Needless to say, Iceland’s efforts are revealing fascinating and potentially lifesaving details about the virus. And via BuzzFeed News, it’s how they came to the striking conclusion about symptom rates, emphasis ours:

“Early results from deCode Genetics indicate that a low proportion of the general population has contracted the virus and that about half of those who tested positive are non-symptomatic,” said [Iceland’s chief epidemiologist Thorolfur] Guðnason. “The other half displays very moderate cold-like symptoms.”

Consider: Right now, in America, if you don’t have a fever, or aches, or any other cold or flu-like symptoms, nobody would tell you not to go to the store. Nobody would tell you not to leave your apartment. Unless you had been in contact with someone who tested positive, showed symptoms, or to an epicenter of the outbreak, nobody would advise you to self-quarantine. Because nobody would be advising you to quarantine, you could still be spreading the virus to other people — and of course, in any of those places, other people who should be quarantined could be spreading the virus to you.

This is the value of widespread testing.