If respiratory diseases were not complicated enough before COVID-19, this fall may be the example of peak complexity as atypical infectious disease seasons threaten to become the new normal and COVID-19 continues to mutate. The good news is that labs have a broad menu of assays to choose from. The challenge is making the right choices in advance to be prepared for the anticipated respiratory infections, including COVID-19, influenza, and respiratory syncytial virus (RSV).
The last couple of years have shown that we can no longer easily predict when the next surge of COVID-19, RSV, or flu will occur. The medical community has become so used to testing for COVID-19 for respiratory symptoms that they may overlook testing for the other important respiratory pathogens. Fortunately, many institutions have highly accurate forecasting models for respiratory pathogens that can enable manufacturers and laboratories to plan accordingly.1,2
Looking ahead based on the models and disease burden outside of the United States, infectious disease experts are predicting a high burden of influenza this upcoming fall and winter season, in addition to high rates for SARS-CoV-2 and RSV. Due to public health interventions such as social distancing and mask wearing, which prevented normal circulation of flu and RSV, there is now a larger susceptible population to these infections.3,4 Finally, as SARS-CoV-2 continues to mutate and novel variants, such as the Omicron variants circulate, we will continue to see high rates of COVID-19 in the United States.
Laboratories, clinicians, and patients have multiple types of testing to diagnose these different respiratory infections. During the COVID-19 pandemic, there have been increasing numbers of assays available including rapid antigen tests (for laboratory, clinic, and at-home testing), high throughput PCR and point-of-care PCR tests. Rapid antigen tests and PCR tests both have value when it comes to managing the pandemic; however, there are advantages to both in certain situations. We know that COVID-19 antivirals are most effective when given early on with symptomatic patients.5 In these situations, we should encourage the use of more sensitive, gold standard PCR testing to ensure patients receive the most accurate result early enough to start treatment for greatest effectiveness.
After treatment and once symptoms subside, a negative antigen test — even an at-home test — can enable patients to feel confident to resume normal ways of living. Point-of-care testing, including PCR and rapid antigen tests, allow physicians and patients to get rapid answers when larger scale testing is not available. With the complexity of this upcoming respiratory season, using panels, or PCR assays that can detect more than one pathogen, will be critical. These panels may include only two to three organisms, such as SARS-CoV-2, influenza, RSV, or they may be larger and include more than 15 different respiratory pathogens.
Conversations with clinicians in hospitals and the community are critical to ensure that optimal testing is available to meet all the needs of patients during this season. To meet the demands and uncertainty of this upcoming respiratory season, we should all be prepared sooner rather than later. Laboratories may need to plan to have access to multiple different assays and ensure coverage of different respiratory pathogens beyond SARS-CoV-2.
References
- CDC. FluSight: Flu forecasting. Centers for Disease Control and Prevention. Published April 13, 2022. Accessed August 5, 2022. https://www.cdc.gov/flu/weekly/flusight/index.html.
- Roche Diagnostics has an internal model for SARS-CoV-2 and influenza to ensure that adequate supplies of testing reagents are available when laboratories need them most.
- Baker RE, Park SW, Yang W, Vecchi GA, Metcalf CJE, Grenfell BT. The impact of COVID-19 nonpharmaceutical interventions on the future dynamics of endemic infections. Proc Natl Acad Sci USA. 2020;117(48):30547-30553. doi:10.1073/pnas.2013182117.
- Baker RE, Mahmud AS, Wagner CE, et al. Epidemic dynamics of respiratory syncytial virus in current and future climates. Nat Commun. 2019;10(1):5512. doi:10.1038/s41467-019-13562-y.
- CDC. Influenza antiviral medications: Summary for clinicians. Centers for Disease Control and Prevention. Published June 29, 2022. Accessed August 5, 2022. https://www.cdc.gov/flu/professionals/antivirals/summary-clinicians.htm
