2 ms·

This will be important information in a few months when countries have lowered the new detected cases and the lift of harsh measures is considered. So there is

This will be important information in a few months when countries have lowered the new detected cases and the lift of harsh measures is considered. So there is still some time to get the data. At the current moment, they are not important for the decisions. However I want to caution anyone to expect a large proportion of the population to test positive in these tests. We know that South Korea was able to contain the spread before a significant proportion of the population was infected. A important part of the strategy was contact tracing. For contact tracing to work, you need to detect at least 1-1/R of cases. If we assume that other measures such as masks and limited social distancing pushed R down to 2 and assume they were able to trace 100% of contacts, then we still have only twice as many that are infected. If nobody of the cases that are still ongoing dies, we look at a lower bound of the IFR of 0.8%.

nostrebored 7y ago
How can you say this? If it's significantly more infectious than we thought, that will obviously influence public policy as the r_0 will be radically decreased
- xorfish 7y ago
  The number of people that are infected doesn't tell you that much about R0. You can get R0 from the increase in daily new deaths and the generation time between infections, given that the quality of care stays constant. Serological tests will tell you something about the early outbreak and how many cases where not detected and how high the infected fatality ratio really is. I have seen many people that still believe that the IFR is in the range of an average flu. With the data from South Korea, we can put a number at what we can expect the IFR to be if we make some optimistic assumptions. That is why I say that you should not expect that serological tests show that a large part of the population already had covid19 and that the IFR is much lower than we expect. They will show where exactly the IFR is.

nostrebored 7y ago

How can you say this? If it's significantly more infectious than we thought, that will obviously influence public policy as the r_0 will be radically decreased

xorfish 7y ago
The number of people that are infected doesn't tell you that much about R0. You can get R0 from the increase in daily new deaths and the generation time between infections, given that the quality of care stays constant. Serological tests will tell you something about the early outbreak and how many cases where not detected and how high the infected fatality ratio really is. I have seen many people that still believe that the IFR is in the range of an average flu. With the data from South Korea, we can put a number at what we can expect the IFR to be if we make some optimistic assumptions. That is why I say that you should not expect that serological tests show that a large part of the population already had covid19 and that the IFR is much lower than we expect. They will show where exactly the IFR is.