Photo: Courtesy of Shanghai Airport

The case of Omicron variant detected in Guangzhou, Guangdong Province, was an imported case flying back from Canada on November 27, authorities in Shanghai revealed on Wednesday.

The person received quarantine upon arrival in Shanghai. During the quarantine period, his four tests results were all negative and he showed no symptoms of fever, according to the local government of Shanghai on Wednesday in a release on specific travel routes of the case within Shanghai. 

The case, a 67-year-old man, then returned to Guangzhou by flight CA1837 from Shanghai on December 11 and was detected to be infected with Omicron in Guangzhou while undergoing home quarantine in Guangzhou on Monday, Guangzhou Municipal Health Commission reported.

As a critical transit point of the Omicron-infected case, Shanghai took precautionary measures. A total of 799 people were screened and their tests results turned to be negative. Environmental testing samples were also negative.

On Wednesday, Central China's Henan Province reported one close contact of the Omicron-infected patient in Guangzhou. They were on the same flight when returning from Canada to Shanghai on November 27. 

It is unknown how many people were in the same flight with the Omicron-infected patient in Guangzhou, and the status of the rest of the passengers is also not known.

The Chinese mainland reported the first case of Omicron variant on Monday night. Local health authority in North China's Tianjin where the mutated variant was detected said on Tuesday that the Omicron case was imported from Europe. The person had normal temperature when they entered China through Tianjin.

So far, no other Omicron infections have been detected among other passengers who were on the same flight, according to the authorities.

While the Chinese mainland detected two cases with the Omicron strain, domestically-transmitted epidemic has yet to show any easing signs. On Tuesday, the mainland registered 50 confirmed cases, including 45 from East China's Zhejiang Province and two from Guangdong's Dongguan and three from Inner Mongolia.

Affected by the epidemic, the Shanghai Library closed on Wednesday. It is unknown how the library was affected.

Dongguan, where two confirmed and two asymptomatic cases have been reported since December 13, started to give nucleic acid tests to all residents in the city. 

Shenzhen, a city that borders Dongguan, requires commuters from Dongguan to receive a nucleic acid test every two days in a move to heighten alert against potential epidemic flare-up.

Global Times