The Centers for Disease Control and Prevention (CDC) mass-produced a diagnostic test kit for the novel Covid-19 coronavirus in early February. After these testing kits were shipped, however, it was discovered that they were unreliable, with news reports indicating they contained a faulty reagent.

While waiting for replacement testing kits from the CDC, US commercial and state laboratories were not approved to use their own laboratory-developed test for diagnosing the coronavirus disease Covid-19.

A lack of effective in vitro diagnostic kits, combined with stringent testing criteria, meant that as of 1 March, the US had only tested 470 people for Covid-19. This is in stark contrast to other countries with much more effective testing regimens, such as South Korea, Italy, and the UK, which had tested 109,591, 23,345, and 13,525 people respectively. These testing statistics are even more staggering when put into the context of population size, with the US having between four and five times as many inhabitants as each of these individual countries.

Following heavy criticism, on 29 February, the FDA issued a new policy for diagnostic testing of Covid-19. This policy provided guidance for Clinical Laboratory Improvement Amendments (CLIA)-certified laboratories to develop and use their own Covid-19 diagnostic tests. On the same day, the FDA granted emergency use authorisations for Covid-19 tests to two public health laboratories in New York City.

The CDC has since also broadened its criteria for testing patients suspected of having the infection. Previously, the only people eligible for testing were those who had been exposed to a confirmed patient, travelled to a country with a known outbreak, or required hospitalisation. People with symptoms of the disease such as coughs and high fever are now also eligible for testing. Additionally, physicians are encouraged to consider the status of the coronavirus outbreak in their specific area when making a decision about testing.

The impact of the improved accessibility for US patients to Covid-19 diagnostic testing remains to be seen. While the situation is now improving, the extent to which this disease has already spread within the country remains unclear. Furthermore, experts are questioning whether laboratories will be able to handle the surge in demand that will result from the updated guidelines.