A staff member (left) briefs clients on face mask raw material and techniques in the Guangzhou international medical protective supplies fair at Poly World Trade Center Expo in Guangzhou, South China's Guangdong Province, June 10, 2020. Photo: Xinhua

The domestic asymptomatic case of COVID-19 in South China's Guangzhou reported on Thursday has been tracked to a strain of the coronavirus bought to the city by an inbound traveler, local Center for Disease Control and Prevention (CDC) confirmed on Sunday. Guangzhou has conducted 148,295 tests for the virus, and none was positive.

The man, surnamed Wang, 40, was infected by improper contact with quarantined travelers from overseas at a hotel where he worked, local CDC authorities said on Saturday, saying the risks are controllable. 

Wang did not carry out proper protection with no gloves or shoe covers and a poor fitting protection suit while he assisted the quarantined guest at the hotel who was infected.

The CDC completed gene sequencing analysis of the virus that infected Wang on Sunday, and found it match an imported case in isolation at the hotel where Wang worked.

Test results of places Wang traveled to are also negative. Wang's close contacts are in quarantine and remain in good health, said the CDC.

The local CDC in Qingdao, East China's Shandong Province, which earlier reported 13 confirmed coronavirus cases, said there is no risk of community infection in the city, after no positive cases were found among 10,920,411 coronavirus tests as of Saturday.

China's top respiratory disease specialist and epidemiologist Zhong Nanshan applauded China's effective control on the epidemic during the 8-day National Day holidays. 

"Over the past National Day holidays, China received 637 million domestic and foreign tourists, which fully proves that our epidemic situation is well under control," Zhong told the World Young Scientist Summit on Sunday in East China's Zhejiang Province.