Thread by @ASlavitt

COVID Update August 9: It’s time to talk about testing again.

Everyone thinks we are doing it badly and we are. Until we do we are not going to be close to back to normal. 1/

First of all we need tests for 3 different purposes.

-Confirming people are sick
-Testkng wear the outbreak goes
-Using tests to allow entry into buildings, schools & activities 2/

Tests to confirm people with symptoms are sick need to be quick turnaround time. We’re currently not doing that.

The only way there is to reduce cases and infection levels. The last 3 months have made it impossible. 3/

The PCR tests should be able to keep up with demand if we lower demand and if we specialize on using them for sick people.

Accuracy is important but it’s also time that PCR tests are required to meet a turnaround time standard. 4/

The second use for tests are to test asymptomatic people. These can be run at state labs, by health agencies and should be available everywhere.

The primary purpose for these tests should be to see where the virus is spreading so we can catch invisible cases and isolate. 5/

These tests need to be accurate but not as accurate as PCR tests. Mostly they need to be cheap and easy and not compete for the same resources— swabs & specialized reagents— as the first type of test. 6/

SalivaDirect is a roughly $5 test. It uses (you guessed it) saliva. And interchangable reagents.

Because these are asymptomatic people, they can be run in pools, another reason they can be done more cheaply. 7/

These tests can add millions to the stockpile of tests we can do each day. Even if they’re not perfect, they will help us fight the virus. 8/

Neither of these tests matter without two other things— isolation capabilities and contact tracing.

@DrTomFrieden will be on #inthebubble tomorrow. He has pioneered many of these approaches. 9/

Smarturl.it/inthebubble

One of the key things Tom points to is a place we are falling short and that is looking at some of the most important data.

How many positive cases are successfully isolated so they are terminal end the line cases? 10/

Across Europe with successful programs, that can be 60-70%. In the US most areas don’t even report that number, but in areas with high case count & limited to no contact tracing that can be as low as 2-5%.

We can’t improve until we can track & fix this. 11/

The third type of test is the type of test that we can use to enter buildings, offices, arenas, schools &!universities.

These tests ideally are self-administered, can be paper based (like a pregnancy test), done at home & not very expensive. 12/

These home based and event based antigen tests are going to be less accurate. They may cost $15 (they must be cheaper to be useful) and are a ways away from being approved in the US. 13/

This could work a variety of ways including:

Using a smart phone to read the color and also store so you could gain admissions places.

A reading device at an entrance.

A location like a CVS where you can go to get it read & carry the result with a time stamp. 14/

Are we ok with these being less accurate?

As @somuchweirdness points out in some ways it’s the equivalent of using a surgical mask. It maybe inferior to using an N95 but better than just having your breath meet the air. 15/

Because they are lower accuracy, you are setting up admission to a school or an event, it may best be used in combination with other NPIs like a mask.

No symptoms- rules out 60% of people
If a test were only 60% accurate, that would rule out another 25%
A mask another 10% 16/

So in combination you could enter an office or a school ruling out a 95% likelihood of being exposed. 17/

There are experts in each of these things.

@NathanGrubaugh has led the work on the second type of test.
@michaelmina_lab knows a lot about the third type of test.
@ashishkjha and @jhuber are expert at testing policy & innovation respectively 18/

https://twitter.com/nathangrubaugh/status/1292272724149182466

We need the cooperation of @US_FDA to get these tests approved with the APPROPRIATE level of sensitivity. Ie— don’t expect an entrance test to be as accurate as a hospital test.

People frequently ask what they can do to help. This website is one way.19/

rapidtests.org

We are still in early innings. Tests are game changers. Imagine if by January we had an abundance of all 3 of these types of tests. Plus we’re isolating & tracing.

Here’s what would happen. 20/

-School wouldn’t be in question.
-We would have no testing backlog
-Anyone could get a test any time
-We could all feel safe going places
-Contact tracing would be easy given the frequency of testing
-Economic activity

AND we would be reducing the spread & saving lives. 21/

And people in high risk jobs, nursing homes and communities on the margins would be much much safer. 22/

In combination with vaccines & therapies, mask wearing & safe habits, you can imagine life returning closer to normal. /end