The malaria parasite — carried by infected mosquitoes from person to person — still kills an estimated 655,000 people a year.

That’s almost 2,000 a day, mostly in Africa, with children being most at risk.

If the world loses its front-line drug, the impact could be devastating.

“The nightmare scenario is that the resistance will travel,” Nosten said.

“We know what will happen in Africa when resistance is bad because we’ve been there before in the 1990s with chloroquine (another anti-malarial drug) … millions of deaths,” he warned.