The time it takes to trace information on international flights with around 300 passengers has been reduced from two hours to 20 minutes in Shanghai, according to Shanghai Customs.

Workers in protective suits are seen at a makeshift nucleic acid testing site inside a parking lot of Shanghai Pudong International Airport on Nov 22, 2020. [Photo/Agencies]

All entry personnel on flights to Shanghai are required to digitally declare their health conditions for the prevention and control of COVID-19.

The customs said the accuracy of key data has reached 100 percent to meet the demand for automatic statistics collection and fast tracing.

At the Shanghai Pudong International Airport, the customs use mobile labs for nucleic acid testing in an effort to screen inbound passengers on the spot.

The data can be shared with local border inspection and health authorities, facilitating coordination between different departments, the customs said.