New York Mayor Bill de Blasio (C) and New York Governor Andrew Cuomo (R) attend a news conference in Bellevue Hospital in New York October 23, 2014. A physician with Doctors Without Borders (MSF) who returned to New York City after treating Ebola victims in West Africa tested positive for the virus, setting off fresh fears about the spread of the disease. Dr. Craig Spencer, 33, is in isolation at Bellevue Hospital. Two friends and his fianc?e have been quarantined. At a news conference, de Blasio sought to reassure the public that they are safe from Ebola. REUTERS/Eduardo Munoz (UNITED STATES - Tags: HEALTH POLITICS)