Interim Guidance for Influenza Outbreak Management in Long-Term Care and Post-Acute Care Facilities

Long-term care facilities

The following guidance is current for the 2023-2024 influenza season.

Long-term care facilities may be defined as institutions, such as nursing homes and skilled nursing facilities, that provide healthcare to people (including children) who are unable to manage independently in the community. This care may represent custodial or chronic care management or short-term rehabilitative services.

Influenza can be introduced into a long-term care facility by newly admitted residents, healthcare personnel, and visitors. Spread of influenza can occur between and among residents, healthcare personnel and visitors. Residents of long-term care facilities can experience severe and fatal illness during influenza outbreaks.

Preventing transmission of influenza viruses and other infectious agents within healthcare settings, including in long-term care facilities, requires a multi-faceted approach that includes the following:

1. Influenza Vaccination
2. Influenza Testing
3. Infection Prevention and Control Measures
4. Antiviral Treatment, and
5. Antiviral Chemoprophylaxis

Before an Outbreak Occurs

Influenza vaccination should be provided routinely to all residents and healthcare personnel of long-term care facilities.

Residents

If possible, all residents should receive inactivated influenza vaccine (IIV) annually before influenza season. For persons aged ≥65 years, the following trivalent influenza vaccines are recommended: high-dose IIV, adjuvanted IIV, or recombinant influenza vaccine. If not available, standard-dose IIV may be given. In the majority of seasons, influenza vaccines will become available to long-term care facilities beginning in September, and influenza vaccination should be offered by the end of October. Informed consent is required to implement a standing order for vaccination, but this does not necessarily mean a signed consent must be present. Although vaccination by the end of October is recommended, influenza vaccine administered in December or later, even if influenza activity has already begun, is likely to be beneficial in the majority of influenza seasons because the duration of the season is variable, and influenza activity might not occur in certain communities until February or March.

In the event that a new patient or resident is admitted after the influenza vaccination program has concluded in the facility, the benefits of vaccination should be discussed, educational materials should be provided, and an opportunity for vaccination should be offered to the new resident as soon as possible after admission to the facility. Since October 2005, the Centers for Medicare and Medicaid Services (CMS) has required nursing homes participating in Medicare and Medicaid programs to offer all residents influenza and pneumococcal vaccines and to document the results. According to the requirements, each resident is to be vaccinated unless contraindicated medically, the resident or legal representative refuses vaccination, or the vaccine is not available because of shortage. This information is to be reported as part of the CMS Minimum Data Set, which tracks nursing home health parameters.

Healthcare Personnel

CDC and the Advisory Committee on Immunization Practices (ACIP), recommend that all U.S. healthcare personnel get vaccinated annually against influenza.

• Healthcare personnel who get vaccinated may help to reduce:
  • transmission of influenza,
  • staff illness and absenteeism, and
  • influenza-related illness and death, especially among people at increased risk for severe influenza complications.

Surveillance

When there is influenza activity in the local community, active daily surveillance (defined below) for influenza illness should be conducted among all new and current residents, healthcare personnel, and visitors of long-term care facilities, and should be continued until the end of influenza season. Healthcare personnel, and visitors who are identified with any illness symptoms should be excluded from the facility until their illness has resolved. Older adults and other long-term care residents, including those who are medically fragile and those with neurological or neurocognitive conditions, may manifest atypical signs and symptoms of influenza virus infection (e.g., behavior change), and may not have fever. Ill residents should be placed on droplet precautions with room restriction and be excluded from participating in group activities as described below.

Influenza Testing

Even if it's not influenza season, influenza testing should occur when any resident has signs and symptoms of acute respiratory illness or influenza-like illness.

When there is a confirmed or suspected influenza outbreak (2 or more ill residents)

If one laboratory-confirmed influenza positive case is identified along with other cases of acute respiratory illness in a unit of a long-term care facility, an influenza outbreak might be occurring. Active surveillance for additional cases should be implemented as soon as possible once one case of laboratory-confirmed influenza is identified in a facility. When 2 cases of laboratory-confirmed influenza are identified within 72 hours of each other in residents on the same unit, outbreak control measures should be implemented as soon as possible.

Implementation of outbreak control measures can also be considered as soon as possible when one or more residents have acute respiratory illness with suspected influenza and the results of influenza molecular tests are not available the same day of specimen collection. While unusual, an influenza outbreak can occur outside of the normal influenza season; therefore, testing for influenza viruses and other respiratory pathogens should also be performed during non-influenza season periods.

Even if it’s not influenza season, influenza testing should occur when any resident has signs and symptoms that could be due to influenza,A and especially when two residents or more develop respiratory illness within 72 hours of each other.

• Determine if influenza virus is the causative agent by performing influenza testing on upper respiratory tract specimens (i.e., nasopharyngeal swab, nasal swabs, nasopharyngeal or nasal aspirates, or combined nasal and throat swabs) of ill residents with recent onset of signs and symptoms suggestive of influenza or acute respiratory illness.
• The following influenza tests are recommended: molecular assays, including rapid molecular assays, other molecular tests, or reverse transcription polymerase chain reaction (RT-PCR).
• If influenza molecular assays are not available and antigen detection tests are used such as rapid influenza diagnostic tests (RIDTs) or immunofluorescence assays, false negative results can occur because RIDTs and immunofluorescence assays have lower sensitivity than molecular assays for detection of influenza viruses. If influenza is suspected and RIDTs or immunofluorescence results are negative, perform confirmatory testing using molecular influenza assays. Information on influenza diagnostic testing is available online or by contacting your state public health laboratory.
• Influenza testing with molecular assays such as RT-PCR may be available at a local or state public health laboratory.
• Viral culture should be performed at a public health laboratory if additional information on influenza viruses, such as influenza A virus subtype, antigenic characterization to compare with influenza vaccine strains, or antiviral resistance data, are needed.
• Determining influenza virus type or subtype of influenza A virus can help inform antiviral therapy decisions.

Implement daily active surveillance for acute respiratory illness among all residents, healthcare personnel and visitors to the facility.

• During an outbreak, once a single laboratory-confirmed case of influenza has been identified in a resident, it is likely there are other cases among exposed persons.
• Conduct daily active surveillance until at least 1 week after the last laboratory-confirmed influenza case was identified.
• Test for influenza with a molecular assay in the following:
  • Ill persons who are in the affected unit(s) as well as previously unaffected units in the facility
  • Persons who develop acute respiratory illness symptoms after beginning antiviral chemoprophylaxisA
• Ensure that the laboratory performing influenza testing notifies the facility of tests results promptly.
• The local public health and state health departments should be notified of every suspected or confirmed influenza outbreak in a long-term care facility, especially if a resident develops influenza while on or after receiving antiviral chemoprophylaxis.

Implement Standard and Droplet Precautions for all residents with suspected or confirmed influenza.

CDC's guidance titled Prevention Strategies for Seasonal Influenza in Healthcare Settings contains details on the prevention strategies for all healthcare settings. Specific recommendations are highlighted below.

Standard Precautions are intended to be applied to the care of all patients in all healthcare settings, regardless of the suspected or confirmed presence of an infectious agent. Implementation of Standard Precautions constitutes the primary strategy for the prevention of healthcare-associated transmission of infectious agents among patients and healthcare personnel.

Examples of standard precautions include:

• Wearing gloves if hand contact with respiratory secretions or potentially contaminated surfaces is anticipated.
• Wearing a gown if soiling of clothes with a resident's respiratory secretions is anticipated.
• Changing gloves and gowns after each resident encounter and performing hand hygiene
• Perform hand hygiene before and after touching the resident, after touching the resident's environment, or after touching the resident's respiratory secretions, whether or not gloves are worn. Gloves do not replace the need for performing hand hygiene.

Droplet Precautions are intended to prevent transmission of pathogens spread through close respiratory or mucous membrane contact with respiratory secretions. Droplet Precautions should be implemented for residents with suspected or confirmed influenza for 7 days after illness onset or until 24 hours after the resolution of fever and respiratory symptoms, whichever is longer, while a resident is in a healthcare facility.

Examples of Droplet Precautions include:

• Placing ill residents in a private room. If a private room is not available, place (cohort) residents suspected of having influenza residents with one another;
• Wear a facemask (e.g., surgical or procedure mask) upon entering the resident's room. Remove the facemask when leaving the resident's room and dispose of the facemask in a waste container.
• If resident movement or transport is necessary, have the resident wear a facemask (e.g., surgical or procedure mask), if possible.
• Communicate information about patients with suspected, probable, or confirmed influenza to appropriate healthcare personnel before transferring them to other departments.

These Precautions are part of the overall infection control strategy to protect against influenza in healthcare settings and should be used along with other infection control measures, such as isolation or cohorting of ill residents, screening employees and visitors for illness, furloughing ill healthcare personnel, and discouraging ill visitors from entering the facility.

In some cases, facilities may choose to apply Standard Precautions and Droplet Precautions for longer periods based on clinical judgment, such as in the case of young children or severely immunocompromised residents, who may shed influenza virus for longer periods of time.

Because residents with influenza may continue to shed influenza viruses while on antiviral treatment, infection control measures to reduce transmission, including following Standard and Droplet Precautions, should continue while the resident is taking antiviral therapy. This will also reduce transmission of viruses that may have become resistant to antiviral drugs during therapy.

Administer influenza antiviral treatment and chemoprophylaxis to residents and healthcare personnel according to current recommendations.

All long-term care facility residents who have confirmed or suspected influenza should receive antiviral treatment immediately.

Initiation of antiviral treatment should not wait for laboratory confirmation of influenza.

Antiviral treatment works best when started within the first 2 days of symptoms. However, these medications can still help when given after 48 hours to those that are very sick, such as those who are hospitalized, or those who have progressive illness, or those who are at higher risk for complications of influenza.

Four influenza antiviral drugs approved by the U.S. Food and Drug Administration are recommended for treatment of uncomplicated influenza in the United States: neuraminidase inhibitors: oral oseltamivir (available as a generic version or under the trade name Tamiflu®), as a pill or suspension; zanamivir (trade name Relenza®), available as an inhaled powder using a disk inhaler device; and intravenous peramivir (trade name Rapivab®); and a cap-dependent endonuclease inhibitor: baloxavir marboxil (trade name Xofluza®) available as a tablet. It should be noted that some long-term care residents may have difficulty using the inhaler device for zanamivir.

Amantadine and rimantadine are NOT recommended for use because of high levels of antiviral resistance to these drugs among circulating influenza A viruses.

The recommended dosing and duration of antiviral treatment is twice daily for 5 days for neuraminidase inhibitors (oseltamivir and zanamivir), and one dose for intravenous peramivir. Oseltamivir is recommended for treatment of influenza in people of all ages. Baloxavir is approved for early treatment of uncomplicated influenza in people 5 years and older who are otherwise healthy or in people aged 12 years and older who are at higher risk for influenza complications and have been ill for no more than 2 days. A single oral dose of baloxavir is equivalent to 5 days of twice daily oral oseltamivir. Inhaled zanamivir is approved for early treatment of influenza in persons aged 7 years and older. Peramivir is approved for early treatment of influenza in persons aged 6 months and older. Dosage adjustment may be required for children and persons with certain underlying conditions. Clinicians should consult the manufacturers' package insert for approved ages, recommended drug dosing adjustments and contraindications.

In the setting of an influenza outbreak, empiric antiviral treatment should be given as soon as possible to residents with suspected influenza without waiting for influenza testing results, especially if results will not be available on the day of specimen collection. There are no data on use of baloxavir to control influenza outbreaks in long-term care facilities. Baloxavir is not recommended for pregnant women, severely immunosuppressed persons, those with severe disease, or hospitalized influenza patients. There are no data on baloxavir in these populations.

Having preapproved orders from physicians or plans to obtain orders for antiviral medications on short notice can substantially expedite administration of antiviral medications.

lf exposed, residents on units or wards with influenza cases in the long-term care facility (currently impacted wards) should receive antiviral chemoprophylaxis as soon as an influenza outbreak is determined.

When at least 2 patients are ill within 72 hours of each other and at least one resident has laboratory-confirmed influenza, the facility should promptly initiate antiviral chemoprophylaxis with oral oseltamivir to all non-ill residents living on the same unit as the resident with laboratory-confirmed influenza (outbreak affected units), regardless of whether they received influenza vaccination during the current season. Consideration may be given for extending antiviral chemoprophylaxis to residents on other unaffected units or wards in the long-term care facility based upon other factors (e.g., unavoidable mixing of residents or healthcare personnel from affected units and unaffected units).

Antiviral chemoprophylaxis is meant for residents who are not exhibiting influenza-like illness but who may be exposed or who may have been exposed to an ill person with influenza, to prevent transmission.

Use of antiviral drugs for chemoprophylaxis of influenza is a key component of influenza outbreak control in institutions that house residents at higher risk of influenza complications. While highly effective, antiviral chemoprophylaxis is not 100% effective in preventing influenza illness. Oseltamivir is the recommended antiviral drug for chemoprophylaxis of influenza in long-term care settings. Baloxavir is approved for post-exposure antiviral chemoprophylaxis of influenza in persons aged 5 years and older but no data are available from clinical trials of baloxavir chemoprophylaxis of influenza in long term care facility residents.

CDC recommends antiviral chemoprophylaxis with oseltamivir for a minimum of 2 weeks and continuing for at least 7 days after the last known laboratory-confirmed influenza case was identified on affected units.

Persons whose need for antiviral chemoprophylaxis is attributed to potential exposure to a person with laboratory-confirmed influenza should receive oral oseltamivir or inhaled zanamivir. Zanamivir should be used when persons require chemoprophylaxis as a result of exposure to influenza virus strains that are suspected or known to be oseltamivir-resistant.

Antiviral chemoprophylaxis can be considered or offered to unvaccinated personnel who provide care to persons at higher risk of influenza complications.

While CDC recommends judicious use of antiviral medications for chemoprophylaxis to reduce the possibility of development and spread of antiviral resistant influenza viruses, chemoprophylaxis may be considered for healthcare personnel, regardless of their influenza vaccination status, if the outbreak is caused by a strain of influenza virus that is not well matched by the vaccine, or based upon other factors (e.g., to reduce the risk of short staffing in facilities and units where clinical staff are limited and to reduce staff reluctance to provide care to residents with suspected or laboratory-confirmed influenza).

Antiviral chemoprophylaxis should also be considered in personnel for whom influenza vaccine is contraindicated.

An emphasis on close monitoring and early initiation of antiviral treatment is an alternative to chemoprophylaxis in managing certain persons who have had a suspected exposure to influenza virus. Healthcare personnel who have occupational exposures can be counseled about the early signs and symptoms of influenza and advised to contact their health-care provider immediately for evaluation and possible early initiation of antiviral treatment if clinical signs or symptoms develop.

For newly vaccinated healthcare personnel, antiviral chemoprophylaxis can be considered for up to 2 weeks following inactivated influenza vaccination until vaccine-induced immunity is acquired. Persons receiving antiviral chemoprophylaxis should not receive live attenuated influenza virus vaccine (LAIV), and persons receiving LAIV should not receive antiviral treatment or chemoprophylaxis until 14 days after LAIV administration.

Be Aware of the Possibility of an Antiviral Drug-Resistant Virus

Residents receiving antiviral medications who do not respond to treatment or who become sick with influenza after starting chemoprophylaxis might have an infection with an antiviral-resistant influenza virus. Persons receiving chemoprophylaxis who become sick should be switched to treatment dosing. If infection with an antiviral-resistant influenza virus is suspected, the local or state public health department should be notified promptly.

To limit the potential transmission of antiviral drug-resistant influenza virus, whether in chronic or acute-care settings or other closed settings, measures should be taken to reduce contact between ill persons taking antiviral drugs for treatment and other persons, including those receiving antiviral chemoprophylaxis.

Infection prevention and-control mea­sures are especially important for patients who are immunocompromised to reduce the risk for transmission of oseltamivir-resistant viruses.

Notify the health department if a resident develops influenza while on or after receiving antiviral chemoprophylaxis.

Consider the following additional measures to reduce transmission among residents and healthcare personnel:

• Have symptomatic residents stay in their own rooms as much as possible, including restricting them from common activities, and have their meals served in their rooms when possible.
• Limit the number of large group activities in the facility and consider serving all meals in resident rooms if possible when the outbreak is widespread (involving multiple units of the facility).
• Avoid new admissions or transfers to wards with symptomatic residentsB.
• Limit visitation and exclude ill persons from visiting the facility via posted notices. Consider restricting visitation by children during community outbreaks of influenza.
• Monitor healthcare personnel absenteeism due to respiratory symptoms and exclude those with influenza-like symptoms from work until at least 24 hours after they no longer have a fever.
• Restrict healthcare personnel movement from areas of the facility having illness to areas not affected by the outbreak.
• Administer the current season's influenza vaccine to unvaccinated residents and healthcare personnel as per current vaccination recommendations.
• The latest information on influenza vaccination, CDC's seasonal influenza vaccination resources for health professionals page, is available.

Resources

Influenza Vaccines

Antiviral Drugs

Influenza Testing

Infection Prevention and Control Measures

Reported Outbreaks in Long-Term Care Facilities

Additional References on Prevention and Control of Institutional Influenza Outbreaks