What is the difference between latent TB infection and active TB disease?
When the TB germs get into the body, they usually go “to sleep.” This is called “latent TB infection” or “LTBI.” “Sleeping” TB germs do not hurt your body or make you sick. LTBI can last for many years. The Mantoux TB skin test can tell if there are TB germs in your body. “Active TB disease” is when the TB germs “wake up” and start to grow and hurt your body. People with active TB disease can get very sick. TB symptoms include a cough that doesn’t go away, losing weight, poor appetite, sweating at night, fever, and pain in your chest. If the TB is in their lungs, it can spread to other people. About 10% of people with LTBI develop active TB disease. If you have other health problems, this risk may be higher.
