Coronavirus testing: Which countries are leading?

Authorities in many countries are grappling with how to slow the spread of the coronavirus. Though it’s impractical to test every potential patient, without testing it’s difficult to know how widespread is the outbreak.

Actions by countries have varied and shifted over time. Here’s how the data compare.

Tests per million people

Different approaches to testing

The United States and South Korea detected their first cases on the same day.

But South Korea’s swift action stands in stark contrast to what has transpired in the United States. Seoul quickly authorized and increased additional tests, while U.S. officials got bogged down in the rules approving tests and initially recommended tests only when a person had recently been to a hot spot or had contact with someone known to be infected.

But there have been other approaches to testing.

Italy started out testing widely but then narrowed the focus so authorities don’t have to process hundreds of thousands of tests. But there’s a trade-off: They can’t see what’s coming and are trying to curb the movements of the country’s entire population of 60 million people to contain the disease.

Meanwhile, Japan is only using a sixth of its capacity even as it is increasing its ability to do so, government data shows.

Japan’s health ministry has been focusing on clusters of cases, with the biggest around the megacities of Osaka and Tokyo, and in the prefectures of Hyogo, Hokkaido and Aichi. But with the rate of testing low, unseen clusters may be emerging elsewhere in the country.