Tuberculosis (TB), a bacterial infection found most often in the lungs, is one of the most deadly diseases in the world.
More than 1.5 million people died worldwide from TB in 2018, according to the World Health Organization. That ranks as the No. 1 infection-related cause of death in the world and among the top 10 most deadly diseases.
The U.S. has seen a drop in TB cases over the years, with the Centers for Disease Control and Prevention reporting just over 9,000 cases in 2018. That’s a rate of about 2.8 cases per 100,000 people.
Tuberculosis is both preventable and curable. But it also is difficult to diagnose, contagious, and deadly.
What Is Tuberculosis?
Tuberculosis is an infection, caused by slow-growing bacteria called Mycobacterium tuberculosis. These bacteria grow best in parts of the body with high amounts of blood and oxygen, which is why TB usually affects the lungs. However, they also can form in other parts of the body – including the brain, the kidneys, or the spine.
There are two types of TB:
- Latent TB: You have been exposed to tuberculosis, but you are not sick with it. This is not contagious. However, about 10 percent of people who have latent TB will develop active TB at some time in their life. This can be prevented with antibiotics.
- Active TB: This is when you have an active infection. You may have symptoms such as a cough, night sweats, or weight loss. If you have active TB, this can be spread to other people.
If you have been exposed to someone with active TB, you should be tested to see if you have become infected.
In the U.S., cases of TB have dropped steadily since the mid-1900s, with 2018 seeing the lowest total yet. Worldwide, about 10 million people were diagnosed with TB in 2018. Eight countries accounted for two-thirds of the cases, according to the WHO: India, China, Indonesia, the Philippines, Pakistan, Nigeria, Bangladesh, and South Africa.
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How Does Tuberculosis Spread?
Pulmonary tuberculosis – TB in the lungs – spreads through the air. When someone with pulmonary TB breathes, coughs, laughs, sneezes, or spits, the germs can get into the air. Someone else can be infected if they breathe in any of those germs. TB spreads most easily in closed spaces over a long period of time – for instance, within a family home or a work environment.
TB found in other parts of the body does not spread easily.
Who Is at Risk of Tuberculosis?
People most at risk of getting infected with tuberculosis include:
- People who have been in close contact with someone who has active TB.
- People who live in close spaces with people at high risk for TB
- People who live or spent time in countries where untreated TB is common
- Health care workers who are in contact with people infected with active TB, especially if proper infection protocols aren’t followed
- People who have HIV or another disease that weakens the immune system
- People who abuse drugs or alcohol
- People with poor access to health care
What Are the Symptoms of Tuberculosis?
Latent TB does not carry symptoms. Active TB does, and symptoms include:
- A bad cough that lasts for more than two weeks
- Coughing up thick, cloudy, and sometimes bloody mucus (sputum)
- Weight loss
- Night sweats
- Rapid heartbeat
- Shortness of breath
- Chest pain
- Neck swelling (if lymph nodes are infected)
If you have active TB outside your lungs, your symptoms will depend on the part of body infected.
How Is Tuberculosis Diagnosed?
Doctors usually can diagnose latent TB through a tuberculin skin test. A doctor or nurse will inject TB antigens under the skin. A red bump will appear at the injection site within two days if you have the bacteria. Doctors also can use a blood test.
For pulmonary TB, doctors can test a sample of mucus from the lungs for TB bacteria, or they can perform a chest X-ray.
For TB outside the lungs, doctors can biopsy a tissue sample for diagnosis. They also can use CT or MRI scans.
How Is Tuberculosis Treated?
- Active TB: The main treatment for active TB is antibiotics. Antibiotic treatment generally lasts for at least six months, with an additional two to three months possible if the TB remains. Doctors usually use a combination of four antibiotics:
- isoniazid (INH)
- rifampin (RIF)
- ethambutol (EMB)
- pyrazinamide (PZA).
- Latent TB: Antibiotics can also be used to treat latent TB, with treatment lasting anywhere from three to nine months.
Specialized TB treatment is available for children, pregnant women, and people with HIV.
If you have TB, it’s crucial to follow the full course of treatment. If you don’t take the proper dose, or you stop treatment too soon, the treatment may not work. You also could have to start again. The infection also could become worse or become resistant to antibiotics.
The full course of treatment can cure TB. If left untreated, the disease can cause lung damage or death. It also can spread to other people.
Can I Prevent Tuberculosis?
There is a vaccine for tuberculosis (bacille Calmette-Guerin, or BCG). It is not commonly given in the United States because TB is rare in the U.S. and because the vaccine is generally not as effective in adults.
Because TB is spread through the air, much of prevention comes down to taking proper precautions:
- Don’t spend a large amount of time in enclosed rooms with people who have active TB.
- Use face masks or other protection if you’re a health care worker or you work in a facility that cares for people with TB.
- Cover your mouth and nose with a tissue when you sneeze, or sneeze into your upper sleeve.
- Dispose of used tissues in the trash.
- Wash your hands after coughing or sneezing.
- Don’t go to work, school, or other places where you can infect people.
- Sleep in a bedroom by yourself to avoid infecting others in your home.
- Open the windows, if possible, in rooms where you’re spending a lot of time. This can rid the air of TB bacteria.
About Infectious Diseases
If you have a disease caused by bacteria, fungi, parasite, or virus, the UPMC Center for Care of Infectious Diseases can help. Our team of experts is specially trained in the prevention and treatment of infectious diseases, including of HIV-AIDs, postsurgical and transplant infections, illnesses caused by international travel, and more. We research infectious diseases and participate in clinical trials to learn more and develop better treatment and prevention methods. Visit our website to find an expert near you.