The Centers for Disease Control and Prevention issued new Ebola protection guidelines on Oct. 20, more than a week after two nurses in Dallas became infected with the virus while treating Thomas Eric Duncan. The recommendations are based on protocols used by Doctors Without Borders, which tends to Ebola patients in Africa. They also closely reflect procedures that were already in place at many hospitals in the United States, including those in the North Shore-Long Island Jewish Health System and the Nebraska Medical Center in Omaha — one of four facilities in the country equipped to isolate patients with dangerous infectious diseases.