The County is raising awareness about tuberculosis (TB), a preventable and curable disease, in recognition of World Tuberculosis Day on March 24.
World Tuberculosis Day marks Dr. Robert Koch’s 1882 discovery of the bacteria that causes TB, a breakthrough that made diagnosis and treatment possible for a disease that once killed one in seven people worldwide.
Today, tuberculosis remains the world’s leading infectious disease killer, taking more than 1.2 million lives each year. An estimated one-quarter of the global population has a TB infection.
Rising TB Diagnoses in San Diego County
Local cases continue to climb. In 2025, the County recorded 265 active TB diagnoses, marking the fifth consecutive year of increases and the highest total in more than a decade. San Diego County’s rate of eight cases per 100,000 residents remains higher than California’s rate of 5.4 and the national rate of 3.1.
Despite being preventable, active TB still causes significant illness and death. Fourteen percent of people diagnosed with TB in 2023 did not survive treatment, and one in six people with TB die within five years. Young children, especially those under the age of five, are at greater risk of severe illness.
TB spreads through the air when a person with active TB disease coughs, speaks, sings or breathes out the bacteria. People can also become infected by consuming unpasteurized dairy products from cows infected with M. bovis. While TB most often affects the lungs, it can impact other parts of the body.
Symptoms may include a persistent cough, fever, night sweats and unexplained weight loss. Factors such as limited access to affordable housing, education, employment and health care, as well as incarceration or experiencing homelessness, increase the risk for TB. Health conditions like diabetes, smoking and weakened immune systems increase the chance that TB infection progresses to active disease.
Working Together to Prevent TB
The most effective way to prevent active TB disease is to treat latent TB infection (LTBI) before a person can become sick.
An estimated 175,000 residents have latent TB infection, meaning they have the TB germ but do not feel sick or have symptoms. Yet only 25 percent know they are infected and just 15 percent have received treatment.
To strengthen local prevention and treatment, the County launched a TB Elimination Initiative in 2020. It is a public-private partnership bringing together healthcare organizations, health plans, community-based organizations, advocacy groups, schools and others to improve TB risk assessment, testing and treatment.
Residents who believe they may have been exposed to TB or who have risk factors should talk with their health care provider or visit the County TB Control Program website for TB testing and treatment information.
Commemorating World TB Day
On Tuesday, March 24, the County Administration Center will be illuminated in red to mark World Tuberculosis Day, joining landmarks around the world in raising awareness of this preventable disease.
