While TB is easily passed from person to person under certain circumstances, it generally doesn’t spread through casual contact. How Can You Get TB? TB is a highly contagious bacterial infection that can quickly spread if not caught, isolated, and treated early. Tuberculosis is an airborne disease, and can be caught by breathing in the air that an infected person has contaminated through:
BreathingCoughingTalkingSingingSneezing
TB germs must be forced into the air, and to get a tuberculosis infection you must breathe in those germs. But even if you’ve been around an infected person, or breathed in the bacteria they expelled into the air, you still have a chance at escaping TB — not everyone who breathes in the bacteria will develop tuberculosis. Ways You Won’t Get TB If you can get tuberculosis infection by breathing in the air where someone spoke, it should be pretty easy to catch the illness by just touching someone who has TB, right? Actually, no. You can’t get TB by touching an infected person. Tuberculosis germs don’t stick to clothing or skin; they hang out in the air. You also can’t get TB by:
Giving an infected person a hug or a kissUsing the same toothbrushEating or drinking after an infected personShaking handsSharing clothing, a bed, or towelsUsing the same toilet as an infected person
Who’s Most Contagious? A person who has been infected with tuberculosis may not yet show any symptoms of TB, and may have no idea that they’re sick — and they’re also are not contagious at this stage. If active tuberculosis disease does develop, and symptoms appear — such as persistent coughing, coughing up blood, breathing problems, or flu-like symptoms — the disease is contagious. Even before a TB diagnosis, people can unwittingly transmit tuberculosis to others. People with symptomatic TB are contagious until they have taken their TB medications for at least two weeks. After that point, treatment must continue for months, but the infection is no longer contagious. Anyone who has been in contact with someone with TB should have a tuberculosis test (also called a PPD test) immediately to find out whether they have the illness, and if they are capable of spreading it to other people. Who Is Most Susceptible to Tuberculosis? Being around a person infected with TB, or even breathing in the air contaminated with tuberculosis germs, doesn’t mean that you’ll definitely get TB. However, certain people are more susceptible to the disease than others. People with healthy immune systems are better able to defend themselves against the progression of tuberculosis infection into active TB disease, while those with weakened immune systems — for instance, people with HIV — are much more susceptible to actually developing active tuberculosis disease. The longer you spend with someone who has contagious TB, the greater the likelihood that you’ll catch the illness. But even if you are infected with tuberculosis, you may still never get sick. Less than 10 percent of people who have been infected with the tuberculosis bacteria go on to develop active tuberculosis disease. If you have tuberculosis, it’s very important to take all medications exactly as prescribed and avoid contact with others until you are no longer contagious. And people who are most susceptible to TB should take care to avoid those infected with the disease.
