Oh crap: The United States now has its first-ever case of a contagious, aggressive, and drug-resistant form of tuberculosis, according to the Associated Press. The patient is Oswaldo Juarez, a 19-year-old Peruvian who came to the U.S. to study English. Only a handful of people in the world are thought to have been infected by the rare strain of the disease—but it killed 52 of the first 53 people it infected in South Africa three years ago. Tuberculosis is the top infectious killer of adults in the world, and it lies dormant in one out of three people, 10 percent of whom will develop active infections. Drug-resistant TB develops when the normally cheap TB medication is stopped short.