The test-positivity rate, then, is a decent (if unusual) proxy for the severity of an outbreak in an area. And it shows clearly that the U.S. still lags far behind other countries in the course of fighting its outbreak. South Korea—which discovered its first Coronavirus case
on the same day as the U.S.—has tested
more than half a million people, or about 1 percent of its population, and discovered about 10,500 cases. The U.S. has now tested 3.2 million people, which is also about 1 percent of its population, but it has found more than 630,000 cases. So while the U.S. has a 20 percent positivity rate, South Korea’s is only about 2 percent—a full order of magnitude smaller.
South Korea is not alone in bringing its positivity rate down: America’s figure dwarfs that of almost every other developed country. https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection.html,
Germany and
Denmark have positivity rates from 6 to 8 percent. https://www1.health.gov.au/internet/main/publishing.nsf/Content/1D03BCB527F40C8BCA258503000302EB/%24File/covid_19_australia_epidemiology_report_10__reporting_week_ending_23_59_aest_5_april_2020.pdf and
New Zealand have 2 percent positivity rates. Even Italy—which faced one of the world’s most ravaging outbreaks—has a 15 percent rate. It has
found nearly 160,000 cases and conducted
more than a million tests. Virtually the only wealthy country with a larger positivity rate than the U.S. is the United Kingdom, where
more than 30 percent of people tested for the virus have been positive.