Hello and welcome to more or less on the BBC World Service, the program all about the numbers

all around us in the news and in life. I'm Tim Haferd.

This week we're digging into the data behind the recent rise in COVID-19 cases in the

United States.

And so I am very concerned if you look at the curves of the new cases, clearly we are not

in total control right now.

Once Dr Anthony Fauci, Director of the US National Institute of Allergy and Infectious

Diseases, speaking to the Senate Health Committee on Wednesday. On that day the US announced 52,000

new coronavirus cases up from 44,000 the day before the highest number of cases confirmed

in a single day so far in the US. It certainly sounds concerning, but not everyone is as worried

as Dr Fauci.

Testing is a double-edged sword. We've tested now 25 million people. Here's the bad part.

When you do testing to that extent, you're going to find more people, you're going to find more cases.

So I said that my people slow the testing down please.

President Trump's claim is that there aren't really loads more people with COVID. They're

just getting very good at finding the cases that do exist. And it is true that testing

in the US has been increasing. Over the last week they've been doing about 500 to 600,000

tests per day up from about 100,000 a few months ago. But to understand if there really

are more cases or just more cases being identified, it's important to also look at the proportion

of tests, the depositives. If you ramp up testing and the positivity rate falls, then maybe

the rise in cases is just because of the rise in tests. But when I spoke to Dr. Waffer

El Sada, professor of epidemiology at Columbia University's School of Public Health in New

...