Where TB Hits Hardest

California’s tuberculosis (TB) incidence has dropped dramatically since the 1930s. It has steadily declined over the past decade but now has stopped, according to the California Department of Public Health. At 5.5 cases per 100,000 people, the rate is nearly double the national incidence rate. The disease overwhelmingly affects people who come to the U.S. from countries where it is more common, including Mexico, the Philippines, Vietnam, China and India.

There were 2,137 new TB cases reported in California in 2015, three more than were reported in 2014.

In addition, an estimated 2.4 million residents have latent TB infections. People with latent TB infection do not feel sick and do not have any symptoms, according to the Centers for Disease Control and Prevention. They are infected with the Mycobacterium tuberculosis, but do not have active disease and cannot spread the disease to others.

An estimated 7 percent were imported from outside the United States, 13 percent resulted from recent transmission and 80 percent were due to reactivation of a latent infection, typically among people who come from outside California. Statewide, the TB rate among people born outside the U.S. was 16.5 per 100,000 while the rate among U.S.-born persons was 1.4 per 100,000.

Imperial County reported 16.8 cases of active TB per 100,000 people — the highest rate in the state — many of them among “binational” migrants. Of reporting counties, Sonoma County reported the lowest rate with 1.8 cases per 100,000.

CDPH Director and State Health Officer Dr. Karen Smith recently urged health care providers to adopt new recommendations from the U.S. Preventive Services Task Force calling for adults 18 years of age or older who are at increased risk of TB to be screened for the disease.

“If universally adopted,” Smith said, the recommendations “can help us eliminate TB in California in the next few decades.”