Last May, a elderly man was admitted to the Brooklyn Mount Sinai Hospital for abdominal surgery. A blood test revealed he was infected with a newly discovered germ. Doctors isolated him in ICU. Over the last five years, it has hit a neonatal unit in Venezuela, swept through a hospital in Spain, forced a British medical center to shut down its ICU, and taken root in India, Pakistan and South Africa. Recently C. auris reached New York, NJ and Illinois, leading the federal CDC and Prevention to add it to a list of germs deemed “urgent threats.” The man at...