New coronavirus clusters have surfaced around the world as nations struggle to balance reopening economies and preventing a second wave of infections, while a top global health official warned Wednesday that COVID-19 could be around for a long time.

Authorities in the Chinese city of Wuhan, where the pandemic first began late last year, reportedly were pressing ahead Wednesday to test all 11 million residents for the virus within 10 days after a handful of new infections were found.

In Lebanon, authorities reinstated a nationwide lockdown for four days beginning Wednesday night after a spike in reported infections and complaints from officials that social distancing rules were being ignored.

A top World Health Organization official, meanwhile, warned that it's possible the new coronavirus may be here to stay.

"This virus may never go away," Dr. Michael Ryan said in a press briefing Wednesday. Without a vaccine, he said it could take years for the global population to build up sufficient levels of immunity.

"I think it's important to put this on the table," he said. "This virus may become just another endemic virus in our communities," he said, noting that other previously novel diseases like HIV have never disappeared, but that effective treatments have been developed.