San Diego County health officials issued a stark warning Monday: tuberculosis is back, and the region is now one of the worst-affected areas in the country.

County data shows San Diego recorded 265 active TB cases in 2025 — the highest total in more than a decade and the fifth consecutive year of increases. The county infection rate reached 8 cases per 100,000 residents last year, nearly 50% higher than the California state average of 5.4 per 100,000 and more than double the national rate of 3.1 per 100,000.

At a briefing Monday at Waterfront Park — ahead of World Tuberculosis Day on March 24 — County Supervisor Paloma Aguirre was joined by Public Health Officer Dr. Sayone Thihalolipavan and TB Medical Director Dr. Jeffrey Percak. Health leaders cautioned that active cases are just the tip of a larger problem: an estimated 175,000 San Diegans are living with latent TB infection, meaning the bacteria lies dormant in their bodies and can become active and contagious if their immune systems weaken.

For East County residents, the warning is relevant. TB is an airborne disease spread when an infected person coughs, speaks, or sings, making crowded spaces, schools, and workplaces potential transmission points. Key symptoms include a persistent cough, fever, night sweats, and unexplained weight loss. Statewide data show that 14% of people diagnosed with active TB in California do not survive treatment — a stark reminder of the disease's severity.

County officials attributed the surge partly to San Diego being a major global transit hub and refugee resettlement destination, putting it in direct contact with populations from regions where TB remains endemic. The Tuberculosis Prevention and Care Branch is expanding through the TB Elimination Initiative — active since 2020 with more than 25 community healthcare organizations — under California law requiring providers to report suspected cases within one working day.

The County Administration Center will be illuminated in red Tuesday night in solidarity with World TB Day landmarks worldwide. Residents with potential exposure or risk factors — including diabetes, weakened immunity, or recent incarceration — are urged to contact a healthcare provider or call the county TB program at (619) 692-5565.