This indicates about 148,000 people in England could be currently infected - 0.27% of the population.
Imagine trying to trace the contacts of that many.
And, of course, while the survey suggests there are 148,000 infected people out there, it doesn't tell us who they are.
Remember, though, the best estimates are millions of people have had the coronavirus.
And this study tells us only about how many have it right now - and so can pass it on.
The 5,000 households tested in this survey did not include hospital patients or people living in care homes, where rates of Covid-19 are likely to be much higher.