What's Happening?
California is experiencing a significant surge in Tuberculosis (TB) cases, with the state reporting over 2,150 cases in 2025, marking the highest number in 12 years. This figure is nearly double the national incidence rate, with California reporting 5.4
cases per 100,000 people compared to the national average of three per 100,000. The U.S. Centers for Disease Control and Prevention (CDC) has identified 50 large TB outbreaks in the U.S. between 2017 and 2023, with 79% of these cases involving U.S.-born individuals. The outbreaks are primarily linked to family or social networks and congregate settings. Factors contributing to the rise in TB cases include housing insecurity, substance use, immigration, and incarceration, which are prevalent in California.
Why It's Important?
The increase in TB cases in California highlights significant public health challenges, particularly in addressing diseases associated with poverty and social determinants of health. The state's higher rates of housing insecurity and substance use exacerbate the spread of TB, a disease that remains highly contagious and potentially fatal despite being treatable. The situation underscores the need for robust public health strategies, including national genomic surveillance and targeted state and local TB programs. The rising TB rates also reflect broader socio-economic disparities, which could lead to further public health crises if not addressed.
What's Next?
Efforts to control and prevent TB outbreaks will require overcoming barriers to diagnosis and treatment, particularly among populations affected by homelessness and substance use. Public health officials may need to implement more comprehensive testing and treatment programs, especially in high-risk areas. Continued monitoring and research into the social determinants of health that contribute to TB outbreaks will be crucial in developing effective prevention strategies.
