Obama says world needs to learn from Ebola 'wake-up call'

By Roberta Rampton WASHINGTON (Reuters) - President Barack Obama said on Wednesday that he was bringing back nearly all U.S. troops fighting the Ebola epidemic in West Africa and marking a new phase in the battle to help countries "get to zero" cases of the deadly disease. Obama said the outbreak was a "wake-up call" for the world, and that wealthy countries needed to invest to ensure that poor nations have basic health systems to detect and fight diseases. "This is not charity," he said in a sp