The contaminant has been linked to the deaths of more than 300 children in Africa and Asia
Only with strict adherence to health measures, from wearing masks to avoiding crowds, would the world be able to beat it, Tedros added at a virtual news briefing in Geneva.
"Where these measures are followed, cases go down. Where they are not, cases go up," he said, praising Canada, China, Germany and South Korea for controlling outbreaks.