The city has ramped up its testing capacity over the past two weeks, in sharp contrast with the early weeks of the outbreak when the government struggled to find enough testing kits. Lab technicians were able to speed up the process by pooling samples together to be tested in batches.

Laboratories went from processing around 46,000 tests a day, on average, before the drive, to as many as 1.47 million tests on Friday. By comparison, the state of New York has tested 1.7 million people since March 4, according to The Atlantic’s COVID Tracking Project…

But with confirmed, symptomatic infections remaining in the single digits in Wuhan, some experts said the scale of Wuhan’s campaign was excessive. Jin Dongyan, a virologist at the University of Hong Kong, said it would be impossible to accurately test that many people in such a short period.

Under ordinary circumstances, nucleic acid tests for the coronavirus are difficult to administer in hospitals, even with well-trained nurses, Dr. Jin said. Trying to conduct so many of them, in quick succession, in makeshift testing tents, could produce many erroneous results.