People who had close contact with a new asymptomatic novel coronavirus carrier, as well as those in places near the carrier's home and workplace, have all tested negative after the case was identified in Guangzhou, Guangdong province, on Saturday.
The asymptomatic carrier, surnamed Xu, delivered meals and cleaned rooms at the Tokai Hotel, a quarantine site in Yuexiu district.
It's thought that she was infected while collecting trash at the door of a room on Wednesday afternoon, Zhang Zhoubin, deputy director of the Guangzhou disease control and prevention center, told a news conference in Guangzhou on Sunday.
The room was occupied by an identified case who had arrived from abroad and was confirmed to be a COVID-19 carrier on Saturday. The nucleic acid sequence of the novel coronavirus found in Xu was identical to that of the Delta variant found in the person in quarantine, surnamed Yang.
Xu, 42, had been living at the hotel since Aug 30, and the risk of transmission in the community was low, said Chen Bin, deputy director of Guangzhou's health commission. Xu is under medical observation at Guangzhou Eighth People's Hospital.
Fifty-six people are working at the Tokai, where 103 people are being quarantined. Since August, seven imported novel coronavirus cases have been reported at the hotel.
Widespread nucleic acid testing was carried out in several subdistricts of Yuexiu. By midnight on Saturday, all 92,185 samples collected in the district had tested negative.
By 10 am on Sunday, a total of 97,878 samples had been collected in the district, said Guo Huan, deputy chief of the district, adding that the Tokai and some adjacent buildings had been put under control.
Because Xu stayed at home in Haizhu district and moved around the area on Aug 28 and 29, the building where her home is located and some adjacent buildings were locked down, said Fu Xiaochu, deputy chief of Haizhu. A total of 35,293 samples from people in Haizhu district have all tested negative.
Environmental samples collected in Yuexiu and Haizhu also all tested negative. All people who have had close contact with Xu have been put under medical observation at designated places.
The mutations of the novel coronavirus have posed a huge challenge to epidemic control efforts, and the risk of imported infections has risen in Guangzhou, Chen said.
On Saturday, Lin Keqing, executive vice-governor of Guangdong, Zhang Shuofu, Party secretary of Guangzhou, and Wen Guohui, mayor of Guangzhou, directed epidemic control work in Yuexiu.
At a meeting to discuss epidemic control on Saturday, city authorities requested that a check of all quarantine hotels across the city be carried out. Workers at the hotels should be precisely classified according to different levels of risk and put under strict closed-loop management accordingly.