Enlarge /. WUHAN, May 15, 2020 – Residents do nucleic acid testing on a test post set up at a primary school in Dongxihu District, Wuhan, central China's Hubei Province, on May 15, 2020. Wuhan will organize nucleic acid testing for all residents who have not done so, to have a better understanding of the number of asymptomatic cases of the new coronavirus.
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When Chinese officials discovered a group of only six COVID-19 cases in Wuhan City about two weeks ago – the first cases in more than a month – they quickly set an ambitious plan to cover the entire city of around 11 million people to test and destroy a possible second wave of infection. And they originally planned to try in just 10 days.
Ten days later they almost achieved this goal. According to state media, the Wuhan Municipal Health Commission dabbed more than 9 million residents between May 15 and 24, and tested more than 6.5 million of these smears for coronavirus genetic material.
According to the New York Times, laboratories in the city went from 46,000 tests a day to up to 1.47 million in the screening sprint. The Times notes that New York has tested 1.7 million people in the U.S. since March 4, an almost three-month period, according to The Atlantic's COVID Tracking Project.
Wuhan officials completed the mass demonstration in a staged neighborhood-by-neighborhood round. Then they accelerated swab processing by performing batch tests. That is, they combined material from five to ten swabs and tested the pooled sample all at once. If one of the pooled swabs was positive for the novel SARS-CoV-2 coronavirus, officers could return to that handful of people and test them again. This type of batch test is well suited to quickly run through a population in rare cases.
So far, 218 asymptomatic cases have been identified in the test campaign, Wuhan officials reported. These cases are now in quarantine.
Now that most of the testing has been completed, city officials are working to "check the leaks and fill the gaps" to ensure that no residents are missed.
Some residents have told The Times that they are against the test campaign because it requires more contact with others, which may put them at risk of infection. However, others argued that the tests offer psychological benefits when people go back to work.
"This attempt to test everyone would improve the city's vitality and provide a scientific basis for resuming work," said Yang Zhanqiu, a virologist at Wuhan University, The Times. "It can also make people feel good and everyone can be reassured."