A group of 195 U.S. citizens and diplomats and their families who were evacuated from Wuhan, China by the State Department this week are now under a federally ordered two-week quarantine at a military base in Riverside, California. It's the only instance of such a mass quarantine to be ordered by the Centers for Disease Control (CDC) since the coronavirus outbreak began.

Matthew McCoy, a theme-park designer who is among the evacuees, says that the flight on Wednesday was truly "surreal," with the flight crew and medical personnel all in hazmat suits. As he tells the New York Times, "They were trying to keep us calm, but they had these guys covered from head to toe taking your temperature. It felt like a C.I.A. cargo plane."

The 195 individuals on the plane, none of whom have shown any symptoms of the virus, were under voluntarily quarantine starting Wednesday at March Air Reserve Base, but as of Friday that quarantine became official. As the Times reports, 14 days is believed to be the incubation period for the virus, and the group of evacuees is now being held under federal orders from the CDC — which has the rarely used power to order quarantines. The U.S. government hasn't ordered such a quarantine since the 1918 Spanish flu pandemic.

Only one person-to-person transmission of the coronavirus has occurred in the U.S., and it was between a husband and wife in Chicago after the wife had returned from a trip to Wuhan. They are among just five known cases in the U.S., with others that have appeared in Washington State, California and Arizona.

Scarily, not everyone shows severe symptoms from the virus, and it appears to be much more easily transmitted between people than the SARS virus was. The New England Journal of Medicine reports this week that person-to-person transmission occurred from an asymptomatic patient in Germany — he is believed to have given the coronavirus to a colleague from Shanghai, who then began showing symptoms on her flight back to China. The German patient, however, only had mild symptoms for about 24 hours and then returned to work, and he then later tested positive for the virus after the Shanghai woman's contacts were reviewed.

Per the Times, the scene at the March Air Reserve Base in Riverside is pretty bizarre, with people hanging out watching movies, playing catch with their kids, and taking "jogs down tree-lined paths" while also getting their temperature taken multiple times a day, and getting their nasal passages swabbed.

One individual apparently refused to submit to the voluntary detention after landing on Wednesday, but that person was then quarantined by Riverside County.

As of Friday, three major U.S. airlines — United, Delta, and American — announced wholesale suspensions of all their routes in and out of China for several months. Earlier this week, United became the first carrier to suspend some flights to China, claiming it was due to "load factors" and the lack of demand for travel to the country.