The U.S. Centers for Disease Control and Prevention announced Thursday that a second passenger on the flight has tested positive for TB. The passenger's identity and state of residence are not being released.
Most people who test positive for TB never develop the disease, according to county health department spokeswoman Joy Alexiou.
"There's no way to determine if she's the source or not," unless the passenger develops TB because health officials need to compare strains of the disease from each person to establish a link, Alexiou said.
The Sunnyvale woman was hospitalized at Stanford University within days of her flight. She is now recovering at home, according to Alexiou. Her identity has not been released.
TB is a bacterial lung disease that can remain dormant in infected individuals for years before becoming active and contagious. Symptoms of active TB include fever, coughing, fatigue, weight loss, diminished appetite and coughing up blood. While completely curable, TB can take six to nine months to cure, longer for antibiotic-resistant strains of the bacteria, according to the county health department.
Because of its large immigrant population, Santa Clara County has a larger number of TB cases than the total from 35 U.S. states. The county had 228 cases in 2006.
You can read more about this story in Thursday's edition of the San Jose Mercury News or online here. Then in Sunday's edition of the paper, a closer look at why tuberculosis is disproportionately affecting Silicon Valley.