Duke Margolis researchers, along with Dr. Caitlin Rivers of John Hopkins University, have released a new issue brief on how we can improve our national testing strategy for COVID.
There are a couple of main points that we make.
- Develop Smarter Testing
The current testing regime is heavy on PCR tests which require skilled medical personnel, a complex lab and time. These tests are fairly expensive and potentially too slow to influence clinical and public health decision making. However, they are very specific and precise. If a PCR tests indicates that someone has COVID, they most likely do have COVID. This is needed for diagnostic purposes. We need more screening tests. These tests need to be faster and cheaper to run. The trade-off is that we should embrace more false positives as anyone who is screened as potentially positive should isolate while they receive a far more precise (albeit slower) PCR diagnostic test to get confirmation of either a true positive or cateagorize the screening result as a false positive.
Governor DeWine (R-OH) is a good example of how this system should work on a national scale. He was screened with a high speed, low cost antigen test that returned a positive signal. This shifted our prior on the probability of him being an non-symptomatic infected individual from unlikely to possible. And that change in priors led to a high value PCR test being used.
— Dr. Tara C. Smith (@aetiology) August 7, 2020
At the same time, as he was waiting for the PCR test results to come back, he changed his behavior. He isolated himself. Some of his close contacts (his wife) also isolated themselves. If he had been infected, his actions significantly reduced the window in which he could have infected anyone else. He got the screening test because he was scheduled to meet with the President. That is not a sustainable model of national screening, but massive scaling up of cheap and accurate enough testing can break infection chains before they get started.
- Increase testing capacity
Congress should appropriate $45 billion dollars to create a national testing system that is focused on high risk populations (nursing homes, congregate living situations, schools. These tests don’t need to be single PCRs. It could be antigen or pooled PCR or a variety of other other technologies and approaches. Routine screening is plausible for locally (temporally and geographically) high risk populations for a year and a half.
- Widen the Supply Chain
Use the Defense Production Act to resolve immediate supply chain chokepoints. The Department of Health and Human Services (HHS) should publicly publish end to end supply chain analysis of all critical technologies and supplies on a regular basis. Furthermore, HHS should engage in advanced purchase arrangements and subscription deals (similar to Hep-C antivirals) to produce investment certainty.
- Tracing and Isolating
Testing is the first part of the public health response. Testing allows us to identify who needs interventions to break infection chains. Tracing and Isolating are our dominant public health interventions. $24 billion dollars should be provided to fund the costs of sufficient contact tracers to smother outbreaks before they start, pay for hotel rooms for people who need to be isolated but can not be safely isolated at home, and provide some, limited, wage/income support for individuals who need to be isolated but don’t have the ability to take sick time from work.
HHS should publish standardized and appropriately stratified reporting on key testing, and isolating indicators at the minimum state level if not county level. This will allow for more granular epidemic responses by public health authorities.
Clear, concise and consistent communication by trusted messengers is key. We need to know current testing status, turn around times for results, and contact tracing capacity at local, state and national levels.