Influenza Information for Healthcare Professionals and Facilities

2023-2024 Influenza Sentinel Surveillance Program 

VDH is recruiting providers to participate in the influenza sentinel surveillance programfor the 2023-2024 flu season. If you are interested in being a sentinel surveillance provider, please reach out at 

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 resources for this setting are included in the long-term care section of this page.

Guidance and recommendations for other settings such as child care centers, businesses, and schools can be found on the VDH Flu Information for Community Settings webpage.

Flu Prevention in Healthcare Facilities 

Follow the CDC guidelines and recommendations for the prevention of seasonal influenza in healthcare settings, including:  

  • Encourage and administer seasonal influenza vaccine. Implement strategies to improve healthcare personnel influenza vaccination rates. 
  • Promote good respiratory hygiene practices to  patients, visitors, and  healthcare workers. 
  • Provide adequate supplies (tissues, face masks, trash cans, alcohol-based hand sanitizer) to staff and in patient waiting areas and rooms. 
  • Encourage people in common areas who have respiratory symptoms to sit as far away from others as possible or wear a surgical mask, when possible. 
  • Triage incoming patients and if possible, have a separate waiting area for patients with respiratory symptoms equipped with the necessary supplies (tissues, face masks, trash cans, alcohol-based hand sanitizer). 
  • Implement droplet precautions with patients with confirmed or suspected flu. 
  • Administer antiviral treatment and chemoprophylaxis to patients and healthcare personnel when appropriate.
  • Healthcare workers and other staff with flu-like illness should 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. 
  • More information on infection control in healthcare settings can be found on the CDC webpage. 


When vaccine supply is limited, vaccination efforts should focus on delivering vaccination to the following people:  

  • Children aged 6 months through 4 years (59 months) 
  • People aged 50 years or older 
  • People with chronic medical conditions 
  • People who are immunosuppressed 
  • People who are or will be pregnant during the influenza season and people up to two weeks after delivery 
  • People who are aged 6 months through 18 years who are receiving aspirin or salicylate-containing medications and who might be at risk for experiencing Reye syndrome after influenza virus infection 
  • People who are residents of nursing homes and other long-term care facilities; 
  • American Indian or Alaska Native persons; 
  • People with extreme obesity (body-mass index [BMI] is 40 or greater); 
  • Health care personnel; 
  • Household contacts and caregivers of children under 5 years and adults aged 50 years and older; and 
  • Household contacts and caregivers of people with medical conditions that put them at increased risk for severe illness from influenza. 


Role of testing in making treatment decisions 

  • Diagnostic testing is not necessary for all patients with signs and symptoms of influenza to make 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 consistent signs and symptoms , 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 awaiting flu testing results. 
  • Unsubtypeable influenza results should be sent to DCLS. 
  • For more information see CDC Guide for considering influenza testing when influenza viruses are circulating in the community 

 Rapid influenza diagnostic tests 

  • Rapid influenza diagnostic tests (RIDTs) can be useful to identify influenza virus infection. These tests produce very quick results in less than 15 minutes, but results need to be interpreted with caution. Sensitivity of these tests generally ranges from 50-70%, which means false negatives are common False positive results are not as common (specificity ranges from  90-95%%). 
  • 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: 
    • Use RIDTs with high sensitivity and specificity. 
    • 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. 
  • For more information see CDC Information for Clinicians on Rapid Diagnostic Testing for Influenza. 

 Other types of testing 

Antiviral resistance 

  • 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 

Sentinel influenza surveillance testing 

Some clinicians participate in VDH’s sentinel surveillance program 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 


  •  Antiviral treatment 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 increased risk for influenza complications.
    • Oral oseltamivir is the recommended antiviral for hospitalized patients or those with severe, complicated, or progressive illness. 
  • 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  groups listed above, ideally within 48 hours of symptom onset. 
  • Providers can consider early empiric antiviral treatment of non-high-risk outpatients with suspected influenza [e.g., fever with either cough or sore throat) based upon clinical judgement, if treatment can be initiated within 48 hours of illness onset. 
  • Outpatients with complications or progressive disease and suspected or confirmed influenza (e.g., pneumonia, or exacerbation of underlying chronic medical conditions), should start  antiviral treatment with oral oseltamivir as soon as possible. 
  • Outpatients with suspected or confirmed uncomplicated influenza, may be treated with oral oseltamivir, inhaled zanamivir, intravenous peramivir, or oral baloxavir, 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. 
  • Patients who do not respond to antiviral treatment, should be considered for antiviral susceptibility laboratory testing. 
  • Antibiotics are not effective against influenza. See CDC’s website for more information on the appropriate use of antibiotics in the healthcare setting. 
  • CDC Treatment Resources: 

Surveillance and Reporting