Wuhan, the original epicentre of the new coronavirus outbreak in China, has tested over 3 million residents for the pathogen since April, and will now focus its testing efforts on the rest of its 11 million population, according to state media.
Once the tests of everyone living in the city are completed it should give authorities a clear indication of the number of asymptomatic cases as businesses and schools reopen, the official Xinhua News Agency reported late Thursday.
The priority will be given to residents who have not been tested before, people living in residential compounds that had previous cases of infection, as well as old or densely populated estates, Xinhua said, citing a Wuhan government meeting.
Fears of a second wave of infections flared over the weekend, after Wuhan reported a cluster of infections, the first since a virtual lockdown on the city was lifted on April 8, raising fears of a second wave. The latest infections were previously asymptomatic cases, people who had the virus but showed no symptoms such as a fever.
Reuters, citing an internal document to district officials, reported on May 11 that the city planned to conduct the campaign of city-wide nucleic acid tests over 10 days. That would entail millions of tests being conducted in a narrow time frame.
Wuhan conducted a total of 1.79 million tests from April 1 to May 13, according to Reuters calculations based on daily reports published by the city's health commission.
If Xinhua's report that 3 million tests have been conducted since April also uses figures from the health commission, it would suggest that up to 1.2 million tests were administered on May 14 alone.
The health commission will publish the May 14 figures later on Friday.
Recently, Wuhan has detected between several and more than a dozen asymptomatic infections every day.
Some experts say the mass testing is unprecedented in scale, and shows the level of concern. Others warn on potential testing errors due to the sheer size of the sampling.
PREVENTING A REBOUND
On Friday, China reported four new confirmed cases in the mainland for May 14, up from three cases a day earlier, the National Health Commission (NHC) said in a statement on Friday. All of the new cases were locally transmitted.
Recent outbreaks in northeastern Heilongjiang province and Jilin city have contributed to fears of secondary outbreaks.
"The epidemic situation is now fragmented domestically, but the task of preventing a rebound of the epidemic remains arduous," said Zeng Yixin, a vice minister at the NHC, told a news conference on Friday.
"The epidemic situation abroad is still severe and complex, and the pressure to defend against the outside continues to increase," Zeng added, referring to what China calls imported cases of citizens returning from abroad infected with the virus.
China has stopped foreigners entering the country as a precaution against imported infections.
Zeng also said that some COVID-19 vaccines are set to complete their second-phase clinical trials in July.
The total number of confirmed cases in mainland China now stands at 82,933 while the death toll remained unchanged at 4,633.
China does not include asymptomatic virus carriers in its tally of confirmed cases. It also does not disclose the overall number of asymptomatic cases in the country.