Tuberculosis cases rising in California, and state officials are sounding the alarm

"We have a lot of people who travel, and also have family members who come from other countries with higher rates of TB," Dr. Regina Chinsio-Kwong, Orange County's health officer, said.

Cities in Orange County with TB case rates higher than the overall county rate are Laguna Hills, Westminster, Garden Grove, Buena Park, Santa Ana, Fountain Valley, Anaheim, Costa Mesa and Lake Forest, according to county data.

Those at highest risk in Orange County are people born outside the U.S., Asian Americans, males, and seniors age 65 and up. Having diabetes, HIV or smoking cigarettes increases the risk of having latent TB develop into full-blown TB, Chinsio-Kwong said.

With "latent TB, when someone's immune system is nice and strong, you have no symptoms, it doesn't affect your organs," Chinsio-Kwong said. "But it can develop into active TB when you're immunosuppressed. So that's where diabetes, smoking or any infectious disease, like HIV, can really put you at higher risk of developing an active TB case."

Routine testing for higher-risk people, such as healthcare workers, can be helpful. Chinsio-Kwong said she was diagnosed with a case of latent TB earlier in her career, prompting her to take a nine-month regimen of treatment.

"If we can appropriately treat all the latent TB cases, we can really reduce the number of active TB cases," she said. "The hope is that you detect latent TB before you develop symptoms — because by the time you have symptoms, you're an active TB case, spreading your germs and possibly even spreading the infection to others."

In Los Angeles County, 91% of tuberculosis cases were among Latino or Asian American residents. The top seven countries of birth of people with TB were Mexico, the Philippines, Guatemala, China, Vietnam, El Salvador and South Korea.

Areas with the highest tuberculosis case rates in regions monitored by the L.A. County Department of Public Health were in central L.A., which the agency defines as including downtown, Echo Park, Silver Lake and the Hollywood Hills; South L.A.; and an area of the western San Gabriel Valley that includes Alhambra, Monterey Park and San Gabriel.

Other areas with TB rates above the L.A. County average include the neighborhoods covering Hollywood, northeast L.A., El Monte, East L.A., Inglewood, Torrance and Bellflower.

Of the regions with L.A. County's highest TB cases, those with the highest mortality rates were in the Alhambra-Monterey Park-San Gabriel area, where 15.4% of tuberculosis cases resulted in death; and Central L.A., where 20.5% of cases resulted in death.

A large problem with TB is that it's possible for doctors to miss a diagnosis, as TB is relatively rare. The California Department of Public Health last month urged healthcare providers to consider tuberculosis as a potential cause of respiratory illness among higher-risk people.

There are situations in which doctors can misdiagnose people with TB. While the disease typically grows in the lungs — leading to symptoms such as chronic cough, chest pain and coughing up blood — the bacteria also can grow in other areas of the body, including the gastrointestinal tract or the nervous system, and doctors might miss a TB diagnosis in that atypical presentation.

Instances of misdiagnosed TB cases previously documented by The Times include a San Fernando Valley businessman, who was raised in Chile and suffered for 11 years until a TB diagnosis was made; and a Shanghai-born UC Berkeley Mandarin lecturer who was misdiagnosed with Crohn's disease and given a steroid to suppress her immune system, allowing her TB to spread. It was only when she lay gravely ill in a hospital that a doctor seriously considered TB.

One prominent misdiagnosis occurred in 2004, when Dr. Claudia Lacson — pregnant with her first child — fell into a coma in Georgia after complaining of severe headaches and a persistent fever. Doctors initially suspected bacterial meningitis, but by the time doctors began TB treatment, it was too late, and she died at age 38, weeks after giving birth to a daughter, who also did not survive.

"What we want providers to know is that when any individual comes to them presenting with respiratory symptoms, they need to start thinking about is: Is this potentially a person who is at risk of having TB?" Chinsio-Kwong said. "Even if you weren't born [in] another country, if you're in close proximity to those who are coming from out of the United States, there's a risk."