In the who presentation, Dr Bruce Aylward mentioned this. I'll try to dig up the exact spot in the clip for you. At 1:07:44 this is discussed in depth: https://youtu.be/-o0q1XMRKYM
Thanks for the link! He says that there have been door to door testing of temperatures, and I'd nitpick by saying that's not quite the same thing as testing everyone for the virus, but it is better coverage than I had realised.
Surprised! I worry about unintended consequences. During an epidemic, officials visit every home! Potentially spreading the virus unintentionally thru healthcare personnel. Don't know if I'd open the door to somebody who admits having visited thousands of people before getting to me...
After he said that someone else from the WHO contradicted him.
"The claim was quickly challenged by an infectious diseases expert who serves on a committee that advises the WHO’s health emergencies program.
Gary Kobinger, director of the Infectious Disease Research Center at Laval University in Quebec, said it would be highly unusual for there not to be mild or symptom-free cases that are being missed. He pointed to the fact that outbreaks have popped up in countries far from China — including Iran and Italy — because people with mild infections were not detected and traveled to other places.
'There are mild cases that are undetected. This is why it’s spreading. Otherwise it would not be spreading because we would know where those cases are and they would be contained and that would be the end of it,' said Kobinger, who insisted that mild, undetected infections cannot be ruled out until people who haven’t been diagnosed with the illness can be tested for antibodies to the virus.
'As long as we do not have good serology data, I think that it is completely speculative to say that there are no undetected cases,' Kobinger said."
What Dr. Aylward says makes no sense and reads more like a PR fluff piece designed to praise China to keep them happy, and as Kobinger points out he's probably wrong. From the same press conference he says this "If I had COVID-19, I’d want to be treated in China."
He gives more detailed numbers about Guandong: at the height of the epidemic, they performed 320000 tests, of which less than 0.5% were positive, which means that they missed less than 200 cases. In other words, Aylward thinks the Chinese numbers are basically correct. Even though of course not all cases are detected, we are not looking at magnitudes more undetected cases driving up the infections in the background.
>320000 tests, of which less than 0.5% were positive, which means that they missed less than 200 cases
That doesn't follow from your premise and it doesn't match what he said.
"Of 320,000 tests performed, just under 0.5% were positive for the virus at the peak of transmission there, he said — which suggests that only 1 case out of 200 was being missed."
And even based on what he said the conclusion he's drawing doesn't follow either. From other sources the 320,000 was from a community sample. Guangdong has a population of 113 million, a 0.5% infection rate is over half a million people.
Even assuming it's not a random community sample, and it's from people who self selected, so the infection rate is much higher than the general population, there is still room for an order of magnitude more mild cases than are showing up in official numbers.
