What Is TB Disease?
TB bacteria become active if the immune system can’t stop them from growing. The active bacteria begin to multiply in the body and cause TB disease. Some people develop TB disease soon after becoming infected, before their immune system can fight the TB bacteria. Other people may get sick later, when their immune system becomes weak for some reason.
Some people develop TB disease soon after becoming infected when TB bacteria begin to multiply rapidly, before their immune system can fight back. Other people may get sick later, when their immune system becomes weak for some reason. TB in other parts of the body, such as the kidney or spine, is usually not infectious. Babies and young children often have weak immune systems. People infected with HIV have very weak immune systems.
