Pooled testing may conserve costs and supplies

July 22, 2020
In an effort to reduce the time and costs associated with individual COVID-19 tests, as well as meet increased test demands, governmental agencies are looking into additional testing options that can provide more results and less cost at the same time. Currently, pooled testing, also called herd testing, is the test method being considered as one of the most promising options to detect exposure to COVID-19, which is caused by the SARS-CoV-2 virus strain. As one of the primary benefits of pooled/herd testing, scientists have the ability to test small groups of people at one time, versus being forced to test each individual person in a specific and/or suspected group that may have been exposed to COVID-19.

Another advantage of pooled testing lies in its convenience factor as it allows for multiple samples to be mixed together and run as one test. For example, if scientists need to test 100 people, they can divide the total into two much smaller groups of 50 and then have each groups’ included members contribute samples. If the final amalgamated test result comes back negative, then all the people who contributed samples to that test run are assumed to have a negative result as well – which could effectively rule 50 people negative for exposure to COVID-19 at once.

However, if the combined sample evidences a positive result, then those sample contributors would be tested further to identify the person who may be asymptomatic but still infected with COVID-19. While positive-result pooled testing still requires additional tests, it still offers the option of being able to eliminate the time and costs related to staff and supplies for all the people who will not need to be retested because their samples contributed to the negative-result test run.

On the topic of pooled testing, Anthony Fauci, MD, Director of the National Institute of Allergy and Infectious Diseases (NIAID), said “health officials are considering pooled testing for COVID-19 in response to the recent surge (of U.S. cases).” He said pooled testing may not be the best or most cost-effective testing option in every situation, as pooled testing works best with smaller groups that need testing. But as larger numbers of people will require a larger number of groups, this may create larger numbers of positive results and the potential for more people who need additional testing. All of this testing would defeat the time saving and cost-effectiveness of pooled testing as it is intended.

With millions of COVID-19 tests performed and cases diagnosed, at times it can still prove challenging to find a consensus of opinion on the best way to address best practice testing for the disease. There is no easy answer except to perform more testing, which includes existing testing methods that are used as strategic surveillance tools, as well as whatever testing options the clinical lab industry comes up with next to meet continued demand. Its only through accurate and reliable testing that we afford ourselves a better chance to get better prepared for the arrival of the next pandemic.

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