Flu, RSV, or COVID-19? Convergence of Three Viruses Creates Risk of Diagnostic Errors

Healthcare practitioners may see patients with influenza (flu), respiratory syncytial virus (RSV), and COVID-19 throughout the year, although respiratory viruses commonly occur during fall and winter. Seasonal peaks of flu, RSV, or COVID-19 infections may flood primary care offices and hospital emergency departments with patients while creating severe shortages of pediatric or adult hospital beds.

To promote patient safety, office practices should prepare to vaccinate and test for flu, RSV, and COVID-19. For the upcoming 2024–2025 season, vaccines are available for all three viruses:

• Flu vaccines are formulated to a trivalent vaccine, providing protection against the H1N1, H3N2, and a B/Victoria lineage virus.
• RSV vaccines are FDA approved for adults ages 60 and over, pregnant women during weeks 32 through 36 gestational age (providing protection for infants from birth through six months), and infants who meet certain criteria.
• COVID-19 vaccine updates were FDA approved in late August 2024, to cover the KP.2 and KP.3 variants. (Learn more about the latest COVID-19 variants.)

Diagnosis

For patients manifesting illness, the challenge in diagnosis is that all three viruses have similar symptoms, and testing must be performed for each to effectively confirm a correct diagnosis. Understanding the differences between the flu, RSV, and COVID-19 will help prevent misdiagnosis or delayed diagnosis when patients present with respiratory symptoms.

The American Academy of Pediatrics and the National Foundation for Infectious Diseases offer information on differential diagnosis between the three viruses. The CDC provides specific guidance on distinguishing the flu and COVID-19. General information for practitioners about each virus is available from the CDC as follows: flu, RSV, and COVID-19. The CDC addresses signs and symptoms, incubation periods, how the viruses spread, individuals at higher risk for severe illness, potential complications, and approved treatments.

Prevention

During flu season, it is possible that all three of the viruses may spread at the same time, and patients could become infected with one or all three of the diseases. To offset this possibility, it is important to offer appropriate screening, testing, and vaccinations. Refer to the CDC’s guidance on “Information for the 2024-2025 Flu Season.” Note that according to the CDC, flu, RSV, and COVID vaccines may be given on the same day if patients are eligible and vaccines follow the appropriate administration schedule. Some infectious disease experts recommend, however, that the RSV vaccine be given separately.

Patient Safety Strategies

Enhance patient safety by taking the following actions:

Patient Care

• Follow testing guidelines. Testing is the best method for determining which virus the patient may have while guiding your decisions about the appropriate treatment.
• Review the CDC’s “Information for Clinicians on Influenza Virus Testing” for patients with acute respiratory illness symptoms.
• Educate staff and patients on the vaccines for RSV: See ABRYSVO information for older adults and pregnant women, Beyfortus information for infants, and the CDC’s “RSV Vaccine Information Statements.” In 2024, the CDC provided updates for the RSV vaccine for older adults. Encourage your patients to get appropriate age-related vaccines.
• Ensure that the patient’s health record includes standard documentation about the possibility of contracting the flu, RSV, and/or COVID-19—including vaccination informed consent and informed refusal discussions. Find a sample informed refusal form on our Informed Consent Sample Forms page.
• Adopt a shared decision-making approach for patients at high risk for flu, RSV, or COVID-19 who are reluctant to get vaccines. Ensure that patients understand the risks of not being vaccinated. Learn more about shared decision making with the Agency for Healthcare Research and Quality’s “The SHARE Approach.” The shared decision-making/consent discussion should be well documented in the patient’s record. For additional information, see The Doctors Company article “Reduce Patient Safety Risks With Vaccinations, Including COVID-19.”
• Prescribe antivirals as necessary to prevent complications. See the CDC’s “Treating Flu with Antiviral Drugs” and “Types of COVID-19 Treatment,” and “Medscape: Respiratory Syncytial Virus Infection Medication.”

Office Measures

• Encourage all staff members to get vaccinated for the flu, RSV, and COVID-19 according to current guidelines. Offering vaccines at no cost to employees increases vaccination rates.
• Establish infection control protocols, and follow the CDC’s “Infection Control Guidance: SARS-CoV-2” and “Guide to Infection Prevention in the Outpatient Setting.”
• Appoint someone in the office to maintain all policies and procedures related to flu, RSV, and COVID-19 in a central location.
• Maintain, date, and document all changes in office policies related to personal protective equipment or other infection control policies. Provide and document related staff education.
• Ensure that all vaccinations available in the office are current and stored per manufacturer instructions.
• Provide consent forms and vaccination information statements for each vaccine.
• Depending on the community infection rates and patient population, consider the implementation of masking for patients, visitors, and staff.

Patient Education

• Display infographics and print resources in your office for the flu, RSV (OB), RSV Social Media Graphics, and COVID-19. Many free resources are available on the web.
• Offer videos in your waiting area to educate patients about infection control and getting vaccinated. Many options are available on YouTube.
• Educate patients to stop the spread of germs:
• Wash hands frequently.
• Maintain respiratory etiquette (including masking when necessary).
• Avoid touching eyes, nose, and mouth.
• Avoid close contact, particularly with those who are sick.
• Disinfect frequently touched surfaces and objects.
• Encourage self-isolation if sick.

Community Monitoring

• Adhere to local government or public health department recommendations for additional precautions. Check transmission levels in your community: “Weekly U.S. Influenza Surveillance Report,” “Surveillance of RSV,” and “COVID Data Tracker.”

For additional assistance, contact the Department of Patient Safety and Risk Management at (800) 421-2368 or by email.