The Kansas Department of Health and Environment (KDHE) is reporting a tuberculosis (TB) outbreak in the greater Kansas City area centering around Wyandotte County, which is where the city is located, and neighboring Johnson County.¹

As of the most recent update (January 24), the number of active cases being reported are 60 cases in Wyandotte County, and 7 cases in Johnson County. The number of latent infections since 2024 is 77 cases in Wyandotte County, and 2 cases in Johnson County.¹

Officials are saying this is the largest TB outbreak in the US since records were kept, going back several decades to at least the 1950s, when the Centers for Disease Control and Prevention (CDC) began its monitoring and reporting of TB cases.

What is Being Done in Kansas

Following standard practice in infectious disease investigations, KDHE said local health departments are working with each patient to identify possible close contacts and conduct TB testing at no cost. Patients who test positive will be further screened to determine if they have active TB disease or latent TB infection, which will help determine the best treatment.¹

Treatment will be provided through the patient's local health department, and it will be provided for free if the person is uninsured or the treatment isn’t covered by health insurance. Treatment will be provided through the patient's local health department and will be provided for free if the person is uninsured or the treatment isn’t covered by health insurance.¹

Health department staff will remain in touch with patients throughout treatment to help them stay on course and address any questions or concerns they may have.¹

Latent Vs Active TB infection

For the uninitiated, people with latent TB Infection (LTBI) are infected with the bacteria, mycobacterium tuberculosis, which causes TB, but do not have the disease. The bacterium can become active and develop into an active TB disease.² In active infection, the body’s immune system cannot fight off the bacterium. People will feel the effects, can spread the bacteria, and can die if not treated.³

In terms of transmissibility, TB is spread through the air from 1 person to another. The TB pathogen can be released from a person with active TB when he or she coughs, speaks, or sings.³

US Incidence Rates Vs Internationally

The Centers for Disease Control and Prevention (CDC) estimates that up to 13 million people in the United States have LTBI.³ While not everyone with LTBI will develop TB disease, without treatment about 5%–10% of infected people will develop active TB disease over their lifetimes. ²

The incidence rate of TB is much higher in developing countries than here in the United States. In the US, the TB rate declined slightly (-2.3%) from 2016 to 2017 with approximately 2.8 cases per 100,000 persons.⁴

According to the World Health Organization, in 2023, an estimated 10.8 million people became infected with TB worldwide, including 6.0 million men, 3.6 million women and 1.3 million children.⁵ Worldwide, up to 25% of the population might be infected with LTBI.⁶

References
1.Tuberculosis Outbreaks. KDHE press statement. Accessed January 28, 2025.
https://www.kdhe.ks.gov/2242/Tuberculosis-Outbreaks
2. Clinical Overview of Latent Tuberculosis Infection. May 8, 2024. Accessed January 28, 2025.
https://www.cdc.gov/tb/hcp/clinical-overview/latent-tuberculosis-infection.html
3.About Tuberculosis. CDC. January 17, 2025. Accessed January 28, 2025.
https://www.cdc.gov/tb/about/index.html
4. Stewart RJ, Tsang CA, Pratt RH, Price SF, Langer AJ. Tuberculosis — United States, 2017. MMWR Morb Mortal Wkly Rep 2018;67:317–323. DOI: http://dx.doi.org/10.15585/mmwr.mm6711a2
5.Tuberculosis. WHO. Accessed January 28, 2025. https://www.who.int/news-room/fact-sheets/detail/tuberculosis
6. Kiazyk S, Ball TB. Latent tuberculosis infection: An overview. Can Commun Dis Rep. 2017;43(3-4):62-66. Published 2017 Mar 2. doi:10.14745/ccdr.v43i34a01