Even before West Africa's Ebola epidemic is under control, public health officials are looking ahead to where the next health disaster will come from.

Tom Frieden, director of the Centers for Disease Control and Prevention, says it's urgent to shore up the world's blind spots, so officials can find and respond to a brewing infection before it becomes a crisis.

The Obama administration requested $600 million earlier this month to implement what it calls the Global Health Security Agenda, working with an international coalition to help high-risk countries improve disease detection and guard against the next contagion.

Outbreaks often prompt calls for improvement that fade when the disease does. Members of Congress are asking if, when Ebola ends, the U.S. will leave West Africa better prepared for a future outbreak.