By Anders Gundersen, HGH | March 11, 2020
Confusion and controversy have surrounded the conversation about diagnostic testing for COVID-19 in the United States. We know that testing is a critical component of an effective response effort. We summarize a recent JAMA viewpoint that highlights why the US has experienced a testing gap, walks through the regulatory procedures for lab-developed tests during an emergency, and provides some insight into who should be tested.
JAMA | Sharfstein et al. | Mar. 9, 2020Why was there a testing gap?
Rather than using the test adopted by the WHO, the CDC developed its own diagnostic test, which could bypass FDA approval through and emergency use authorization (EUA)
They shipped it to labs nationwide, but it was flawed and the results it provided were therefore unreliable. It wasn’t until February 29th that the FDA permitted state labs to develop and use their own tests
Understanding the regulatory domain.
The FDA is normally not involved in the regulation of lab-developed tests. This changes during emergencies.
The FDA chose to only allow distribution of the CDC-developed test
The flaw in the CDC’s test exposed the risks of this strategy:
Inadequate capacity to conduct surveillance
Challenges in scaling up quickly for broad clinical care
Quickly identifying any errors in state-developed tests will be critical
Who should be tested?
Those who are currently considered to have high priority for testing:
Patients with serious, unexplained respiratory illness and contacts of known cases
Widespread testing comes with its own risks:
Overwhelming medical services
Further spread of the disease to people seeking testing who may not already be infected
Negative results do not rule out infection due to the potentially long incubation period
Testing is not a substitute for other preventive measures, such as handwashing, isolation, and social distancing