year high in Calif. as outbreaks increase

Key Points:

• California is experiencing significantly higher tuberculosis (TB) rates than the national average, with 2,150 cases reported in 2025, marking a 12-year high and a rate of 5.4 per 100,000 compared to the U.S. average of 3 per 100,000.
• The CDC reported an increase in large TB outbreaks nationwide, rising from 24 outbreaks between 2014-2016 to 50 between 2017-2023, with 79% of affected individuals in these outbreaks being U.S.-born and often linked to substance abuse and close social or family networks.
• TB remains a serious health threat despite being treatable with antibiotics, with about 13% of TB patients in California dying in 2023, especially among those with compromised immune systems or risk factors such as homelessness, substance use, incarceration history, and malnutrition.
• TB can exist in latent or active forms; latent TB is symptom-free and non-contagious but can activate and spread, as demonstrated by a recent outbreak at a San Francisco high school that resulted in multiple active and latent cases.
• Experts emphasize the contagiousness of TB and the importance of early detection and treatment to prevent outbreaks, noting that despite modern medicine, TB continues to persist globally due to challenges in controlling latent infections and social risk factors.