This figure shows the all-time average of each country’s daily positivity and daily tests conducted per capita. The size of the circles indicates the size of the epidemic in each location. Ideally, countries would have small circles and low positivity (below 5% per WHO recommendations).
This page was last updated on Wednesday, July 8, 2020 at 05:59 AM EDT.
The U.S. has conducted more COVID-19 tests than any other country. However, there is no expert consensus on a recommended target for the raw number of tests or even the rate of tests per capita – and the graph above demonstrates why using these statistics alone can be misleading.
In order for governments to identify new cases and effectively respond to the pandemic through tracing and treatment, testing programs should be scaled to the size of their epidemic, not the size of the population. In this visualization, you’ll see that several countries effectively controlled the spread of the virus through testing programs that had a far lower number of tests per capita than the U.S. Meanwhile, despite having the highest rate of tests per capita, the U.S. faces the largest outbreak in the world and new cases continue to trend upwards in many states.
Looking at the positivity rate (ie, out of all tests conducted, how many came back positive for COVID-19) is the most reliable way to determine if a government is testing enough. A high rate of positive tests indicates a government is only testing the sickest patients who seek out medical attention and is not casting a wide enough net. The WHO has issued guidance stating that governments should see positivity rates below 5% for at least 14 days before relaxing social distancing measures.