The yeast is called Candida auris and was first identified in 2009 in a Japanese patient with an ear infection. Since then, it’s been found in a handful of countries around the world. In June, the U.S. Centers for Disease Control and Prevention asked doctors to look for it. They found 13 cases over the summer, the CDC reports. Some strains of the fungus resist all the classes of antifungal drugs used to fight it. The CDC described seven cases in detail that could be treated with antifungals, although they all resisted at least one class of the drugs. “Five of seven isolates were resistant to fluconazole; one of these isolates was resistant to amphotericin B, and another isolate was resistant to echinocandins. No isolate was resistant to all three classes of antifungal medications,” the CDC team wrote in the report released Friday.