Yesterday’s nucleic acid test indicated that there are new infections in our building. Ten samples were mixed in one test tube, so today these ten people will be retested separately. Our building has been under strict lockdown for three weeks. I have absolutely no idea how the newly infected people got infected. 

If such strict control measures are taken and the infection still cannot be prevented, what is the point of the control measures?

The popular explanation is that food delivery is the biggest source of infection during the lockdown. But is this believable? There are no official clarifications. But here’s a Q&A from WHO’s website:

Can the virus that cause Covid-19 live on the surface of food packaging?

Coronaviruses need a live animal or human host to multiply and survive and cannot multiply on the surface of food packages. It is not necessary to disinfect food packaging materials, but hands should be properly washed after handling food packages and before eating (see question 10 of Questions relating to food businesses). 

If you believe what the WHO said, food delivery should not be blamed. But why Shanghai still has so many new infections everyday? Today’s statistics is 17,629.