Natalie Skipper started feeling under the weather a few weeks after returning home from volunteering at a South Africa hospital. "The worst flu I had ever had in my life," she said.
Her temperature hit 105 degrees. She had trouble walking.
She didn't have the flu.
Ms. Skipper, a 34-year-old physical therapist with a love of travel, was infected with tuberculosis. And not just any tuberculosis. She brought to Tennessee a strain that can't be cured with the most potent and common drugs used against the deadly disease. Multidrug-resistant TB is at epidemic proportions in some parts of the world—a growing problem the U.S. is surprisingly unprepared for.