- According to CDC guidance, testing is not needed for all patients with signs and symptoms of influenza to make antiviral treatment decisions.
- Once influenza activity has been documented in the community or geographic area, a clinical diagnosis of influenza can be made for outpatients with signs and symptoms consistent with suspected influenza, especially during periods of peak influenza activity in the community.
- Information for Clinicians on Influenza Virus Testing
- Guidance on the use of RIDTs
Information on this page pertains to healthcare settings including acute care hospitals, long-term care facilities (such as nursing homes and skilled nursing facilities), physicians’ offices, urgent care centers, and outpatient clinics. The recommendations and guidance may also be applicable to other settings where healthcare is delivered, such as school/work health clinics and home healthcare. Although assisted living facilities may not traditionally be thought of as healthcare facilities, the medical needs of the individuals who reside there sometimes necessitate special infection prevention precautions, so recommendations and resources for this setting are included in the long-term care section of this page. Guidance and recommendations for other settings such as daycare centers, businesses, and schools can be found here.
General Information for Healthcare Professionals:
- Influenza Infection Control in Health Care Facilities (CDC) – summary documents, guidelines, and educational resources
- Seasonal Influenza Information for Healthcare Professionals (CDC)
- Respiratory Hygiene and Cough Etiquette in Healthcare Settings (CDC)
To Prevent the Spread of Flu in Healthcare Facilities
Follow the CDC guidelines and recommendations for the prevention of seasonal influenza in healthcare settings. More information on infection control in Healthcare Facilities can be found here.
Healthcare workers should:
- Implement droplet precautions for patients with influenza.
- Promote good respiratory hygiene practices.
- Instruct patients, visitors, and other healthcare workers to use a tissue to cover their nose and mouth when coughing or sneezing.
- Provide adequate supplies (tissues, face masks, trash cans, alcohol-based hand sanitizer).
- Encourage people in common areas who have respiratory symptoms to sit as far away from others as possible or wear a surgical mask, if they are able to tolerate it.
- Triage incoming patients and have a separate waiting area for patients with respiratory symptoms equipped with the necessary supplies (tissues, face masks, trash cans, alcohol-based hand sanitizer).
- Administer antiviral treatment and chemoprophylaxis to patients and healthcare personnel when appropriate.
- If sick with flu-like illness, stay home for at least 24 hours after fever has gone away (without the use of a fever-reducing medicine) and limit contact with other people.
- Facility administrators should:
- Encourage and administer seasonal influenza vaccine. Implement strategies to improve healthcare personnel influenza vaccination rates.
- Provide adequate tissues, face masks, and hand hygiene supplies for staff and in patient waiting areas and rooms.
- Monitor and manage ill healthcare workers.
- Antiviral treatment with oseltamivir is recommended as early as possible for any patient with confirmed or suspected influenza who: is hospitalized; has severe, complicated, or progressive illness; or is at higher risk for influenza complications.
- Do not wait for laboratory confirmation of influenza when deciding whether to begin antiviral treatment. Empiric antiviral treatment should be started as soon as possible in the above priority groups.
- Clinicians can consider early empiric antiviral treatment of non-high-risk outpatients with suspected influenza [e.g., influenza-like illness (fever with either cough or sore throat)] based upon clinical judgement, if treatment can be initiated within 48 hours of illness onset.
- For outpatients with complications or progressive disease and suspected or confirmed influenza (e.g., pneumonia, or exacerbation of underlying chronic medical conditions), initiation of antiviral treatment with oral oseltamivir is recommended as soon as possible.
- For outpatients with suspected or confirmed uncomplicated influenza, oral oseltamivir, inhaled zanamivir, intravenous peramivir, or oral baloxavir may be used for treatment, depending upon approved age groups and contraindications. In one randomized controlled trial, baloxavir had greater efficacy than oseltamivir in adolescents and adults with influenza B virus infection (Ison, 2020).
- Antiviral chemoprophylaxis should be used for prevention of influenza when indicated for institutional influenza outbreaks, and may be considered for those who have contraindications to influenza vaccination.
- For patients who do not respond to antiviral treatment, antiviral susceptibility laboratory testing should be considered.
- Antibiotics are not effective against influenza. See CDC’s website for more information on the appropriate use of antibiotics in the healthcare setting.
- CDC Health Advisory Regarding Increasing Seasonal Influenza A (H3N2) Activity, Especially Among Young Adults and in College and University Settings, During SARA-CoV-2 Co-Circulation (November 3, 2021)
- CDC Health Advisory Regarding Highly Pathogenic Avian Influenza A(H5N1) Virus: Recommendations for Human Health Investigations and Response (April 29, 2022)
- CDC Links to Current and Past Guidance from ACIP
Role of testing in making treatment decisions
- To make treatment decisions, diagnostic testing is not necessary for all patients with signs and symptoms of influenza. Once influenza activity has been documented in the community or geographic area, a clinical diagnosis of influenza can be made for outpatients with signs and symptoms consistent with suspected influenza, especially during periods of peak influenza activity in the community.
- If influenza is suspected clinically and antiviral treatment is indicated, treatment should not be delayed while waiting for the results of flu testing.
- Rapid influenza diagnostic tests (RIDTs) can be useful to identify influenza virus infection. These tests produce very quick results, but the results need to be interpreted with caution. Sensitivity of these tests generally ranges from 40-70%. False positive results are not as common (specificity ranges from 85-100%).
- A negative RIDT result does not exclude a diagnosis of influenza in a patient with suspected influenza.
- To minimize false rapid influenza diagnostic test results:
- Collect specimens as early in the illness as possible (ideally less than 4 days of illness onset)
- Follow manufacturer’s instructions, including acceptable specimens and handling
- Follow-up negative results with confirmatory tests (RT-PCR or viral culture) if a laboratory-confirmed influenza diagnosis is desired
- Strategies for Improving Rapid Influenza Testing in Ambulatory Settings – four free 30-minute online courses developed by The Joint Commission
- Other testing (immunofluorescence, RT-PCR, viral culture) is more accurate, but can take longer. Molecular tests are helpful in the identification of novel influenza viruses.
- Patients suspected of having novel influenza infection require specialized testing that must be coordinated through your local health department. Relevant illness and severity criteria as well as exposure history criteria (such as recent travel to areas where novel human influenza infections have occurred or recent contact with swine) must be met before public health testing occurs. To learn more about specific testing criteria and specimen collection procedures, consult the VDH Novel, Variant, and Pandemic Influenza page. Be sure to report any unusual influenza cases to your local health department.
- Periodically throughout the influenza season, positive flu specimens are forwarded by public health laboratories to CDC for testing for resistance to oseltamivir and zanamivir.
Additional testing information
- For more information on clinical description and laboratory diagnosis of influenza including a testing algorithm, click here.
- To view an instructional video that demonstrates how to collect a nasopharyngeal (NP) swab, click here.
Sentinel influenza surveillance testing
- Some clinicians participate in the sentinel surveillance program with VDH by collecting samples for confirmatory influenza testing at the state public health laboratory. These specimens help characterize the strains that are circulating in the community. If you would like to participate in sentinel surveillance, please contact your district epidemiologist or the VDH influenza surveillance coordinator at email@example.com.
- Vaccination recommendations and protocols
- Influenza vaccination of healthcare personnel
- To report an adverse event associated with influenza vaccination, click here (Vaccine Adverse Event Reporting System)
- Fact sheets
- CDC Fight the Flu Toolkit for Healthcare Providers
- CDC Be Antibiotics Aware Social Media Toolkit
- CDC Digital Media Toolkit: 2021-2022
Resources for Long-Term Care Facilities (Including Assisted Living Facilities)
- CDC Toolkit: Increasing Influenza Vaccination among Healthcare Personnel in Long-Term Care Settings
- Interim Guidance for Outbreak Management in Long-Term Care Facilities (CDC)
- Fact sheets
- Guidelines for the Prevention and Control of Influenza in Non-Healthcare Group Settings (October 2018) (VDH) – applicable to assisted living facilities
- Guidelines for the Prevention and Control of Influenza in Nursing Homes and Long-Term Care Facilities During the COVID-19 Pandemic (Dec 2020) (VDH)
Surveillance and Reporting
- For more information about current influenza activity levels and healthcare facility reporting requirements in Virginia, click here.
- National flu activity and surveillance (CDC)
- Healthcare personnel influenza vaccination reporting requirements for healthcare facilities