LOS ANGELES — About 200 Americans evacuated from Wuhan, China, landed at a military base in Southern California on Wednesday, as countries around the world began pulling their citizens from the epicenter of the coronavirus outbreak.

“The whole plane erupted in cheers when the crew said, ‘Welcome home to the United States,’” said Dr. Anne Zink, the chief medical officer for Alaska, where the plane stopped en route to California.

But “home” was not immediately in the cards for the evacuees.

Upon landing at the March Air Reserve Base in Riverside, the passengers were met on the tarmac by personnel in biohazard suits, loaded onto waiting buses and instructed to remain on the base for three days of medical screening. Only when they are cleared will they be allowed to continue on home.

The authorities, however, were at pains to to say it was not a quarantine.

“We are respecting the rights of them as individuals,” said Dr. Nancy Knight, a senior official with the federal Centers for Disease Control and Prevention. “We are doing that in a way that protects their health, the health of uniformed service members and the health of the community.”