Chinese customs has now become the new frontline of battling the COVID-19 pandemic as China has recorded over 800 imported cases, surpassing the number of new local cases.

Wearing face masks, goggles and protective suits, frontline customs officers are now working day and night at airports to inspect and manage the entry of all foreign arrivals. 

Xie Lihui is one of them. She detected the country's first infected case at the customs in Beijing Capital International Airport on January 23.

China's General Administration of Customs required all passengers inbound and outbound through airways or waterways to report their health conditions starting January 26. But before that, there were only temperature checks at the customs, and it largely relied on the inquiries of customs officers to detect the suspected infections.

Xie stopped a passenger who planned to travel with his wife and child abroad at the customs since she noticed he had a relatively higher temperature and a red face.

After inquiring about his information, she realized something wasn't right with this passenger as he had symptoms such as fever and cough, and also came from a severely affected region.

She later sent the passenger to a designated hospital for health check, and only after three days, he was diagnosed with novel coronavirus.

Her responsible and rigorous attitude towards the control and prevention work had helped reduce one exported case at the customs.

With the outbreak gradually under control in China while spreading fast in many overseas countries, the main focus of the control and prevention work at the customs has now shifted from preventing exported cases to preventing imported cases.

Beijing Capital International Airport is the one of the busiest airports in the world, with about 60,000 foreign arrivals on a single day during peak hours. 

Amid the severe situation around the world, the increasing number of foreign arrivals has posed as a great challenge for customs officers.

Since China tightened the regulation on health checks for foreign arrivals, customs officers had to work for prolonged hours to make sure the airports run smoothly.

Measures such as requiring all passengers entering the country from overseas to undergo nucleic acid test and concentrated quarantine for 14 days were imposed to curb the imported cases.

China also decided to temporarily suspend entry into China by foreign nationals holding visas or residence permits still valid to the time of this announcement, effective from midnight, March 28, 2020, according to Chinese Foreign Ministry. 

To reduce the pressure of airports, China's civil aviation regulator ordered further cuts to flights in and out of the country as part of the efforts to contain the increasing risks of imported cases.

All domestic airlines will be allowed to operate only one flight to each country per week, while foreign airlines are instructed to reduce their international routes to China to one per week and only operate one route into the country starting from March 29, according to the Civil Aviation Administration of China (CAAC).

From March 29 to April 4, the number of planned flights is only 108, which is equivalent to 1.2 percent of the total international flights before the outbreak, Jin Junhao, an official from CAAC, told Xinhua News Agency. 

He added that the number of foreign arrivals from March 29 to April 4 is expected to drop from 25,000 to 4,000. 

He said that the new measures have taken effect due to newly imposed measures, including diverting all international flights bound for Beijing to 12 designated airports on their arrival in China, since the previous quarantined passengers had nearly filled up hotels in Beijing.