The Observatory: We Need a New COVID-19 Testing Strategy
The Observatory is a new weekly series that brings together students, alumni, and professionals associated with OSU Battelle Center to write about topics that are relevant to the mission of our center. Our guest writer this week is Kaitlin Hamilton, a doctoral candidate in Dr. Amal Amer’s Lab in the Department of Microbial Infection and Immunity at The Ohio State University. Her research interests include investigating how mitchondria regulate the immune system in order to identify new mitochondrial-based therapies for immune system disorders.
Coronavirus testing in the United States has been fraught with issues since the pandemic took hold in March. The gold-standard test uses reverse transcription-polymerase chain reaction (RT-PCR) to amplify and detect viral RNA obtained from a deep nose swab sample. Although this test is extremely sensitive, it has been difficult to ramp up production for widespread usage due to persistent supply shortages. Several public health experts, including Dr. Ashish Jha, director of Harvard’s Global Health Institute, have estimated that the United States needs to perform several million tests per day in order to adequately track the virus. However, the United States only hit one million tests per day just this past month. Two of the largest COVID-19 testing labs, Quest Diagnostics and LabCorp, are reporting average test turnaround times of one to two days. While this is an improvement over the three to four days reported over the summer, the ideal turnaround time would be a matter of minutes so that infected individuals can be quickly identified and quarantined. Delayed results increase the amount of time that potentially infected people interact with others, which can enhance the spread of the virus.
To address these testing issues, there is a push to develop cheaper coronavirus tests that are easier to manufacture and have a faster turnaround time. One well-publicized test is Abbott’s BinaxNOW. This $5 test involves inserting a nasal swab onto a credit card-sized test card to detect viral antigens in 15 minutes. Following an Emergency Use Authorization by the FDA in August for symptomatic individuals, the federal government announced in September that it would be purchasing 150 million tests to distribute throughout the country, including Ohio. Another nasal swab-based test by E25Bio that takes 30 minutes is also undergoing FDA review. Alternatively, researchers at Columbia University and the University of Wisconsin-Madison are seeking FDA authorization for tests that utilize saliva samples. These tests involve incubating saliva with a reaction mixture for 30 minutes. If the color of the mixture changes from red to yellow, then viral RNA has been detected in the sample.
The adoption of these rapid coronavirus tests has been slow due to concerns that they are not as sensitive as the gold-standard RT-PCR test and will result in false negatives. However, several recent studies have found that reducing test turnaround time was more important in limiting viral spread than test sensitivity. If people can be tested more frequently, perhaps weekly or even daily, then a rapid test that is not sensitive enough to catch them one time may catch them the next time when their viral loads are slightly higher. By using less sensitive tests with a fast turnaround time instead of more sensitive tests with a slow turnaround time, we can switch our approach to coronavirus testing from a diagnostic one that focuses on individual patients to one that is capable of screening large amounts of people on a regular basis. The coronavirus is still going to be an issue well into 2021. Adopting a screening-based testing strategy in combination with other preventative measures, such as mask-wearing and physical distancing, will help us to slow the spread of this devastating virus and more safely return to work and school.
