Coronavirus testing helps to prevent the community spread of the pandemic - more is better!

This echo essay was written by Ronald R. Fricker, Jr., and it was published in The Conversation. 

As the need for testing has grown, so have lines at testing facilities. Results can take more than a week to be returned. This is unacceptable. Regardless of how many people are tested, if the results are not provided in a reasonable time frame then the results are almost irrelevant. 

More tests do not correlate to more coroavirus.  Instead, more tests help to determine where the clusters of coronavirus are being transmitted so that contact tracing can help to isolate and protect the increasing community spread of the pandemic.  Tests do not cause the coronavirus. A virus causes the COVID-19.  Finding where the disease is clustered will help public health professionals to isolate the outbreak.

Although the Johns Hopkins tracking data reports that the U.S. has processed more coronavirus tests than any other country in the world, there is no expert consensus on a recommended target for the raw number of tests or even the rate of tests per capita . 

Yet, at the same time, the U.S. is notably underperforming in terms of suppressing COVID-19. 

Confirmed cases – as well as deaths – are surging in many parts of the USA. Some people have argued that the increase in cases is solely due to increased testing.

I am a statistician who studies how mathematics and statistics can be used to track diseases. The claim that the increase in cases is only caused by increases in testing is just not true. But how do public health officials know this?
Testing, confirmed cases and total cases

COVID-19 testing has two purposes. The first is to confirm a diagnosis so that medical treatment can be appropriately rendered. The second is to do surveillance for tracking and disease suppression – including finding those who may be asymptomatic or only have mild symptoms – so that individuals and public health officials can take actions to slow the spread of the virus.

At a White House briefing on July 13, the president said, “When you test, you create cases.”

The problem with this statement is that anyone who is infected with the coronavirus is, by definition, a case. Since taking a COVID-19 test does not cause a person to get coronavirus, just like taking a pregnancy test does not cause one to become pregnant, the president’s claim is false. Testing does not create cases.

However, because many COVID-19 cases are asymptomatic, many people are infected and don’t know it. What COVID-19 testing does do is identify unknown cases. And thus it does increase the number of cases that are known, or otherwise called the confirmed case count.

Finding unknown cases is good, not bad, because identifying those who are COVID-19-positive allows individuals and public health officials to take actions that slow the spread of the disease. When public health officials find cases, they can begin contract tracing. When a person finds out they are infected, they will know to quarantine.

Since the beginning of the pandemic, the U.S. has performed more total tests and more tests per capita than any other country, though as of late July the U.K., Russia and Qatar were performing more tests per capita per day. But counting the total number of tests or the tests per capita is not the right way to judge success of a testing program.

As it says on the Johns Hopkins testing comparison page, a country’s “testing program should be scaled to the size of their epidemic, not the size of the population.” Sure, the U.S. might have a big testing program, but it has a massive epidemic. The U.S. needs an equally massive testing program if health officials want to have an accurate picture of what’s really going on.

The U.S. has performed more coronavirus tests than any other country in the world. Yet, at the same time, the U.S. is notably underperforming in terms of suppressing COVID-19. Confirmed cases – as well as deaths – are surging in many parts of the country. Some people have argued that the increase in cases is solely due to increased testing.

I am a statistician who studies how mathematics and statistics can be used to track diseases. The claim that the increase in cases is only caused by increases in testing is just not true. But how do public health officials know this?

Testing, confirmed cases and total cases

COVID-19 testing has two purposes. The first is to confirm a diagnosis so that medical treatment can be appropriately rendered. The second is to do surveillance for tracking and disease suppression – including finding those who may be asymptomatic or only have mild symptoms – so that individuals and public health officials can take actions to slow the spread of the virus.

At a White House briefing on July 13, Donald Trump said, “When you test, you create cases.” (Maine Writer- Pinocchio!)

The problem with this statement is that anyone who is infected with the coronavirus is, by definition, a case. Since taking a COVID-19 test does not cause a person to get coronavirus, just like taking a pregnancy test does not cause one to become pregnant, the president’s claim is false. Testing does not create cases.

However, because many COVID-19 cases are asymptomatic, many people are infected and don’t know it. What COVID-19 testing does do is identify unknown cases. And thus it does increase the number of cases that are known, or otherwise called the confirmed case count.

Finding unknown cases is good, not bad, because identifying those who are COVID-19-positive allows individuals and public health officials to take actions that slow the spread of the disease. When public health officials find cases, they can begin contract tracing. When a person finds out they are infected, they will know to quarantine.

Since the beginning of the pandemic, the U.S. has performed more total tests and more tests per capita than any other country, though as of late July the U.K., Russia and Qatar were performing more tests per capita per day. But counting the total number of tests or the tests per capita is not the right way to judge success of a testing program.

As it says on the Johns Hopkins testing comparison page, a country’s “testing program should be scaled to the size of their epidemic, not the size of the population.” Sure, the U.S. might have a big testing program, but it has a massive epidemic. The U.S. needs an equally massive testing program if health officials want to have an accurate picture of what’s really going on.