If we're going to manage a #TestTraceIsolate solution to the #COVID19 epidemic, we need a massive scale up in testing. There are some really exciting initiatives here. 1/9
According to @COVID19Tracking, the US is managing roughly 150k tests per day at this point. These 150k tests are finding about ~30k confirmed cases each day. However, I believe based on modeling results and serology that these have a 10-20X underreporting rate. 2/9
This would translate to between 300k and 600k new infections per day. This means roughly 2 to 4 times as many new infections per day as there are tests being conducted. This heavily limits case-based interventions where identifying confirmed cases is a prerequisite. 3/9
In order to have this necessary testing scale up, we need to improve both logistics around specimen collection as well as throughput of specimen screening. 4/9
On the specimens side, recent work by @SRsrivatsan, @lea_starita, @JShendure and colleagues has shown that shipping dry swabs in the mail works without compromising sensitivity of the assay. 5/9
Work by @awyllie13, Albert Ko, @NathanGrubaugh and colleagues has shown that saliva specimens appear more sensitive than the significantly more invasive nasopharyngeal (NP) swabs. 6/9
On the screening side, recent work by @TomerHertz and colleagues pools multiple samples together in overlapping combinations and works out positive samples based on which combinations show as positive, resulting in an 8X efficiency boost. 7/9
Work by @srikosuri and colleagues amplifies RNA with a unique barcode to each sample, pools and uses sequencing to detect which samples have #SARSCoV2 present. This dramatically increases throughput relative to RT-PCR but at the cost of some latency. 8/9
For #TestTraceIsolate to have a large impact on reducing transmission, this strategy requires testing to be readily available for mild cases that would not other seek clinical care. We need innovative strategies to make this possible. 9/9
