When the Ebola virus hit home in the United States in September, Sandra Ward, an emergency room nurse at Kaiser Permanente Medical Center in Walnut Creek, was eager to get the latest training to protect herself. But during a session in which nurses practiced putting on protective gear, she noticed the hood was missing, leaving her exposed. "We see this picture of a hood that the CDC (Centers for Disease Control) has started recommending a couple of weeks ago, but we haven't gotten it yet," Ward said last week. "It scares me." That fear has sparked a vigorous debate over how much preparation and training is enough for health care workers to deal with the Ebola virus, after two Texas nurses contracted the disease from an infected patient.