Laboratory testing plays a crucial role in the response during an emerging infectious disease outbreak. Lives can be saved by an early and effective laboratory testing response. Specific to the COVID-19 pandemic, laboratories are having to get creative and use every tool in their toolbox to provide the caliber of service the profession has historically built its reputation upon.
Testing Trials & Tribulations
SARS-CoV-2 is a novel virus that causes the coronavirus disease 2019 (COVID-19). Regrettably, testing for SARS-CoV-2 in the U.S. has been riddled with problems and roadblocks right from the start. Missing the opportunity to start testing with the WHO test, followed by contamination issues with the CDC-developed tests set the U.S. off to a rocky start in its pandemic response. These early mis-steps, combined with shortages of vital supplies like NG swab, reagents, and PPE, have not made it easy for laboratories to address the increasing demand for testing.
Testing Takes on Many Methodologies
There are several categories of testing available, each with different clinical utility, specimen requirements, characteristics, and limitations. The preferred testing methodology for acute infection is reverse transcription polymerase chain reaction (RT-PCR), a molecular test. Antigen tests are also used to diagnose an active infection; however, their lesser sensitivity requires that negative test results for symptomatic patients are confirmed with a molecular test.
There are also serological or antibody tests available that can help determine exposure history and immune status. However, there is much controversy around how accurate serological tests are at predicting immunity and whether patients can be re-infected. We are still learning about this virus. To try and overcome barriers, many laboratories are testing on more than one platform and many are realizing the value that rapid POCT can add as these tests come onto the market.
The Need for Speed
Unfortunately, because of the complexities surrounding testing and other barriers, TATs are not fast enough to allow for efficient contact tracing and disease containment. And, testing demand continues to increase, driven by:
TATs are reported to be between three to five days at large reference laboratories and up to 14 days at smaller laboratory sites. Delays in testing mean public health workers are not able to notify the contacts of people who test positive, so people unwittingly continue to spread the virus.
“If you're going to do contact tracing and the test comes back in five to seven days, you might as well not do contact tracing because it's already too late.”
- Dr. Anthony Fauci, National Institute of Allergy and Infectious Diseases
Each of the test methodologies (molecular, antigen, and antibody) is available in a rapid POCT format. While laboratorians are acutely aware of the limitations of POCT regarding sensitivity and specificity, in some cases, there is a significant advantage gained by rapid turnaround (TAT), making the trade-off worthwhile.
“Coronavirus tests administered outside lab settings are considered useful in fighting the pandemic even if they miss 20% of positive cases.”
- Senior FDA Official
POCT as a Tool to Help Take Care of the Elderly
Of particular concern is the elderly population living in nursing homes where there have been more than 200,000 COVID-19 cases and more than 35,000 deaths among residents as of early July. To address this problem, the Department of Health & Human Services (HHS) announced large-scale procurement of FDA-authorized rapid diagnostic POCT to be distributed to nursing homes (starting in COVID-19 hotspots) to help prevent the spread of SARS-CoV-2. The CDC recommends on-site baseline testing of all residents and staff, including regular screening and surveillance to detect potential outbreak situations early and reduce morbidity and mortality.
“POC tests are a useful component of the diagnostic strategy in response to the SARS-CoV-2 (COVID-19) outbreak.”
- Office of the Asst Secretary for Health SARS-CoV-2 Fact Sheet
Laboratories as the First Line of Defense
If there was ever a time to be proud to be a Medical Laboratory Scientist/Medical Technologist, now is the time. Clinical laboratories are often the first line of defense in a pandemic response and laboratory professionals play a critical role in helping to contain the virus.
In the current evolving crisis, with its complexities and curveballs, many labs are implementing multiple testing methodologies that include rapid POCT as a comprehensive way to meet the testing demand. It is also of great benefit, particularly in light of HHS reporting requirements, to have as much testing as possible electronically integrated.
In addition, with the laboratory now in the public eye more than ever before, this opens an opportunity for laboratorians to educate and be leaders in the effort to gain ground on this life-changing pandemic.