The Chinese city of Wuhan, where the coronavirus was first detected late last year, has evaluated nearly 10 million people in an unprecedented 19-day campaign to verify an entire city.
He identified only 300 positive cases, all of which had no symptoms. The city found no infections among 1,174 close contacts of the people who tested positive, suggesting they were not easily transmitting the virus to others.
That’s a potentially encouraging development due to widespread concern that infected people without symptoms could be the silent spread of the disease.
“It not only makes the people of Wuhan feel at ease, but it also increases people’s confidence throughout China,” Feng Zijian, deputy director of the China Center for Disease Control and Prevention, told the state broadcaster. CCTV.
There is still no definitive answer on the level of risk posed by asymptomatic cases, with anecdotal evidence and studies to date that produces conflicting responses.
Wuhan was by far the most affected city in China, accounting for more than 80 percent of the country’s deaths, according to government figures.
Almost all over 5 years evaluated
A city official announced Tuesday that the city completed 9.9 million tests from May 14 to June 1. If those previously tested are included, virtually everyone 5 years and older in the city of 11 million people has been evaluated, said Li Lanjuan, a member of a team of experts from the National Health Commission.
“Wuhan City is safe,” he said at a press conference with city officials.
The campaign was launched after a small group of cases were found in a residential complex, raising concerns about a possible second wave of infections when Wuhan emerged from a two-and-a-half-month blockade.
The industrial city on the Yangtze River in central China spent 900 million yuan (about C $ 169 million) on the tests, the official Xinhua news agency said. He quoted Deputy Executive Mayor Hu Yabo saying the cost was “totally valuable” to reassure residents, lifting a “psychological lockdown.”
Tests sometimes give false positives
Clarence Tam, an assistant professor of public health at the National University of Singapore, called the results reassuring but said more information is needed on the value of this type of mass detection when the risk is already low.
He noted that the tests, while generally accurate, sometimes give a positive result for uninfected people, and the very low number in Wuhan was within the expected error range.
“As more countries adopt mass detection strategies, one challenge will be trying to minimize the chances of detecting false positives,” Tam said in an email response to The Associated Press. “This has some implications, because in Wuhan, for example, those who tested positive and more than 1,000 of their contacts were quarantined.”
Rapid testing of so many people as possible in part through batch tests, in which samples of up to five people are mixed, Xinhua reported. If the result is positive, then people are evaluated individually.
National resources were also mobilized to help, said Wang Weihua, deputy director of the Wuhan Health Commission, according to Xinhua. Together, these efforts raised Wuhan’s daily testing capacity from 300,000 to more than one million, according to the quote.