The cargo jets landed at Travis Air Force Base, about midway between San Francisco and Sacramento, and one continued on to Miramar Marine Corps Air Station near San Diego after refueling.
The United States and other countries are seeking to evacuate their citizens from China, where the coronavirus outbreak has killed at least 490 people, most in and around Wuhan, and infected more than 23,000.
Twelve cases have been confirmed in the United States by the US Centers for Disease Control and Prevention (CDC), the latest reported in Wisconsin on Wednesday.
The Wisconsin patient, who is isolated at home and “doing well,” fell ill after traveling to Beijing and was exposed to known cases while in China, the state health department said.
None of the 178 evacuees placed under quarantine at Travis showed signs of disease, except for a small child who developed a fever during the flight, said Dr. Henry Walke, director of preparedness for the CDC’s National Center for Emerging and Zoonotic Infectious Diseases.
The child and its mother were both taken to a nearby hospital where they will be tested and treated in isolation,Walke said.
The rest of the Travis evacuees will be housed in a hotel on the base. As in other quarantine sites, the CDC will take charge of the care, transportation and security of the evacuees.
“A safety cordon will be established, away from residential housing, to ensure the Travis mission can safely continue,” the statement said.
The same protocols are in place for Miramar as well as March Air Reserve Base near Los Angeles, where the first group of 195 Americans airlifted by the State Department from Wuhan landed last Wednesday and are midway through a two-week quarantine there.
The Pentagon said it is also preparing Camp Ashland, an Army National Guard base in Nebraska, to receive up to 75 people for quarantine.
In New Jersey, state Health Department officials said they quarantined an asymptomatic person who arrived at Newark Liberty International Airport on Tuesday after traveling to Hubei province, where Wuhan is located.
The person will be monitored for symptoms for 14 days.
As part of its health emergency declaration on Jan. 31, the administration announced the extraordinary measure of barring US entry of all foreign nationals who have recently visited China.
The CDC also has ordered a mandatory two-week quarantine for all US travelers who have visited the Hubei province during the previous 14 days.
Americans who traveled anywhere else in mainland China will be subject to 14 days of self-quarantine and health monitoring upon their return.
All commercial flights carrying Americans home from China will be directed to one of 11 US international airports where passengers will be screened for possible exposure to coronavirus and signs of infection.
The State Department also has issued a “Do Not Travel”advisory warning US citizens against visits to China
