BEIJING — China is capable of preventing an imported virus outbreak with "three defense lines" as growing imported novel coronavirus disease (COVID-19) cases have been reported on the Chinese mainland, a medical expert said on March 24.

Customs administration has been the forefront of identifying imported patients through temperature testing and checking passengers' travel records during the past 40 days, said Wu Zunyou, an epidemiology expert at the Chinese Center for Disease Control and Prevention, at a press conference.

Inbound personnel are quarantined for 14 days to cover the incubation period of the virus, the interval between infection and the onset of symptoms, which is the second defense line, he said.

People exhibiting COVID-19 symptoms would be sent to designated hospitals for treatment, Wu said.

Experienced medical staff are the reserve to deal with possible confirmed COVID-19 patients who are not found by the first two rounds of checks, Wu said, adding that no imported case has been identified by the final defense line so far.

China reported 74 imported COVID-19 patients on March 23 and 427 imported cases had been reported by the end of March 23.