Health officials are raising the alarm over a large and ongoing tuberculosis (TB) outbreak in Kansas.
According to data from the Kansas Department of Health and Environment (KDHE), the cases have all occurred in Wyandotte County and Johnson County, both part of the greater Kansas City metro area. So far, 67 “active” TB infections and 79 “latent,” or “inactive” infections have been linked to the outbreak.
In latent TB, the immune system suppresses the bacteria — called Mycobacterium tuberculosis — behind the infection. Although they’re inside the body, the bacteria don’t cause any symptoms and can’t spread to additional people. While many people with latent TB never develop active TB, about 5% to 10% do. This is more likely to happen to people with malnourishment, a history of smoking or tobacco use, or who have weakened immune systems, due to diabetes, immune-suppressing drugs or infections like HIV/AIDS.
“This outbreak is still ongoing, which means that there could be more cases,” Jill Bronaugh, the KDHE communications director, told Live Science by email. The earliest cases linked to the ongoing outbreak took place in January 2024. Two deaths in 2024 were connected to the outbreak.
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Bronaugh added that the Kansas TB outbreak is the “largest documented outbreak in U.S. history,” since the 1950s when formal recordkeeping began. That recordkeeping started after the first effective treatments for TB were developed in the 1940s and 1950s, when improvements in housing and nutrition had already been helping drive down cases nationwide.
The annual rate of active TB cases and TB-related deaths currently remains low in the U.S., especially compared to countries where the disease is widespread. However, cases have been on the rise in recent years. In 2023, the Centers for Disease Control and Prevention (CDC) recorded over 9,600 active TB cases nationwide, or about 2.9 per 100,000 people. That’s about 15% more than reported in 2022, and the most reported since 2013.
Notably, in 2021, Kansas experienced an outbreak of multidrug-resistant TB that affected just over a dozen people. These infections are trickier to treat because the bacteria show resistance to common first-line antibiotics used to cure TB.
Live Science asked KDHE if any of the cases in the current outbreak are drug-resistant but did not receive a response by the time of publication.
The health department is currently working with infected patients to identify close contacts who may have been exposed. Anyone who tests positive will be further examined to see if they have active or latent TB, since that dictates which treatment they receive. Although there is a vaccine for TB, it is generally not used in the U.S. because the risk of infection is so low, according to the CDC.
Treatments for TB typically involve taking multiple antibiotics for months at a time. Local health departments will provide these treatments to the patients in Kansas, and they will be free for those who are underinsured or uninsured, KGHE said.
TB-causing bacteria spread through the air, and are released when a person with active TB in their lungs speaks, sings or coughs. Once in the body, the bacteria can also spread beyond the lungs to other organs, such as the kidneys, spinal cord or brain. The symptoms a person experiences depend on which body parts are infected, but active TB in the lungs causes cough (including coughing up blood), chest pain, weakness, weight loss and fever, for example.
“While there is a very low risk of infection to the general public in these communities, KDHE is working to ensure that patients are receiving appropriate treatment, which will limit the ability to spread this disease and prevent additional cases from occurring,” Bronaugh told Live Science. “We are working with and following the guidance of the CDC.”
This article is for informational purposes only and is not meant to offer medical advice.
