ADADBut a closer look at the state of testing in the United States shows that this theory is dangerously wrong. It is true that the United States has dramatically expanded testing for the virus that causes covid-19. At the beginning of April, when testing was constrained at around 20,000 tests per day, positivity reached a peak of 50 percent. That’s the pattern health officials would like to see in testing, but it is not the prevailing pattern across the United States. ADADOverall test positivity in the United States has fallen dramatically (partly because we tested so few people early on).