Ebola is a deadly contagious disease. From 1975 to 2013, the virus killed about 1500 people. But a 2014 epidemic killed nearly seven times that number. At first the outbreak was contained to one country. But soon it spread to two other. The virus was on the move, and people were scared. When two American health-care workers became infected and were sent to the United States for treatment, many people feared a pandemic - an outbreak that would spread all over the world. Could it happen?.
