Tuberculosis: Common Questions and Answers

Approximately 10 million people worldwide were infected with tuberculosis (TB) in 2019, resulting in 1.4 million deaths. In the United States that same year, there were nearly 9,000 reported cases of TB disease and up to 13 million people were living with latent TB infection (LTBI), which is an asymptomatic, noncommunicable infection caused by Mycobacterium tuberculosis. Without treatment, LTBI will progress to active TB disease in approximately 5% to 10% of affected people. Individuals with symptoms of TB disease warrant testing. The U.S. Preventive Services Task Force recommends testing individuals at increased risk of LTBI with an interferon-gamma release assay or tuberculin skin testing. Because the incidence of LTBI in health care professionals is similar to that of the general population, periodic retesting is not recommended. After a positive test result, chest radiography should be performed and, in patients with suspected pulmonary TB disease, sputum collected for diagnosis. Both suspected and confirmed cases of LTBI and TB disease must be reported to local or state health departments. Preferred treatment regimens for LTBI include isoniazid in combination with rifapentine or rifampin, or rifampin alone for a duration of three and four months, respectively. Treatment of drug-susceptible TB disease includes an eight-week intensive phase with four drugs (isoniazid, rifampin, pyrazinamide, and ethambutol), followed by a continuation phase lasting 18 weeks or more, with two drugs based on susceptibility testing results. Consultation with a TB expert is necessary if there is suspicion or confirmation of drug-resistant TB.