Guidance for the Management of Pandemic (H1N1) 2009 Outbreaks in Closed Facilities

Revised: March 23, 2010

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This guidance is based on current, available scientific evidence and expert opinion about this emerging virus and is subject to review and change as new information becomes available. It should be read in conjunction with relevant provincial and territorial guidance documents. The Public Health Agency of Canada will be posting regular updates and related documents at www.phac-aspc.gc.ca.

Introduction

This guidance document has been prepared by the Public Health Agency of Canada (PHAC) to assist clinicians and public health professionals in managing pandemic (H1N1) 2009 (pH1N1) outbreaks in closed facilities in which high risk persons reside.  These guidelines are based on the management of seasonal influenza outbreaks and the evolving understanding of the immuno-epidemiology of pH1N1.This information provides recommendations for early detection measures, defines the triggers for investigating outbreaks, and describes antiviral treatment and prophylaxis strategies.

These recommendations do not supersede clinical and public health judgment or provide guidance on the management of individual patient care.  

Background

The goal of outbreak control is to limit the size of the outbreak within closed facilities thereby reducing the morbidity and mortality of residents and minimizing staff illness and absenteeism.

Definition of a closed facility

Based on the recently revised Annex on antiviral use during a pandemic^[1], a facility is deemed “closed” when it has a fixed residential population with limited turnover or has units or wards that can be closed.

Appropriate facilities for outbreak control include those with residents or patients that would be at high-risk for developing influenza-related complications, a surveillance capacity to detect influenza activity and the health care capacity to manage an antiviral regimen.

Potential settings meeting the above criteria are likely to include: long term care facilities; closed units in acute care hospitals; correctional facilities; specialty hospitals; rehabilitation centres; psychiatric facilities; retirement homes, and homes for special care. It should be noted that these facilities may have adult or pediatric residents.

Clinical Features of Influenza-like-Illness

The clinical symptoms of Influenza-like illness (ILI) usually include: sudden onset of cough and fever and commonly: sore throat, coryza, fatigue/malaise/prostration, myalgias/arthralgias, headache, decreased appetite and gastrointestinal symptoms (one or more of nausea, diarrhea and vomiting). Atypical presentations are most common in infants, the elderly and the immunocompromised. Individuals with chronic lung conditions may present with a new or worsening cough and pregnant women may report shortness of breath.

Early Detection

Surveillance

Surveillance is recommended on a year-round basis and includes surveillance of respiratory infections in both residents and staff. This is generally the responsibility of Infection Control and Occupational Health departments. It is useful to educate all staff in the detection of ILI and how to report this information to the Infection Control Practitioner (ICP) or designate.

Methods of data collection for patient ILI include passive surveillance by staff and active surveillance (i.e. chart review) by the ICP, designate or the physician. It is recommended that staff report their own respiratory illness to their supervisor or Occupational Health staff.  

Although the clinical symptoms of ILI usually include sudden onset of cough and fever, the recommended criteria for health care settings are more stringent: acute onset of respiratory illness with cough and/or fever and 1 or more of; sore throat, headache, arthralgia, myalgia or prostration. This is to minimize the risk of a Health Care Worker or other staff member introducing influenza into the healthcare setting.

Triggers for outbreak investigation

Triggers for outbreak investigation include:

• one confirmed case of pH1N1 within the facility, i.e. unit or floor or
• 2 or more cases of ILI, one of which can be a staff member with known contact with resident/patient case, in one geographic area within a 7 day period or
• more than one geographic area of the facility having a case of ILI

Laboratory testing

Confirmation of an outbreak requires laboratory testing. Specimens are best collected as soon as possible after symptom onset.  The preferred method of specimen collection in adults is a nasopharyngeal swab.  The specimen and requisition should be clearly labeled with exposure history and clinical symptoms.  Currently, the most sensitive and specific test is an RT-PCR. Due to the poor sensitivity of Point of Care (POC) testing, a negative test result does not rule out influenza and the potential for false positive test results also exists. Hence, POC tests are not recommended to inform clinical decisions about diagnosis and treatment in individual patients. However, POC testing may be the only option and may have a role in determining the presence and relative amount of influenza in remote and isolated communities. It remains important to confirm POC positive cases with RT-PCR.

Outbreak Control Measures

Infection Prevention and Control Measures

Best practices can be found in the: Guidance for Infection Prevention and Control Measures for Health Care Workers in Long-Term Care Facilities.^[2] Immunization is the primary prevention strategy for influenza.  The National Advisory Committee on Immunization (NACI) recommends seasonal flu immunization of those persons at high risk of influenza-related complications, and those capable of transmitting influenza to individuals at high risk of complications.^[3]pH1N1 2009 vaccine is now available for these individuals.

An outbreak is typically declared by the local Medical Officer of Health (MOH) or designate. Unless protocols are in place that note otherwise, the MOH will determine the extent of outbreak control measures and the need for restrictions on admissions and transfers from the facility.  Signage is generally posted at the entrance to an affected facility instructing those with ILI not to enter the premises.  It is recommended that all staff, volunteers or visitors who are ill with ILI symptoms isolate themselves at home and staff and volunteers should not return to work until they are feeling well and able to fully participate in all normal day to day activities. Staff and visitors who become ill while at work should isolate themselves in a separate room until they can leave the facility. It is recommended that ill residents be restricted to their room. If there are several ill residents, they may be cohorted in the same room. Staff movement between floors may be restricted.

Pharmaceutical measures

Use of antiviral drugs to control outbreaks of influenza in closed facilities is standard practice.  During an outbreak, early treatment (i.e. antiviral medications initiated less than 48 hours after onset of symptoms) is generally recommended for all cases in both residents and staff, especially those with risk factors for complications from influenza.^[2]In determining the appropriate prophylaxis strategy, consideration of the severity of illness, it’s transmissibility and the vulnerability of the resident population is indicated. Although older adults appear to be less susceptible to pH1N1 2009, once infected with pH1N1, persons aged 65 years and older have an increased risk of severe outcomes (ICU admission and/or death).  pH1N1 outbreaks in long term care facilities have been rare to date. When they have occurred, they have been mild with little transmission.  In the presence of mild disease with little transmission, prophylaxis may not be necessary and, post-exposure prophylaxis may only be indicated for those in the affected unit or geographic area. However, if there is sustained and widespread transmission, it may be indicated for the entire facility.  Medical directives, dispensing plans, advanced consent for the cognitively impaired, and institutional policies for staff illness can facilitate rapid outbreak control.  As the pandemic progresses, it may be necessary to develop protocols for quickly accessing antivirals from the National Antiviral Stockpile.

The antivirals that have been found to be effective for pH1N1 are oseltamivir (Tamiflu^®) for adults and children of all ages and zanamivir (Relenza^®) for adults and children age 7 and up. Oseltamivir is generally considered the first line treatment due to its systemic absorption and increased availability.  Zanamivir is inhaled and may be more difficult to administer to the cognitively impaired; it is not recommended for people with reactive airway disease.  Clinicians should refer to the appropriate product monograph for dosing and additional prescribing information^{[4] [5]}. For oseltamivir (Tamiflu^®) dosing recommendations for children under the age of one, refer to the Guidance for expanded use of Tamiflu^® for children under one year of age.

Reporting

Facility outbreak reporting

Facilities are advised to notify local public health whenever a respiratory outbreak is suspected and investigate the nature, extent and duration of the outbreak.  This includes initiating a line listing of all resident and staff cases by unit and/or geographic area of the facility.

Adverse event reporting

Reports of adverse reactions to antiviral medications are an important source of information that will help guide their safest and most effective use.  Any serious adverse reactions can be reported online at MedEffect Canada^[6] or by calling 1 866-234-2345.

DECLARATION OF THE END OF THE OUTBREAK

The MOH or designate declares an outbreak over when no new cases have occurred for 14 days after the onset of symptoms in the last case. This is to cover two incubation periods; the incubation period is currently under review.

References and resources: