The Impact of Diagnostic Testing for Viral Respiratory Infections

Allie Priego, PA-C • Oct. 22, 2024

Viral respiratory infections are a significant public health problem due to the economic burden they create, as well as their association with morbidity and mortality. Respiratory tract infections accounted for 56 million deaths in 2019, representing the third leading cause of death worldwide.¹ The clinical presentation and spectrum of respiratory viruses can vary greatly, from mild cold symptoms to life-threatening conditions such as acute respiratory distress syndrome (ARDS) or community-acquired pneumonia (CAP).

Multiple studies have found that it can be difficult for a clinician to differentiate between viral and bacterial respiratory tract infections based on clinical presentation alone, which is where diagnostic testing can play a crucial role in better identification of these viruses. There have been many advances in diagnostics for viral respiratory illnesses, which has helped clinicians to make more informed and quicker diagnoses and treatment plans for their patients. Testing for respiratory viruses, even in healthy individuals or patients with mild symptoms, is important for several reasons:

By utilizing a respiratory viral panel, a clinician can know the specific virus affecting the patient, which can help guide treatment. If a clinician was considering presumptively treating a patient with respiratory symptoms for CAP, they may subsequently change the management of this patient and de-escalate antibiotic therapy in the presence of a positive respiratory viral test result, reducing unnecessary and prolonged antibiotic courses. One study showed an association between a positive test for Influenza A, Influenza B, and RSV, and subsequent reduction in the use of antibiotics in the pediatric population.²

Another study revealed that proper identification of the influenza virus can reduce the number of hospital admissions, the number of radiographs ordered, the hospital admission length, and duration of antibiotic therapy.³  An additional study found that there was no association found between a prescription for antibiotics and patient satisfaction; however, patient satisfaction did correlate with the patients’ report that they understood the illness.⁴ These insights suggest that patient satisfaction does not necessarily improve with a prescription for antibiotics, but rather that the patient feels that they understand their illness. Viral respiratory testing can help identify these infections so that the patient better understands their illness.

By confirming a respiratory illness is viral, healthcare providers can focus on supportive management and patient reassurance rather than exposing the patient to unnecessary antibiotics. One study found that among ambulatory care patients being treated for upper respiratory infections, patients’ most important goal was to obtain a diagnosis.⁵ Respiratory testing can help solidify a diagnosis for patients as well as provide more targeted expectant management.

For respiratory viruses with available therapeutics, identifying an infection early during an illness can allow a patient to receive an antiviral treatment. Antivirals can help prevent complications and progression to severe disease, particularly for high-risk populations. Early initiation of oseltamivir within 48 hours to 5 days from the onset of illness has been associated with improved survival among patients with community-acquired pneumonia secondary to influenza.⁶

Another analysis suggests that treating even 10% of infected patients with Baloxavir, an antiviral for influenza, shortly after symptom onset would have prevented millions of infections and thousands of deaths in the United States during the severe 2017–18 influenza season.⁷ They are similar studies that associate Paxlovid use with reduction in hospitalizations and mortality in patients with COVID-19. In addition to its impact on hospitalization and progression to severe disease, a recent analysis in 2023 found that Paxlovid intervention also reduced the risk of the post-viral syndrome of long COVID-19 by 26% over a six-month period.⁸ By testing a patient with a respiratory panel, it can allow for earlier intervention with antivirals which in return reduce complications, decrease transmission, and provide targeted treatment to the patient.

Respiratory viruses can quickly progress to severe illness, particularly in individuals with chronic comorbidities, immunocompromised individuals, individuals who are pregnant, and the elderly population. Healthy individuals can protect these vulnerable populations from severe illness by testing for respiratory diseases. By knowing their viral respiratory status when symptomatic, patients can avoid these high-risk populations to prevent further spread of their illness. Additionally, utilizing testing before attending a large gathering, where there may be high risk individuals present, can help protect these individuals from obtaining a respiratory illness.

Testing for viral respiratory illnesses, even in healthy individuals or individuals with mild symptoms, can help: