Public Health management of human illness associated with avian influenza A(H7N9) virus: Interim guidance for containment when imported cases are suspected/confirmed in Canada
Table of Contents
The Public Health Agency of Canada, in collaboration with provincial/territorial public health authorities and other relevant federal government departments, has developed this document to provide guidance to public health authorities working at the federal/provincial/territorial (F/P/T) levels in the event that a case of human disease caused by avian influenza A(H7N9 )virus is identified within their jurisdictions.
The trigger for this guidance is a novel influenza virus causing human cases with limited human- to- human transmission detected somewhere in the world. This guidance would be used when a case of avian influenza A(H7N9) virus infection is suspected or confirmed in Canada.
The strategy outlined in this guidance is containment, i.e. to minimize opportunities for transmission to contacts and thus delay progression to a situation of sustained human transmission within the jurisdiction. This guidance remains relevant while the outbreak management objective is containment.
This guidance is based on current available scientific evidence and expert opinion and is subject to change as new information on transmissibility and epidemiology becomes available. It should be read in conjunction with relevant P/T and local legislation, regulations and policies. This document has been developed based on the Canadian situation and therefore may differ from guidance developed by other countries.
Background
Human illness caused by avian influenza A(H7N9) virus was first reported to the World Health Organization (WHO) by the Health and Planning Commission of the People’s Republic of China on March 31, 2013. To date, the illness has been contained geographically and sustained human-to-human transmission has not been demonstrated. For information regarding the PHAC’s current public health risk assessment associated with this illness, please see the PHAC’s Summary of Assessment of Public Health Risk to Canada Associated with Avian Influenza A(H7N9) Virus in China (Footnote 1).
Methods
The Public Health Measures Working Group (PHMWG), an F/P/T working group reporting to the F/P/T Respiratory Infection Disease Outbreak Investigation Coordinating Committee, was convened to develop recommendations for the public health case and contact management of human cases of avian influenza A(H7N9) virus infection. In developing this guidance, the PHMWG worked closely with the Influenza and other Respiratory Infectious Diseases F/P/T Working Group (for surveillance-related issues) and the Infection Prevention and Control Expert Working Group, and consulted relevant guidance (i.e. the PHAC’s risk assessment (Footnote 1), the Association of Medical Microbiology and Infectious Disease (AMMI) Canada (Footnote 2), and the WHO (Footnote 3)). Guidance developed for previous outbreaks (e.g. the 2003 Severe Acute Respiratory Syndrome outbreak and the 2009 H1N1 influenza pandemic) was reviewed, as was available relevant literature.
Case Management
Case definitions for human disease caused by avian influenza A(H7N9) virus, specifically for confirmed cases, probable cases and persons under investigation (PUI) and associated reporting requirements are available online. The public health management of confirmed cases, probable cases and PUI is outlined below.
RECOMMENDATIONS: CASE MANAGEMENT
(confirmed, probable and PUI cases)
Case management
- Clinical management of patients should be guided by the illness in the patient and other patient factors (e.g. age, body weight, comorbidities). For information regarding antiviral use in the context of avian influenza A(H7N9) virus infection, please consult AMMI Canada’s Interim Guidance for Antiviral Prophylaxis and Treatment of Influenza Illness due to Avian Influenza A(H7N9) Virus(Footnote 2).
- Conduct active daily monitoring (e.g. telephone contact) of the individual’s health status for duration of illness or until laboratory investigation has ruled out avian influenza A(H7N9) virus infection.
- Provide information regarding:
- illness care in the home;
- when/where to go for medical assessment, and instruct case to report travel history or contact history immediately upon presenting to a health care setting; and
- prevention of illness transmission (see infection prevention and control section below).
Guidance has been developed by the Canadian Critical Care Society on clinical management of persons with severe H7N9 illness
Guidance for the Management of Severe Acute Respiratory Infection in the Intensive Care Unit
Laboratory testing
- Facilitate laboratory testing in consultation with the provincial Public Health Laboratory (PHL).
- As per relevant laboratory guidance and identified protocols, ensure that appropriate specimens from a PUI are forwarded to the respective PHL. The PHL will then coordinate the submission of specimens to the National Microbiology Laboratory for confirmatory testing. Include exposure/travel history with specimens being sent. Refer to Protocol for Microbiological Investigations of Severe Acute Respiratory Infections (SARI) (Footnote 4) for details.
Infection prevention and control
- Acute health care setting: Consult Interim Guidance Avian Influenza A(H7N9) Virus: Infection Prevention and Control Guidance for Acute Care Settings (Footnote 5).
- Home care: In addition to routine practices, healthcare workers visiting in the home should use contact and droplet precautions, including a surgical/procedure mask and eye protection, when within two metres of the ill person. It is recommended that aerosol-generating medical procedures should not be carried out in the home setting.
- For patients, their caregivers and others in the living environment:
- The ill person should limit his/her contact with others to the extent possible; for example, stay in a different room if possible and if not, try to maintain a minimum distance of two metres.
- If the ill person cannot be separated from others, then the ill person should wear a surgical/procedure mask or cover his or her nose and mouth with tissues if possible while others are in the same room.
- All members of the household should adhere to good respiratory etiquette 1 and hand hygiene practices.
- Hand washing with plain soap and water is the preferred method of hand hygiene in the community, since the mechanical action is effective at removing visible soil and microbes. Where hand washing is not possible, use of alcohol -based hand rubs (with at least 60% alcohol) is recommended; however, alcohol-based hand rubs alone may not be effective at eliminating the influenza virus on hands that are visibly soiled.
- Shared spaces (e.g. kitchens, bathrooms) should be kept well ventilated (e.g. open windows).
- If direct contact care must be provided to the ill person, have the ill person cover his or her mouth and nose with tissues or, if available, a surgical/procedure mask. Discard tissues and disposable materials used to cover the nose or mouth, preferably in a plastic-lined, covered garbage can. Clean soiled cloths appropriately.
- The caregiver providing direct contact care to the ill person should wear a procedure/surgical mask or the best available protection against respiratory droplets and perform hand hygiene after contact.
- Direct contact with body fluids, particularly oral or respiratory secretions and stool, should be avoided. Use disposable gloves to provide oral or respiratory care, if possible. Perform hand hygiene following all contact.
- Anyone who is at high risk for complications of influenza should not care for or come in close contact with the ill person. Consult the National Advisory Committee on Immunization: Canadian Immunization Guide Chapter on Influenza and Statement on Seasonal Influenza Vaccine (Footnote 6) for those typically considered to be at high risk of complications from influenza.
- Persons caring for an ill family member should limit their contact with other people as much as possible and monitor themselves for any signs of illness.
- Other types of possible exposure to the ill person or contaminated items should be avoided. For example, avoid sharing toothbrushes, cigarettes, eating utensils, drinks, towels, washcloths or bed linen. Dishes and eating utensils should be cleaned with soap and water after use.
- High-touch areas such as toilets and bedside tables should be cleaned daily using regular household cleaners or diluted bleach (one part bleach to nine parts water); clothes and bedclothes, of ill persons can be cleaned using regular laundry soap and water.
1 Respiratory etiquette: measures to be taken when coughing or sneezing to reduce the spread of germs. These measures include covering of mouth and nose with own arm (elbow). If a tissue is used, disposing of it promptly and performing hand hygiene afterwards.
Travel
- The PHAC’s Office of Border Health Services will be involved in the reporting and case management of arriving or departing international passengers who may be PUIs, with the Quarantine officer notifying local public health authorities should such situations arise. Quarantine officers have no authority over domestic flights. PHAC’s Environmental health officers will provide information to the operator regarding the cleaning of the conveyance.
Contact Investigation and Management
Considering the identified trigger and associated objective for this guidance, it is expected that a reasonable effort will be put forth to identify close contacts of confirmed and probable cases occurring in Canada. The purpose of contact tracing for close contacts of confirmed and probable cases are:
- to better understand the epidemiology of this novel influenza virus;
- to identify any symptomatic contacts; and
- to reduce the amount of time between the onset of illness and case isolation in order to reduce the opportunity for transmission to others.
Note: should the contact develop symptoms within 10 days following last close contact with the case, the individual should be managed as a PUI.
A close contact is defined as a person:
- who provided care for the patient, including health care workers, family members or other caregivers, or who had other close physical contact;
OR
- who stayed at the same place (e.g. lived with or otherwise had close prolonged contact within two metres) as a probable or confirmed case while the case was ill (beginning 1 day prior to illness onset and continuing until resolution of illness).
RECOMMENDATIONS: CONTACT MANAGEMENT
(of probable and confirmed cases)
Contact management
- Active monitoring conducted by public health staff, ensuring that these individuals are contacted daily for the duration of the monitoring period, which is defined as 10 days from the last close contact.
Public health advice
- Advise close contact of case for 10 days following the last close contact or until the probable case no longer meets the case definition (for e.g., the laboratory investigation has ruled out avian influenza A(H7N9) virus infection), to:
- Self-monitor for the appearance of fever and the onset of influenza-like-illness symptoms, which include acute onset of respiratory symptoms, sore throat, arthralgia, myalgia, and prostration. Young children, the elderly and people who are immunocompromised may not develop a fever.
- Consider staying in an area where health care is readily accessible, if possible.
- Maintain good respiratory etiquette and hand hygiene practices.
- If sharing living arrangements with a non-hospitalized case, avoid close contact if possible and follow relevant advice provided under the case management section above. For information regarding antiviral prophylaxis for close contacts in the context of avian influenza A(H7N9) virus infection, please consult AMMI Canada Interim Guidance for Antiviral Prophylaxis and Treatment of Influenza Illness due to Avian Influenza A(H7N9) Virus(Footnote 2)
- Should symptoms develop, limit contact with others to the extent possible (e.g. stay home/return home) and notify local public health authorities.
Travel
- In the absence of sustained human-to-human transmission, and with no evidence of transmission occurring during travel, tracing contacts who were in proximity of cases who were symptomatic during a flight or while on other conveyances (e.g. train, bus) is not recommended at this time.