What do we know about the tuberculosis (TB) outbreak in Kansas?
The Kansas Department of Health and Environment is reporting the largest TB outbreak in recent U.S. history. As of February 21, 2025, 67 active TB and 80 latent TB cases have been reported. The majority of both active and latent cases reside in Wyandotte county, which includes Kansas City. Local health departments are working with patients to identify close contacts and conduct testing. Healthcare providers in and around Kansas City are encouraged to consider TB in patients with fever, fatigue, weight loss, night sweats, cough, and/or hemoptysis.
What is the difference between active TB and latent TB?
Active TB refers to the clinical syndrome (disease) caused by Mycobacterium tuberculosis infection. Active TB is commonly pulmonary (a disease of the respiratory system) but can also manifest in other body sites. In contrast, latent TB is caused by Mycobacterium tuberculosis infection without clinical or radiological findings. Latent TB can be diagnosed through skin or blood testing, which detects an immune response to the bacteria. Because latent TB can progress to active disease, it is also treated. Unlike active TB, latent TB is not considered infectious and does not require isolation. However, active pulmonary TB is considered contagious until properly treated.
When should you be concerned about a diagnosis of TB?
Tuberculosis is not always easy to diagnose even when it is active, and the only way to diagnose latent TB is to test people who may have been exposed to the active form of the disease. Although TB can affect almost any part of the body, the most common location for active tuberculosis is the lungs. Cavitary lesions (which look like gradually expanding hollow balls) in the upper parts of the lung are sometimes seen in people who previously had tuberculosis and in whom the disease has reactivated. But most people recently exposed to tuberculosis will either not develop symptoms (latent TB) or will develop a cough and fever and the chest x-ray will look like pneumonia. Sometimes the only clue to tuberculosis is how long a cough has persisted, which can mean that contagious people can often go weeks or months without being diagnosed.
What is the treatment for active and latent TB?
Mycobacterium tuberculosis is not an easy bacterium to get rid of, and treatment often involves multiple antibiotics taken daily over many months, plus repeated testing to verify treatment success. Some patients do not complete this lengthy therapy, which allows the bacteria to develop drug resistance, making it even more difficult to cure. Shorter antibiotic regimens have been tested and may be considered for some otherwise healthy patients. Regimens for the treatment of active TB can be found in DynaMedex: Pulmonary Tuberculosis.
Since people with latent TB are at risk for developing active disease, they should be treated with preventative therapy. Preventative TB therapy may also be offered to high-risk close contacts such as children and persons with immunocompromise. Various regimens for preventative TB therapy may be considered and can be found in DynaMedex: Latent Tuberculosis Infection (LTBI).
Some patients have TB that is resistant to first-line antibiotics. These infections can be isoniazid-resistant, multidrug-resistant (resistance to both isoniazid and rifampin), or extensively drug-resistant (resistance to isoniazid, rifampin, plus a fluoroquinolone and at least bedaquiline, linezolid, or one injectable second-line drug). The more drug resistant, the greater chance of treatment failure and mortality.
Is there a vaccine for TB?
There is a live-attenuated TB vaccine called Bacille Calmette-Guerin (BCG) that was derived from a related bacterium, Mycobacterium bovis. BCG is only widely used in regions with a high incidence of TB and/or leprosy. Because BCG is a live vaccine, M. bovis can replicate and cause adverse reactions in some vaccinated individuals such as abscesses, suppurative adenitis, and disseminated infection in immunocompromised persons. Overall efficacy of BCG is also modest and seems to work best in children. So, the benefits of vaccination with BCG only outweigh the risks for infants who are at risk for contracting TB.
What is the risk of TB for the general public, especially those living in an outbreak area like Kansas City?
The risk to the general public, even those residing in the outbreak area of Wyandotte county, Kansas, remains low. Despite the recognition of TB in January 2025, this outbreak has been going on for months and possibly longer. Contact tracing and screening is ongoing to identify new cases and contain further spread. No new active cases have been identified over the past couple of weeks. As long as people follow instructions from their doctors and public health officials, this outbreak may be contained.
