Counsel Patients About Symptoms for Different Respiratory Viruses

With respiratory virus season in full swing, pharmacists are likely receiving questions about different symptoms.

It can be difficult to differentiate between the respiratory viruses, as they share many common symptoms (see Table^1-6). There are tests to distinguish among COVID-19, influenza, and respiratory syncytial virus (RSV). If these tests come back negative, then patients could be experiencing symptoms from the common cold. Pharmacists can play an important role in educating patients about symptoms associated with the common cold, COVID-19, influenza, and RSV.

Respiratory Virus Symptoms
Although the common cold, COVID-19, influenza, and RSV share similar symptoms, there are some distinguishing characteristics that set some of these respiratory viruses apart. Cold symptoms are typically milder, and the onset is generally gradual.¹ The common cold does not usually cause a fever or serious health complications like COVID-19, influenza, and RSV do.² Adults will typically have at least 2 to 3 colds per year, and children are infected with even more colds annually.¹ Most individuals recover from the common cold within 7 to 10 days.¹

COVID-19 symptoms can range from mild to severe, and they can begin 2 to 14 days after exposure.³ With the Omicron variants, the average incubation period is on average 3 and a half days.⁴ One of the hallmark symptoms of COVID-19 that is not typically seen with other respiratory viruses is loss of smell and taste.³ Individuals infected with influenza typically develop symptoms 1 to 4 days after exposure.⁵ Additionally, symptoms for influenza are very similar to COVID-19. Both COVID-19 and flu can cause coughs, headaches, fever, muscle pain, and shortness of breath.⁵

Individuals with RSV can have mild cold-like symptoms, but they can also experience severe complications.⁶ Infants and older adults are at higher risk of experiencing severe symptoms.⁶ Wheezing is considered a hallmark symptom associated with RSV.⁶ Individuals infected with RSV can be contagious for 3 to 8 days, but they can continue to spread the virus for up to 4 weeks, in some cases.⁶   

Because symptoms are similar among colds, COVID-19, influenza, and RSV, testing is the best way to determine the virus. Although there is no test for the common cold, there are tests for the other 3 respiratory viruses. Individuals who test negative for the other viruses could be experiencing the common cold. The only virus that patients can self-test for at home, with the results provided immediately, is COVID-19.⁷ At-home OTC COVID-19 diagnostic tests are typically antigen rapid tests that provide results within 15 minutes.⁷ BinaxNow and Flowflex are examples of COVID-19 at-home tests.⁷ Patients can obtain rapid tests monthly free of charge at local pharmacies through most insurance plans and Medicare. Each household in the United States can also order 4 free at-home COVID-19 tests through the federal government.⁸ Labcorp developed the first polymerase chain reaction COVID-19, flu, and RSV home collection test kit.⁹ The kit must be shipped back to the laboratory with the nasal swab for an analysis.⁹ However, it can take 1 to 2 days after the lab receives the kit for patients to find out the results.⁹ 

Table. COVID-19, Common Cold, Influenza, and RSV Shared Symptoms^1-6

Congestion

Cough

Fatigue

Muscle aches

Rhinorrhea

Sore throat

References

1. Common colds: protect yourself and others. CDC. Updated November 29, 2021. Accessed December 26, 2022. https://www.cdc.gov/features/rhinoviruses/index.html#:~:text=Adults%20have%20an%20average%20of,sore%20throat

2. Cold versus flu. CDC. Updated September 29, 2022. Accessed December 25, 2022. https://www.cdc.gov/flu/symptoms/coldflu.htm

3. Symptoms of COVID-19. CDC. Updated October 26, 2022. Accessed December 25, 2022. https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html

4. Wu Y, Kang L, Guo Z, et al. Incubation period of COVID-19 caused by unique SARS-CoV-2 strains: a systematic review and meta-analysis. JAMA Netw Open. 2022;5(8):e2228008. doi:10.1001/jamanetworkopen.2022.28008

5. Similarities and differences between flu and COVID-19. CDC. Accessed December 25, 2022. https://www.cdc.gov/flu/symptoms/flu-vs-covid19.htm

6. Respiratory syncytial virus infection (RSV). CDC. Updated October 28, 2022. Accessed December 25, 2022. https://www.cdc.gov/rsv/index.html

7. At-home OTC COVID-19 diagnostic tests. FDA. February 7, 2023. Accessed February 8, 2023. https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/home-otc-covid-19-diagnostic-tests

8. Get free at-home COVID-19 tests this winter. COVID.gov. Accessed December 26, 2022. https://www.covid.gov/tests

9. COVID-19 + flu + RSV test home collection kit. Labcorp. Accessed December 26, 2022. https://www.ondemand.labcorp.com/at-home-test-kits/covid-19-flu-rsv-test-home-collection-kit