No it doesn't. But what you ultimately want to know is the real number of infections. Testing is the best way to estimate that number. If you test just a few pe

No it doesn't. But what you ultimately want to know is the real number of infections. Testing is the best way to estimate that number. If you test just a few people you might e.g. miss a large portion that is either asymptomatic or is categorized as having a flu or cold. In this latter case, of course, the calculated lethality is higher than in the former - i.e. if you test lots and lots of people.