Emergency Planning and Preparedness
Avian Influenza A(H7N9) Virus Guidance for Health Workers and Health Sector Employers
Last reviewed: June 8, 2015
Last updated: June 13, 2013
This information is intended for use by health workers and health sector employers in all settings.
The Ministry of Health and Long-Term Care has also developed general information on the avian influenza A(H7N9) virus.
- The Ministry of Health and Long-Term Care (ministry) has changed the time period between exposure and illness from 10 to 14 days in the case definition.
- The ministry has clarified the exposure criteria as part of the case definitions. Exposure criteria only apply to patients who have traveled to countries with known transmission of the avian influenza A(H7N9) virus and not countries with imported cases. At this time, China is the only country where transmission of the avian influenza A(H7N9) virus has been confirmed and is known to be circulating in animals.
- The ministry has clarified that health workers should use Routine Practices with Contact, Droplet and Airborne Precautions. Among other things, this means health workers are to use a fit-tested, seal-checked N95 respirator when at risk of exposure to a person under investigation, a probable or a confirmed case, such as when in the same room, when transporting the patient, or in other situations when they are within two metres of the patient.
- The ministry has included infection prevention & control recommendations in health care settings for visitors of confirmed cases, probable cases and persons under investigation.
- The ministry has included treatment recommendations for low-risk patients.
Confirmed Case : A patient fitting appropriate exposure criteria† and with avian influenza A(H7N9) virus infection that is confirmed by a laboratory
Confirmatory lab tests may take up to seven days from the time of specimen submission.
Probable Case : A patient fitting appropriate exposure criteria† and with acute respiratory illness or other symptoms compatible with influenza, regardless of illness severity, for whom laboratory diagnostic testing is positive for influenza A but un-subtypeable (i.e., negative for H1pdm09, negative for seasonal H1and negative for seasonal H3 by real-time reverse transcriptase polymerase chain reaction (RT-PCR)).
Person Under Investigation : A patient with acute respiratory illness or other symptoms compatible with influenza, regardless of illness severity, meeting any of the exposure criteria† and for whom laboratory confirmation is not known or pending, or for whom test results do not provide a sufficient level of detail to confirm avian influenza A(H7N9) virus infection.
†Exposure Criteria : A patient who has recently arrived (within 14 days of illness onset)from a country where transmission of avian influenza A(H7N9) virus has been confirmed or where avian influenza A(H7N9) viruses are known to be circulating in animals. OR
- a patient who has had recent close contact (within 14 days of illness onset) with a confirmed or probable case with avian influenza A(H7N9) virus.
Any person who has had close contact2 with a probable or confirmed case while the probable or confirmed case was ill should be carefully monitored for the appearance of respiratory symptoms. If symptoms develop within the first 10 days after contact, the individual should be considered a person under investigation and investigated accordingly.
The ministry will provide updated information about the country(ies) where human transmission of this virus has occurred or where this virus is circulating in animals. This information will be on its avian influenza webpage in the What’s New? section.
Health care providers should note that the ministry’s case definitions for avian influenza A(H7N9) virus differ from those provided by the Public Health Agency of Canada (PHAC). PHAC has provided a case definition that only includes severe acute respiratory infection, while the ministry’s case definition is broader to ensure a wider range of individuals are tested.
Occupational Health & Safety and Infection Prevention & Control
The ministry is recommending that health workers who are at risk of exposure to confirmed cases, probable cases or persons under investigation (when in the same room as a patient with influenza-like illness (ILI), when transporting a patient with ILI, or in other situations when they are within two metres of a patient with ILI) use Routine Practices with Contact, Droplet and Airborne Precautions. These measures include :
- hand hygiene
- use of airborne infection isolation rooms when possible
- masking the patient with a surgical mask when outside of an airborne infection isolation room
- use of gloves, gowns, fit-tested, seal-checked N95 respirators and eye protection .
For more information about measures used in Routine Practices and Contact, Droplet and Airborne Precautions, see the Provincial Infectious Diseases Advisory Committee’s (PIDAC's) Routine Practices and Additional Precautions in All Health Care Settings.
The use of Airborne Precautions is a higher level of precaution than is being recommended by PHAC. It is also a higher level of protection than normally recommended for seasonal influenza. The ministry is recommending Airborne Precautions based on its application of the precautionary principle to this novel virus for which little information about transmission and clinical severity is available.
Infection Prevention & Control for Visitors
Health sector employers should implement Routine Practices with Contact and Droplet Precautions for visitors of confirmed cases, probable cases and persons under investigation in health care settings, as per PIDAC's Routine Practices and Additional Precautions in All Health Care Settings. This includes :
- risk based education about hand hygiene and the use of personal protection equipment as described under Routine Practices
- masks for visitors who must be within two metres of patients
Visitors should be kept to a minimum and must be informed about the reason for implementing infection prevention and control measures.
Assessment, Testing and Treatment
It is recommended that health care providers assess, test and treat patients who meet the definition for confirmed and probable cases or persons under investigation as outlined below. The majority of avian influenza A(H7N9) virus cases reported to date have experienced severe respiratory illness; however, there have been some with milder illness.
Health care providers should assess patients presenting with acute respiratory illness or other symptoms compatible with influenzas using the case definitions and clinical judgment.
When indicated, antiviral treatment is most effective when started as soon as possible after influenza illness onset. Early initiation of treatment provides a better clinical response, although treatment of moderate, severe, or progressive disease started 48 hours after symptom onset may still provide benefit.
The ministry recommends that all confirmed and probable cases should be treated with antiviral medications, as outlined below. Persons under investigation (PUI) should be assessed and treated in accordance with the guidelines from the Association of Medical Microbiology and Infectious Disease Canada (AMMI), entitled Interim Guidance for Antiviral Prophylaxis and Treatment of Influenza Illness due to Avian Influenza A(H7N9) Virus [PDF].
Probable cases and persons under investigation are candidates for laboratory testing for influenza using RT-PCR.
The following specimens should be collected on all patients being tested for avian influenza A(H7N9) virus:
- respiratory tract samples (e.g., nasopharyngeal (NP) swab plus bronchoalveolar lavage (BAL) when possible); lung tissue if obtained (e.g. biopsy, post-mortem)
- a viral throat swab (placed in viral transport media) should also be collected on all hospitalized patients (see below)
- acute (when patient first seen with acute respiratory illness) and convalescent (21 to 28 days after illness onset) serology
Specimens from such patients should only be inoculated into viral culture in a level 3 laboratory. The avian influenza A(H7N9) virus is detected as influenza A in the current influenza A PCR assay used by the Public Health Ontario Laboratories (PHOL) and is un-subtypeable when subtyping is performed.
For avian influenza viruses for which data are available (i.e., influenza A H5N1), posterior pharyngeal (throat) swabs provide the highest yield upper respiratory tract specimens. For this reason it is recommended that a throat swab also be collected from hospitalized patients. Throat swabs should be submitted in viral transport media.
PHOL performs influenza A and B PCR; PHOL may also use a multiplex respiratory viral PCR (MRVP) assay to detect other viruses on hospitalized patients (viral culture is not routinely performed).
Testing for common bacterial respiratory tract pathogens (e.g., Mycoplasma pneumoniae, Chlamydophilapneumoniae, Legionella species) and consideration of fungal testing is recommended for hospitalized patients with evidence of lower respiratory tract infection in addition to testing for influenza.
Persons under investigation with severe respiratory illness (including radiographically-confirmed pneumonia, acute respiratory distress syndrome or other severe respiratory illness) of unknown etiology may be prioritized for diagnostic testing.
Serology testing is being done by the National Microbiology Laboratory (NML) to facilitate better understanding of the epidemiology of the novel virus and is not intended to inform clinical care. These results may take significant time (i.e., months) to be reported.
Health care providers should submit samples using PHOL's general test requisition form as follows:
- include the patient's health insurance number (HIN), date of illness onset, patient setting, travel history (including city/ province visited in China when possible), animal contact, signs and symptoms and specify "ARI – recent travel to China" on the requisition
- contact PHOL Customer Service Centre at (416) 235-6556 / 1-877-604-4567 prior to submission
- package and ship the primary clinical samples to the local PHOL following Category B/UN 3373 Transportation of Dangerous Goods instructions
PHAC and the Canadian Food Inspection Agency have released a Joint Biosafety Advisory on avian influenza A(H7N9) virus to assist clinical/ diagnostic and research laboratories in implementing proper biosafety procedures when handling samples containing avian influenza A(H7N9) virus.
For more information, call the Ministry of Health and Long-Term Care's Health Care Provider Hotline at 1-866-212-2272.
For additional information on worker health and safety information, please visit the Ministry of Labour Health and Community Care website.
This information does not relieve employers of their legislated obligations.
1 To date, China is the only country where transmission has been confirmed. Testing is not recommended for patients who have traveled to countries with imported cases from China, where infection likely occurred in China.
2 Close contact includes :
- anyone who provided care for the patient, including a health worker or family member, or who had other similarly close physical contact
- anyone who stayed at the same place (e.g., lived with, visited) as a probable or confirmed case while the case was symptomatic