Customs workers check an inbound passenger's health information card in Shenzhen, South China's Guangdong province, on April 3, 2020. [Photo/Xinhua]

Guangdong province, with its outward-oriented economy, has been implementing what it calls a "five-shield" system in its efforts to prevent the spread of coronavirus inspections from people traveling to China. 
The system consists of quarantines at checkpoints, medical observation and isolation at designated venues, community screening, fever clinics and treatment at hospitals, He Jianfeng, chief expert of the Guangdong Center for Disease Control and Prevention, said on Tuesday.
Since March 21, all travelers from abroad have been required to undergo medical observation at designated places. 
To intercept any potential risks brought by travelers from overseas who entered Guangdong before that date, community screenings have been carried out. About 47,800 people have been tested. 
The screenings identified five cases of coronavirus infection in Guangzhou, all from Nigeria, Africa. Four of the infected people had traveled from overseas. Five cases were found to be related to the four travelers.
As of Monday, the province had reported 173 imported coronavirus cases, 136 of which were Chinese nationals, He said.
As the epidemic is expanding rapidly around the globe, Guangdong faces pressure to avoid importing new infections, given its robust economy and frequent overseas exchanges. 
Additional risk also lies in the resumption of economic activity in the province, so high vigilance continues to be necessary, He said, adding that the province has acquired useful experience, capacity and confidence in fighting the epidemic.