It is very important and likely that your provider will use more than one medicine to treat your TB. It is very important to finish all of your recipes.
Complications/side effects of treatment
Some people have side effects from the medicines used to treat TB which may include:
- Skin rashes and other reactions.
- Nausea and upset stomach.
- Skin itch.
- Yellow skin or eyes (jaundice).
- dark urine
Talk to your provider about side effects, as some may mean you are experiencing liver damage.
What can you do to prevent the spread of tuberculosis?
You usually have to be around someone with active TB for a long time before you get infected. It is helpful to follow infection prevention guidelines such as:
- Wash hands thoroughly and frequently.
- Cough into your elbow or cover your mouth when coughing.
- Avoiding close contact with other people.
- Make sure you take all your medicines correctly.
- Not return to work or school until cleared by your health care provider.
In the hospital, the most important measures to stop the spread of TB are to have adequate ventilation and use the correct types of personal protective equipment.
Is there a vaccine to prevent tuberculosis?
Some countries (but not the US) use a TB vaccine called Bacillus Calmette-Guerin (BCG). The vaccine is mainly given to children in countries with high TB rates to prevent meningitis and a severe form of TB called miliary tuberculosis. The vaccine can make TB skin tests less accurate.