China detects second case of Omicron variant

China detected on Tuesday the second case of Omicron variant in a traveler, more than two weeks after he arrived in the country from overseas. Chinese authorities did not reveal when, where or how the man caught the virus.

The case, reported in the southern city of Guangzhou, came a day after health authorities in the northern port city of Tianjin said they detected mainland China’s first Omicron infection, also in a traveler who arrived from overseas.

The Tianjin case was identified as an asymptomatic carrier on arrival. He was already in quarantine when genome sequencing confirmed he had the Omicron variant, suggesting that he has no direct interaction with other citizens.

The second case, a 67-year-old man, entered China on November 27 in Shanghai and underwent two weeks of centralized quarantine, during which he repeatedly tested negative.

The man then flew from Shanghai to Guangzhou in a nearly full flight, according to CNN. He entered into home quarantine, where he tested positive in the early hours of December 13.

Subsequent genome sequencing reviewed by the Chinese Center for Disease Control and Prevention confirmed it was the Omicron variant, according to authorities.

He is now being treated in isolation in hospital, officials said.

Following his diagnosis, 10,544 people connected to the man have been tested for the virus, so far all results have returned negative. Much remains unknown about the highly contagious Omicron variant, including its incubation period.

Chinese public health experts and state media have voiced confidence in the country’s zero-tolerance strategy, composed of mass testing, snap lockdowns, and extensive quarantines.

In China, all overseas arrivals must be tested for Covid-19 before they leave the airport, followed by at least two weeks of centralized quarantine. This spends after another lengthy period of home isolation. And throughout the process, international arrivals are prevented from coming into contact with the wider community until they have completed the required quarantine process.