A) You'll know which communities have infections. Many places are saying: "it's not bad here, why should we isolate?" B) If you know that someone with bad symp

A) You'll know which communities have infections. Many places are saying: "it's not bad here, why should we isolate?" B) If you know that someone with bad symptoms has the virus, then you can go test everyone they contacted. You'll find more people who currently have mild or no symptoms.