Medical workers from Nanfang Hospital collect samples for nucleic acid tests in Liwan District of Guangzhou, south China's Guangdong Province, May 27, 2021. Liwan District of Guangzhou has carried out COVID-19 nucleic acid tests for all citizens from May 26 to 27. Photo:Xinhua

Positive COVID-19 cases reported in South China's Guangzhou have been traced to one transmission chain, but patient zero has yet to be found 20 days after the first case was reported, a health official said on Tuesday.

Since May 21, Guangzhou, capital city of South China's Guangdong Province, has recorded a total of 98 confirmed cases, most of whom are patients with mild symptoms, as well as 10 asymptomatic cases. 

Li Tiegang, an official with the Guangzhou health commission, told China Central Television that the genetic sequencing of positive cases discovered in Guangzhou show at least 98 percent similarity, indicating that all positive cases are in the same transmission chain. 

New cases are likely to emerge in the future but will be in restricted zones. The risk of spreading the virus to other zones is low, Li said, adding that more investigation is needed to identify patient zero.

A total of 10 positive cases out of a population of 19 million were found in the mass nucleic acid testing, which started June 4. The positive rate is low and within the expected range, showing low community transmission rate, Li said. 

Guangzhou on Tuesday ordered cinemas, theaters, KTVs, internet cafes and other entertainment venues to suspend business amid rising infections. 

Several districts in Guangzhou have imposed stricter epidemic prevention measures after newly reported cases in the city recorded a new high over the past five days.

Global Times