Making Informed Testing Decisions for Respiratory Illness: Insights from Jeb S. Teichman, MD and Jamie P. Deeter, PhD

We are republishing a blog post originally shared on Family Fighting Flu's website. This piece underscores the importance of testing as flu season approaches, resulting from a collaboration between CLSI, Families Fighting Flu (FFF), Roche's Dr. Jamie Deeter – a longtime and valued CLSI volunteer and contributor - and Dr. Jeb Teichman.

Not sure which respiratory test to use? It all comes down to the medical value, said Dr. Jamie P. Deeter, a molecular virologist at Roche Diagnostics who specializes in coronaviruses and has helped bring multiple EUA SARS-CoV-2 diagnostic tests to market. We asked Dr. Deeter and Dr. Jeb Teichman, a pediatrician with decades of experience and director and medical advisor for Families Fighting Flu, to talk about the importance of testing for respiratory illnesses like flu, COVID, and respiratory syncytial virus (RSV) and the information health care providers need to make informed testing decision for respiratory illness.

Is it really necessary to test for flu or other respiratory viruses? Isn’t it standard practice to treat based on symptoms?

JD: Empirical diagnosis, or diagnosing based on symptoms alone, is very difficult due to the overlap in symptoms caused by SARS-CoV-2, influenza, and RSV. Testing should be utilized for optimal patient outcomes and to ensure appropriate use of antibiotics and antivirals.

JT: Absolutely! A “test to treat” approach is the best way to keep both patients and those who they encounter, healthy. We know that combining best practices of early detection with ready access to treatment slows and, in some cases, prevents disease progression in individuals and their communities.

Pre-COVID pandemic, we only had antivirals for Influenza, and years ago, the tests were not that good. Now the available tests are much more accurate, and we have other respiratory illnesses with similar symptoms. Standard practice is not to treat based on symptoms anymore, because the symptoms are similar across several respiratory viruses. Testing is paramount in determining the correct treatment. Families Fighting Flu highlights this need through personal stories of individuals who have had a range of negative outcomes from contracting influenza.

Should all patients be tested? If yes, what is the significance of the data collected from a healthcare and public health perspective?

JT: No, only symptomatic patients need to be tested. If we talk about the flu, the CDC and local health departments collect the data through their sentinel program, which I was part of, where the CDC gets a lot of the data for flu surveillance.

What are the benefits of both treating and testing?

JT: “Treat to test” The benefit of testing is obtaining the correct diagnosis to assign correct treatment and improve outcomes. With flu, the timing of testing is important. By day 5 of the flu, most people have recovered, but others are hospitalized; therefore, it is critical to test within the 48-hour window.

What are the different types of tests available?

JD: There are two types of tests typically utilized for detecting respiratory pathogens: molecular tests and antigen tests. These tests are named after the part of the virus they are detecting. However, understanding which test to use for your patients all comes down to medical value: where the testing is performed and who (age, comorbidities, previous infections, etc.) needs the tests.

As the protocol for annual flu, COVID, and RSV vaccinations becomes more established, how will it impact the role of testing in managing these illnesses?

JD: Combating respiratory pathogens is a three-pillar strategy: prevention, testing, and treating. Prevention starts with vaccination. However, vaccines do not have 100% efficacy. Thus, when someone is symptomatic or needs a negative test to ensure they will not expose someone who is in a vulnerable population to a pathogen, diagnostics tests should be utilized. Diagnostics need to be utilized in a timely manner to ensure the appropriate patient management and therapy can be given, as many antivirals are only effective if given within 24-48 hours of symptom onset. Understanding the diagnostic testing landscape for respiratory pathogens can be difficult. However, the Clinical and Laboratory Standards Institute published a white paper, POCT18 ED1— Selection Process for CLIA-Waived Testing for SARS-CoV-2, Respiratory Syncytial Virus, and Influenza Virus, to aid with understanding:

• The different testing modalities that are available in a CLIA-waived setting.
• How the results and performance of the test should be interpreted.
• The points that should be considered when health care providers are determining which type of test is best for their patient (testing location, patient population, and appropriate use of tests).

In summary, the whitepaper provides critical guidance for healthcare providers in choosing the best test for the patient’s needs. CLSI’s library of standards and guidelines for point-of-care testing is a valuable resource for clinical professionals, who are increasingly turned to as a more convenient alternative to traditional lab testing.

JT: Remember that the goal of vaccination is to prevent hospitalization and death. People who are vaccinated can still get disease, so testing, even in the vaccinated, is important.

What information do patients and providers need to know about testing (eg, different types and benefits of rapid influenza diagnostic tests (RIDTs) and lab testing, molecular tests, antigen tests, etc.). What tools and resources are available?

JD: Providers have a responsibility to their patients when conducting diagnostic tests to understand the caveats of the specimens utilized for the tests, how the specimen should be handled, testing volume and throughput, how to interpret discrepant results should they occur, and what quality controls should be utilized. All of that is shared in detail in POCT18. This is an incredibly valuable document for healthcare providers who are not in a lab but are performing diagnostic testing such as in physician office labs, urgent cares, pharmacies, etc.

JT: This is a really complex issue that I’m not sure that patients can understand, and they need to leave that up to their providers. Now, education with the providers is important. This is what the CDC has been doing, educating the providers on the tests available and the pros and cons of each one. In the end, it’s PCR.

Where else can providers seek more guidance?

JD: There is a new Association of Diagnostics and Laboratory Medicine, Guidance Document on Laboratory Diagnosis of Respiratory Viruses that was just published in May 02, 2024, that is a wonderful resource.

(Citation: Berry GJ, Jhaveri TA, Larkin PMK, Mostafa H, Babady NE. ADLM guidance document on laboratory diagnosis of respiratory viruses. [Epub] J Appl Lab Med May 2, 2024, as doi: 10.1093/jalm/jfae010.)

JT: The CDC is a resource for just about everything and their publication, MMWR. All available online without a subscription. https://www.cdc.gov/mmwr/index.html.

Dr. Jamie P. Deeter holds a PhD in infectious diseases and currently serves as Senior Director for Scientific Affairs at Roche Diagnostics. She’s a biotechnology leader with over a decade of industry and laboratory experience.

Jeb S. Teichman, MD received his medical degree from the University of Louisville. He completed his residency in Pediatrics at the Children’s Hospital of Buffalo, State University of New York (SUNY) Buffalo. Dr. Teichman lost his 29-year-old son, Brent, to influenza in 2019 and is now a director and medical advisor for Families Fighting Flu. Brent’s story is featured here on the Families Fighting Flu website.