This XDR strain is the one carried by the man now being held in isolation.
Few, if any, of the current therapies work against this strain, making it a growing problem worldwide.
In fact, the number of countries in which XDR-TB has surfaced has recently nearly doubled from 19 to 35 in a single year. Some of these outbreaks have occurred in European nations.
Worse, while the test for TB infection takes several days at most, the test to determine infection with XDR-TB can take between six weeks and 16 weeks, according to the CDC.
The most common symptoms of tuberculosis are fever, chills, night sweats, weight loss, fatigue, loss of appetite and coughing up blood.
Since most of those exposed to the disease will first pass through a latent phase, they will usually be symptom-free shortly afterward, and they will not be contagious during this time.
If you think you may have been exposed to tuberculosis, you can visit your doctor for a skin test that will reveal in 48 hours to 72 hours whether you have been infected.
If the test is positive and you do not have symptoms, your doctor will prescribe a course of medications that you will take over the next nine months or so. These medications decrease the chance that you will get active tuberculosis in the future.
If your doctor believes that you have active tuberculosis, you will most likely be hospitalized and placed in an isolated room while doctors conduct further tests.
The isolation period for preliminary tests is at least three days, but it can stretch to two weeks or more if your test results are positive.
In most cases, the answer to this question is yes. Treatment for active tuberculosis consists of four drugs to be taken anywhere from four months to a year, or even longer.
However, resistant strains of tuberculosis such as XDR-TB cannot be treated with regular medications. Even when these patients are treated with the best medications available, half of people with MDR-TB, and almost all with XDR-TB will die.
So far, these resistant infections have been very rare in the United States. The best way to avoid resistant TB is to make sure that everyone with TB gets the full course of appropriate treatment.
If you or someone you know has been exposed to tuberculosis, or has any of the symptoms discussed above, you should contact your doctor or the local health department to get tested.
Reports from Dr. Sami Beg and Beata Casanas contributed to this piece.