Tuberculosis (TB) is a contagious infection that usually attacks your lungs. It can also spread to other parts of your body, like your brain and spine. A type of bacteria called Mycobacterium tuberculosis causes it.
In the 20th century, TB was a leading cause of death in the United States. Today, most cases are cured with antibiotics. But it takes a long time. You must take medications for at least 6 to 9 months.
Tuberculosis is caused by bacteria that spread through the air, just like a cold or the flu. You can get TB only if you come into contact with people who have it.
A TB infection doesn’t always mean you’ll get sick. There are two forms of the disease:
Latent TB. You have the germs in your body, but your immune system keeps them from spreading. You don’t have any symptoms, and you’re not contagious. But the infection is still alive and can one day become active. If you’re at high risk for re-activation — for instance, if you have HIV, you had an infection in the past 2 years, your chest X-ray is unusual, or your immune system is weakened — your doctor will give you medications to prevent active TB.
Active TB. The germs multiply and make you sick. You can spread the disease to others. Ninety percent of active cases in adults come from a latent TB infection.
A latent or active TB infection can also be drug-resistant, meaning certain medications don’t work against the bacteria.
Latent TB doesn’t have symptoms. A skin or blood test can tell if you have it.
Signs of active TB disease include:
If you have any of these symptoms, see your doctor to get tested. Get medical help right away if you have chest pain.
You could be more likely to get TB if:
A healthy immune system fights the TB bacteria. But you might not be able to fend off active TB disease if you have:
When someone who has TB coughs, sneezes, talks, laughs, or sings, they release tiny droplets that contain the germs. If you breathe in these germs, you can get it.
TB is NOT spread by
TB isn’t easy to catch. You usually must spend a long time around someone who has a lot of the bacteria in their lungs. You’re most likely to catch it from co-workers, friends, and family members.
Tuberculosis germs don’t thrive on surfaces. You can’t get it from shaking hands with someone who has it or by sharing their food or drink.
There are two common tests for tuberculosis:
Those tests don’t tell you if your infection is latent or active. If you get a positive skin or blood test, your doctor will learn which type you have with:
If you have latent TB, your doctor will give you medication to kill the bacteria so the infection doesn’t become active. You might get isoniazid, rifapentine, or rifampin, either alone or combined. You’ll have to take the drugs for up to 9 months. If you see any signs of active TB, call your doctor right away.
A combination of medicines also treats active TB. The most common are ethambutol, isoniazid, pyrazinamide, and rifampin. You’ll take them for 6 to 12 months.
If you have drug-resistant TB, your doctor might give you one or more different medicines. You may have to take them for much longer, up to 30 months, and they can cause more side effects.
Whatever kind of infection you have, it’s important to finish taking all of your medications, even when you feel better. If you quit too soon, the bacteria can become resistant to the drugs.
Common isoniazid side effects include:
Ethambutol side effects may include:
Some pyrazinamide side effects include:
Common rifampin side effects include:
Tuberculosis infection can cause complications such as:
Children in countries where TB is common often get the BCG vaccine. It doesn’t always protect against infection. Doctors recommend it only for children living with someone who has an active TB infection with a very drug-resistant strain or who can’t take antibiotics. Other vaccines are being developed and tested.