A rising number of tuberculosis cases in the Bay Area should make everyone think twice when someone around them coughs without covering their mouth.
Last year, San Francisco, San Mateo, Santa Clara and Alameda counties saw some of the steepest inclines of infections in the state, according to a recent study. The City saw a more than 19 percent increase in cases since 2006, Santa Clara County was up nearly 6 percent and San Mateo and Alameda counties rose 11.5 percent and 5.7 percent, respectively.
The upward trend stands in stark contrast with the national rate, which was at its lowest point ever last year at 13,293 cases, a more than 4 percent drop, according to a CDC report released Thursday. Health experts say most cases found in the U.S. came from foreign-born carriers, which makes the Bay Area one of the most susceptible regions to the spread of the disease because of its three international airports.
"Since international travel today is almost as common as a Bay Bridge commute, and San Francisco is a major international port of entry to the U.S., much of the TB in the Bay Area migrates here from TB-endemic countries," said Dr. Masae Kawamura, director of TB control in San Francisco.
About 2 billion people worldwide are infected with tuberculosis, which mostly attacks the lungs, health officials say. Most people have a latent form that doesn’t spread or cause sickness. But some of those cases can become active. People traveling into the Bay Area with an inactive form could become active while they’re here and risk infecting others, officials said.
"TB is an odd germ that can be dormant in your body," said Margo Sidener, president and CEO of Breathe California. "You can test not having an active form of the disease and be allowed to immigrate, but then you can later break out and spread to others."
What is most alarming, Kawamura said, is the global rise of a deadly, multidrug-resistant strain of tuberculosis. The infection becomes resistant when patients don’t finish a full treatment of medication. Drug-resistant TB, like the regular form, can be transmitted through the air to a noninfected person.
"And that’s very scary," Sidener said. "Many countries don’t have the capacity to treat TB. They begin the long course of treatment, which could take up to six months, but don’t complete it. The disease becomes resistant and morphs into a super bacteria."
In honor of World Tuberculosis Day today, tuberculosis experts from around the Bay Area will gather at the San Francisco International Airport to address these concerns.
"It is crucial that we retain the tools to rapidly diagnose less curable multi-drug-resistant TB," Kawamura said.