Guidelines and Recommendations
This updated guidance continues to emphasize the importance of a comprehensive influenza prevention strategy that can be applied across the entire spectrum of healthcare settings. CDC will continue to evaluate new information as it becomes available and will update or expand this guidance as needed. Additional information on influenza immunization, prevention, treatment, and control can be found on Seasonal Influenza (Flu) web site.
Definition of Healthcare Settings
For the purposes of this guidance, healthcare settings include, but are not limited to, acute-care hospitals; long-term care facilities, such as nursing homes and skilled nursing facilities; physicians’ offices; urgent-care centers, outpatient clinics; and home healthcare. This guidance is not intended to apply to other settings whose primary purpose is not healthcare, such as schools or worksites, because many of the aspects of the populations and feasible countermeasures will differ substantially across settings. However, elements of this guidance may be applicable to specific sites within non-healthcare settings where care is routinely delivered (e.g. a medical clinic embedded within a workplace or school).
Definition of Healthcare Personnel
HCP refers to all persons, paid and unpaid, working in healthcare settings who have the potential for exposure to patients and/or to infectious materials, including body substances, contaminated medical supplies and equipment, contaminated environmental surfaces, or contaminated air. HCP include, but are not limited to, physicians, nurses, nursing assistants, therapists, technicians, emergency medical service personnel, dental personnel, pharmacists, laboratory personnel, autopsy personnel, students and trainees, contractual personnel, home healthcare personnel, and persons not directly involved in patient care (e.g., clerical, dietary, house-keeping, laundry, security, maintenance, billing, chaplains, and volunteers) but potentially exposed to infectious agents that can be transmitted to and from HCP and patients. This guidance is not intended to apply to persons outside of healthcare settings for reasons discussed in the previous section.
Influenza is primarily a community-based infection that is transmitted in households and community settings. Each year, 5% to 20% of U.S. residents acquire an influenza virus infection, and many will seek medical care in ambulatory healthcare settings (e.g., pediatricians’ offices, urgent-care clinics). In addition, more than 200,000 persons, on average, are hospitalized each year for influenza-related complications. Healthcare-associated influenza infections can occur in any healthcare setting and are most common when influenza is also circulating in the community. Therefore, the influenza prevention measures outlined in this guidance should be implemented in all healthcare settings. Supplemental measures may need to be implemented during influenza season if outbreaks of healthcare-associated influenza occur within certain facilities, such as long-term care facilities and hospitals [refs: Infection Control Measures for Preventing and Controlling Influenza Transmission in Long-Term Care Facilities].
Influenza Modes of Transmission
Traditionally, influenza viruses have been thought to spread from person to person primarily through large-particle respiratory droplet transmission (e.g., when an infected person coughs or sneezes near a susceptible person). Transmission via large-particle droplets requires close contact between source and recipient persons, because droplets generally travel only short distances (approximately 6 feet or less) through the air. Indirect contact transmission via hand transfer of influenza virus from virus-contaminated surfaces or objects to mucosal surfaces of the face (e.g., nose, mouth) may also occur. Airborne transmission via small particle aerosols in the vicinity of the infectious individual may also occur; however, the relative contribution of the different modes of influenza transmission is unclear. Airborne transmission over longer distances, such as from one patient room to another has not been documented and is thought not to occur. All respiratory secretions and bodily fluids, including diarrheal stools, of patients with influenza are considered to be potentially infectious; however, the risk may vary by strain. Detection of influenza virus in blood or stool in influenza infected patients is very uncommon.
Fundamental Elements to Prevent Influenza Transmission
Preventing transmission of influenza virus and other infectious agents within healthcare settings requires a multi-faceted approach. Spread of influenza virus can occur among patients, HCP, and visitors; in addition, HCP may acquire influenza from persons in their household or community. The core prevention strategies include:
Successful implementation of many, if not all, of these strategies is dependent on the presence of clear administrative policies and organizational leadership that promote and facilitate adherence to these recommendations among the various people within the healthcare setting, including patients, visitors, and HCP. These administrative measures are included within each recommendation where appropriate. Furthermore, this guidance should be implemented in the context of a comprehensive infection prevention program to prevent transmission of all infectious agents among patients and HCP.
1. Promote and administer seasonal influenza vaccine
Annual vaccination is the most important measure to prevent seasonal influenza infection. Achieving high influenza vaccination rates of HCP and patients is a critical step in preventing healthcare transmission of influenza from HCP to patients and from patients to HCP. According to current national guidelines, unless contraindicated, vaccinate all people aged 6 months and older, including HCP, patients and residents of long-term care facilities [refs: Prevention and Control of Influenza with Vaccines and Seasonal Influenza Vaccination Resources for Health Professionals].
Systematic strategies employed by some institutions to improve HCP vaccination rates have included providing incentives, providing vaccine at no cost to HCP, improving access (e.g., offering vaccination at work and during work hours), requiring personnel to sign declination forms to acknowledge that they have been educated about the benefits and risks of vaccination, and mandating influenza vaccination for all HCP without contraindication. Many of these approaches have been shown to increase vaccination rates; tracking influenza vaccination coverage among HCP can be an important component of a systematic approach to protecting patients and HCP. Regardless of the strategy used, strong organizational leadership and an infrastructure for clear and timely communication and education, and for program implementation, have been common elements in successful programs. More information on different HCP vaccination strategies can be found in the Appendix: Influenza Vaccination Strategies.
2. Take Steps to Minimize Potential Exposures
A range of administrative policies and practices can be used to minimize influenza exposures before arrival, upon arrival, and throughout the duration of the visit to the healthcare setting. Measures include screening and triage of symptomatic patients and implementation of respiratory hygiene and cough etiquette. Respiratory hygiene and cough etiquette are measures designed to minimize potential exposures of all respiratory pathogens, including influenza virus, in healthcare settings and should be adhered to by everyone – patients, visitors, and HCP – upon entry and continued for the entire duration of stay in healthcare settings.
Before Arrival to a Healthcare Setting
Upon Entry and During Visit to a Healthcare Setting
3. Monitor and Manage Ill Healthcare Personnel
HCP who develop fever and respiratory symptoms should be:
HCP who develop acute respiratory symptoms without fever may still have influenza infection and should be:
Facilities and organizations providing healthcare services should:
4. Adhere to Standard Precautions
During the care of any patient, all HCP in every healthcare setting should adhere to standard precautions, which are the foundation for preventing transmission of infectious agents in all healthcare settings. Standard precautions assume that every person is potentially infected or colonized with a pathogen that could be transmitted in the healthcare setting. Elements of standard precautions that apply to patients with respiratory infections, including those caused by the influenza virus, are summarized below. All aspects of standard precautions (e.g., injection safety) are not emphasized in this document but can be found in the CDC Healthcare Infection Control Practices Advisory Committee (HICPAC) guideline titled Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings, Guidelines for Preventing Healthcare-Associated Pneumonia and Guidelines for Hand Hygiene in Healthcare Settings Published 2002 pdf iconpdf icon[495 KB, 56 pages].
5. Adhere to Droplet Precautions
6. Use Caution when Performing Aerosol-Generating Procedures
Some procedures performed on patients with suspected or confirmed influenza infection may be more likely to generate higher concentrations of infectious respiratory aerosols than coughing, sneezing, talking, or breathing. These procedures potentially put HCP at an increased risk for influenza exposure. Although there are limited data available on influenza transmission related to such aerosols, many authorities [refs: WHOexternal iconexternal icon, recommend that additional precautions be used when such procedures are performed. These include some procedures that are usually planned ahead of time, such as bronchoscopy, sputum induction, elective intubation and extubation, and autopsies; and some procedures that often occur in unplanned, emergent settings and can be life-saving, such as cardiopulmonary resuscitation, emergent intubation and open suctioning of airways. Ideally, a combination of measures should be used to reduce exposures from these aerosol-generating procedures when performed on patients with suspected or confirmed influenza. However, it is appropriate to take feasibility into account, especially in challenging emergent situations, where timeliness in performing a procedure can be critical to achieving a good patient outcome. Precautions for aerosol-generating procedures include:
7. Manage Visitor Access and Movement Within the Facility
Limit visitors for patients in isolation for influenza to persons who are necessary for the patient’s emotional well-being and care. Visitors who have been in contact with the patient before and during hospitalization are a possible source of influenza for other patients, visitors, and staff.
For persons with acute respiratory symptoms, facilities should develop visitor restriction policies that consider location of patient being visited (e.g., oncology units) and circumstances, such as end-of-life situations, where exemptions to the restriction may be considered at the discretion of the facility. Regardless of restriction policy, all visitors should follow precautions listed in the respiratory hygiene and cough etiquette section.
Visits to patients in isolation for influenza should be scheduled and controlled to allow for:
8. Monitor Influenza Activity
Healthcare settings should establish mechanisms and policies by which HCP are promptly alerted about increased influenza activity in the community or if an outbreak occurs within the facility and when collection of clinical specimens for viral culture may help to inform public health efforts. Close communication and collaboration with local and state health authorities is recommended. Policies should include designations of specific persons within the healthcare facility who are responsible for communication with public health officials and dissemination of information to HCP.
9. Implement Environmental Infection Control
Detailed information on environmental cleaning in healthcare settings can be found in CDC’s Guidelines for Environmental Infection Control in Health-Care Facilities and Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings [section IV.F. Care of the environment.
Standard cleaning and disinfection procedures (e.g., using cleaners and water to preclean surfaces prior to applying disinfectants to frequently touched surfaces or objects for indicated contact times) are adequate for influenza virus environmental control in all settings within the healthcare facility, including those patient-care areas in which aerosol-generating procedures are performed. Management of laundry, food service utensils, and medical waste should also be performed in accordance with standard procedures. There are no data suggesting these items are associated with influenza virus transmission when these items are properly managed. Laundry and food service utensils should first be cleaned, then sanitized as appropriate. Some medical waste may be designated as regulated or biohazardous waste and require special handling and disposal methods approved by the State authorities.
10. Implement Engineering Controls
Consider designing and installing engineering controls to reduce or eliminate exposures by shielding HCP and other patients from infected individuals. Examples of engineering controls include installing physical barriers such as partitions in triage areas or curtains that are drawn between patients in shared areas. Engineering controls may also be important to reduce exposures related to specific procedures such as using closed suctioning systems for airways suction in intubated patients. Another important engineering control is ensuring that appropriate air-handling systems are installed and maintained in healthcare facilities.
11. Train and Educate Healthcare Personnel
Healthcare administrators should ensure that all HCP receive job- or task-specific education and training on preventing transmission of infectious agents, including influenza, associated with healthcare during orientation to the healthcare setting. This information should be updated periodically during ongoing education and training programs. Competency should be documented initially and repeatedly, as appropriate, for the specific staff positions. A system should be in place to ensure that HCP employed by outside employers meet these education and training requirements through programs offered by the outside employer or by participation in the healthcare facility’s program.
12. Administer Antiviral Treatment and Chemoprophylaxis of Patients and Healthcare Personnel when Appropriate
Refer to the CDC web site for the most current recommendations on the use of antiviral agents for treatment and chemoprophylaxis. Both HCP and patients should be reminded that persons treated with influenza antiviral medications continue to shed influenza virus while on treatment. Thus, hand hygiene, respiratory hygiene and cough etiquette practices should continue while on treatment.
13. Considerations for Healthcare Personnel at Higher Risk for Complications of Influenza
HCP at higher risk for complications from influenza infection include pregnant women and women up to 2 weeks postpartum, persons 65 years old and older, and persons with chronic diseases such as asthma, heart disease, diabetes, diseases that suppress the immune system, certain other chronic medical conditions, and morbid obesity. Vaccination and early treatment with antiviral medications are very important for HCP at higher risk for influenza complications because they can decrease the risk of hospitalizations and deaths. HCP at higher risk for complications should check with their healthcare provider if they become ill so that they can receive early treatment.
Some HCP may identify themselves as being at higher risk of complications, and express concerns about their risks. These concerns should be discussed and the importance of careful adherence to these guidelines should be emphasized. Work accommodations to avoid potentially high-risk exposure scenarios, such as performing or assisting with aerosol-generating procedures on patients with suspected or confirmed influenza, may be considered in some settings, particularly for HCP with more severe or unstable underlying disease.1
Appendix: Additional Information about Influenza
Information about Facemasks:
Information about Respirators:
Key Facts about Influenza
Clinical Information (signs and symptoms, modes of transmission, viral shedding)
World Health Organization (WHO). Epidemic- and pandemic-prone acute respiratory diseases – Infection prevention and control in health careexternal icon
Infection Control Measures for Preventing and Controlling Influenza Transmission in Long-Term Care Facilities
Preventing Opportunistic Infections in HSCT/Bone Marrow Transplant Recipients (p. 18)
Seasonal Influenza Vaccination Resources for Health Professionals
Guidance for Prevention and Control of Influenza in the Peri- and Postpartum Settings
Clinical Description & Lab Diagnosis of Influenza
Treatment (Antiviral Drugs)
Influenza Vaccination Strategies
Veterans Health Administration Influenza Manualpdf iconexternal icon
¹In considering this guidance, employers should familiarize themselves with the Americans with Disabilities Act of 1990 (Pub. L. 101-336) (ADA), which may impact how they implement this guidance. Details specific to the ADAexternal icon and influenza preparednessexternal icon are provided on the U.S. Equal Employment Opportunity Commission web site.