Persons at risk for TB include anyone who has ever had contact with a person with infectious TB. Some persons are considered to be at high risk for TB disease because they belong to groups in which the prevalence of TB infection is higher than it is in the general population. These groups include foreign-born persons from areas with a high prevalence of TB; residents and employees of long-term institutional settings (such as nursing homes and correctional facilities); and medically underserved populations, including the poor, the homeless, high risk racial and ethnic minority groups, and injecting drug users (IDUs). Other persons are at high risk for developing active TB disease if they become infected with Mycobacterium tuberculosis. They include immunocompromised persons (especially those with HIV infection), persons with other medical risk factors (such as diabetes, end-stage renal disease, and being 10 percent or more below ideal body weight), and IDUs.

HIV infection is one of the strongest known risk factors associated with the progression from TB infection to active TB disease. Studies suggest that the risk of developing TB disease is 7% to 10% each year for persons who are infected with both M. tuberculosis and HIV, whereas it is 10% over a lifetime for persons infected only with M. tuberculosis.