She has an extensively drug-resistant form of tuberculosis, or XDR-TB, which is a relatively rare form of the disease that is resistant to at least four of the core anti-TB drugs, according to the World Health Organization 
 
 Contact tracing is underway, and the CDC is seeking people who may have had prolonged close contact with the woman, including those who sat in the same row or near the woman on the flight.  Story highlights Woman traveled from India to the U.S. and later tested for drug-resistant TB 
 
 Contact tracing is underway for people who had prolonged close contact with patient 
 
 (CNN) Health authorities are working to identify people who may have been exposed to a patient with a drug-resistant form of tuberculosis. The patient, who isn’t being identified in any way, may face months or even years of treatment. The symptoms of TB disease of the lungs may also include coughing, chest pain, and coughing up blood. A person needs only to breathe in a small number of these germs to become infected. "TB bacteria are put into the air when a person with TB disease of the lungs or throat coughs, sneezes, shouts, or sings," CDC says. TB is not as easily spread as diseases like the flu or measles. If I have drug-susceptible TB, how can I prevent getting drug-resistant TB? NIAID has treated other XDR-TB patients in the past under this protocol," the NIH said. XDR-TB is rare, however 77 countries worldwide had reported at least one case by the end of 2011. XDR-TB resists the effects of almost all the known TB drugs. The BCG vaccine prevents severe forms of TB in children, such as TB meningitis, but is less effective in preventing pulmonary TB in adults, the commonest and most infectious form of TB. You should tell your health care provider if you are having trouble taking the medications or if you have any side effects. Why does there seem to be more cases of XDR TB now than there were in the past? People who are most at risk, if they do come into contact with someone with XDR-TB, are those with reduced immunity to infectious diseases, such as those with HIV infection or other medical conditions that can weaken a person's immunity. It is also advised that such people should avoid areas where there are no infection control measures in place. Documented places where transmission has occurred include crowded hospitals, prisons, homeless shelters, and other settings where susceptible persons come in contact with persons with TB disease,” CDC advises. If you think you have been exposed to someone with XDR TB disease, you should contact your doctor or local health department about getting a TB skin test or blood test for TB infection. What should I do if I have been around someone who has XDR TB? If TB is found, treatment will be started with the drugs to which the person’s TB is most likely to respond. "The likelihood that this person transmitted the illness is low, but this is a very serious illness so we can't take any chances, and need to get the close contacts in for testing," said Tom Skinner, a spokesperson at the Centers for Disease Control and Prevention.  (PDFCdc-pdf – 421k) 
 
 Extensively Drug-Resistant Tuberculosis (XDR TB) 
 
 What is Extensively Drug-Resistant Tuberculosis (XDR TB)?
– CDC officials say a woman with an extremely rare form of tuberculosis came to the US from India and traveled to three different states before being diagnosed with an active case of the disease. Now she's isolated at a National Institutes for Health clinic in Maryland, and authorities are trying to track down "hundreds of people" who may have come into contact with her, NBC News reports. If it were just a simple case of TB, there wouldn't be such a brouhaha—but the unnamed patient has extensively drug-resistant TB, or XDR TB, which doesn't respond to some of the most powerful anti-TB drugs, per the World Health Organization. Although the disease is rare—the CDC says only 63 cases of it were noted between 1993 and 2011—TB bacteria can enter the air via coughs or sneezes and remain there for several hours, the agency notes. After spending time in India—the country with the largest number of TB cases in 2013, according to WHO—the woman flew back to Chicago in April, then traveled to Missouri and Tennessee over the next seven weeks, notes NBC. CNN points out as many as 8 weeks can pass between exposure and a positive TB test. A spokeswoman for the McHenry County Health Department in Illinois tells the Chicago Tribune it's keeping an eye on some people the woman was in close contact with and that the general public is likely not at risk. An NIH statement says the patient is being treated in a room "specifically designed for handling patients with respiratory infections, including XDR-TB," per NBC; the CDC says she's in stable condition. The CDC reports only 30% to 50% of XDR TB cases can be cured, and treatment can take years, with doctors even performing surgery to remove infected areas.