In some people who breathe in the mycobacterium, it is "inactive but alive" in the body, Anderson said. That person has no symptoms, doesn't feel sick and can't spread it. At some later point, though, it can become active, so Kriesel said those with a positive skin test for TB are treated.

Treatment for TB that's not drug-resistant consists of pills containing antituberculosis agents, similar to antibiotics, but effective specifically against the mycobacterium. A patient is given the four recommended drugs seven days a week or five days a week for eight weeks, then two of them are dropped and the other two continue for another six months.

Tuberculosis is relatively uncommon in young people compared to older people, who are also more likely to have reactivation disease, although the risk is still low.

Salt Lake Valley Health Department infectious disease expert Kyle Cannon said they see "bumps" in the numbers in the very young, the very old, and late teens and early 20s.

While risk of spread is relatively low, health officials take it very seriously. They actually watch someone with TB take the needed medication, Cannon said. And people who refuse treatment can be forcibly quarantined and treated under court order.

Taylor said health-care providers have to notify the state when they find TB in a patient, then coordinate treatment.

Andrew Speaker, the Atlanta man quarantined with a dangerous strain of tuberculosis, will likely spend up to two months in a hospital while he receives a battery of antibiotics and is evaluated for possible surgery, his doctors said.

Speaker is the first infected person quarantined by the U.S. government since 1963. In a TV interview Friday, Speaker apologized to airline passengers and crew members he may have exposed to the infection while on a trans-Atlantic flight.

Twenty-six students and two faculty members from University of South Carolina Aiken were aboard the May 12 flight from Atlanta to Paris. Many on the flight are now anxiously awaiting the results of their TB tests, though two people have tested negative, South Carolina health officials said.

Health officials have contacted 74 of the 310 U.S. citizens who were on the flight, according to the Centers for Disease Control and Prevention. That count includes all 26 who sat in the five-row area around Speaker — the ones considered at greatest risk.

None is exhibiting symptoms, CDC officials said.

Speaker, 31, said he, his doctors and the CDC all knew he had TB that was resistant to some drugs before he flew to Europe for his wedding and honeymoon last month. But he said he was advised at the time by Fulton County, Ga., health authorities that he was not contagious or a danger to anyone.