Influenza

Key Messages

  • Immunization against seasonal influenza has been shown to reduce the number of hospitalizations and deaths.
  • In Ontario, laboratory testing for influenza is only available for hospitalized patients or in the context of institutional outbreaks. The specimen of choice for diagnosing influenza virus is the nasopharyngeal (NP) swab taken within the first four days of illness.
  • Laboratory testing for influenza is not available to community-based healthcare providers in Ontario. Empiric treatment with antivirals is recommended by AMMI in suspected influenza cases who are at high-risk of influenza complications or with progressive, severe, or complicated illness.
Local Epidemiology

To obtain the latest statistics on influenza:

To obtain the latest statistics on other circulating respiratory viruses:

  • In Ottawa, Ontario, and Canada: the Respiratory Virus Detection Surveillance System (published weekly on Wednesday). Ottawa-specific data is presented in Table 1 rows “Ottawa P.H.L.” and “CHEO - Ottawa”. This report also provides Ontario-level data in the Table 1 row “Province of Ontario”, and national data in row “CANADA”.

NOTE: the incidence of influenza and other respiratory viruses in the community is greatly under-reported because the majority of persons with influenza-like illness (ILI) do not seek medical care, and do not undergo (are not eligible for) laboratory testing.

Signs and Symptoms

Symptoms: include, but are not limited to:

  • New or worsening cough
  • Shortness of breath
  • Fever (may be absent in the elderly or immunocompromised)
  • Sore throat
  • Headache
  • Myalgia
  • Lethargy
  • Gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea) in some children

Duration of illness: In most people, illness resolves within five to seven days. Complications are most common in the very young and the elderly; death is most common in the elderly.

Patient resource: How to differentiate influenza from the common cold

Infection Prevention and Control (IPAC) Measures

Key IPAC measure to prevent transmission in clinical office settings:

  • Provide self-screening signage at the entrance to the clinic
  • Triage persons with cough & fever into a separate waiting room (or exam room) or keep at least 2 metres away from other clients; ask them to wear a surgical mask if they have a cough.
  • Make 70% alcohol-based hand-rub (ABHR), masks and tissues available in the waiting room.
  • Clean and disinfect horizontal surfaces in patient care areas between patients.
  • Clean and disinfect high-touch surfaces frequently throughout the day.
  • Make personal protective equipment (PPE: gloves, face shields, surgical masks) and ABHR available for staff at point of care.
  • Emphasize to staff the importance of hand hygiene including when leaving exam rooms.
  • Recommend that all clinical office staff receive their seasonal influenza immunization as soon as it is available (i.e., before the start of the influenza season)

Mode of transmission:

Influenza virus particles are easily spread by contact and droplets which are released from infected persons when they sneeze, cough, or talk.

Period of communicability:

People become infectious 24 hours prior to onset of symptoms; viral shedding in nasal secretions usually peaks during the first three days of illness and ceases within seven days but can be prolonged in young children, the elderly and those who are immunocompromised.

For more information about IPAC:

Guidelines for all healthcare settings: 

Diagnosis / Laboratory testing
  • In Ontario, laboratory testing for influenza is only available for hospitalized patients or in the context of institutional outbreaks.
  • Laboratory testing for influenza is not available to community-based healthcare providers in Ontario, except through the Canadian Sentinel Practitioner Surveillance Network. Join this network to receive timely results about your patients’ diagnoses and to help inform Canada’s and the WHO’s influenza vaccination policies.
an NP swab
  • The specimen of choice for diagnosing influenza virus is the viral nasopharyngeal (NP) swab taken within the first four days of illness.
  • Treat suspected influenza infection empirically with antivirals, especially in patients at high-risk of influenza complications.
Reporting to Public Health

Report all suspected and confirmed respiratory outbreaks in institutions (e.g., hospitals, LTCH, retirement homes, shelters) to Ottawa Public Health by calling 613-580-2424 extension 26325. After hours, on weekends, or holidays: call 3-1-1.

Please report all laboratory-confirmed influenza cases to Ottawa Public Health by calling: 613-580-2424, extension 24224 or fax 613-580-9640. After hours, on weekends, or holidays: call 3-1-1.

Management of Patients

Most people will fully recover from influenza without medical intervention or antiviral treatment. Influenza management focuses on rest, fluid intake, and symptom management if necessary. Symptomatic persons should be encouraged to remain at home (avoid school/work and social events) to avoid transmitting influenza to others, especially those at high risk of complications.

Who is recommended to receive antivirals?

Antiviral treatment with oseltamivir (Tamiflu®) or zanamivir (Relenza®) is recommended by AMMI  for influenza-like illness (ILI) if:

  • the illness is progressive, severe, or complicated, or
  • the patient is at high risk of influenza-related complications, or
  • the patient is hospitalized, or
  • the individual is involved in an institutional influenza outbreak.

People at high risk of influenza-related complications or hospitalization are:

  • Pregnant women.
  • People 65 years of age and older.
  • Children under 5 years of age.
  • Adults and children with the following chronic health conditions:
    • cardiac or pulmonary disorders (including bronchopulmonary dysplasia, cystic fibrosis and asthma);
    • diabetes mellitus and other metabolic diseases;
    • cancer, immune compromising conditions (due to underlying disease, therapy or both);
    • renal disease;
    • anemia or hemoglobinopathy;
    • neurologic or neurodevelopment conditions;
    • morbid obesity (body mass index [BMI] of 40 and over);
    • children and adolescents (age 6 months to 18 years) undergoing treatment for long periods with acetylsalicylic acid, because of the potential increase of Reye’s syndrome associated with influenza.
    • People of any age who are residents of nursing homes and other chronic care facilities.
    • Indigenous peoples.

For those with influenza, treatment with oseltamivir (Tamiflu®) or zanamivir (Relenza®) shortens the duration of the symptoms and reduces the risk of complications.

When to prescribe antivirals:

  • When influenza is circulating in the community, laboratory confirmation of influenza is not needed to begin antiviral treatment. Waiting for laboratory confirmation would delay initiation of therapy.
  • Ideally, antiviral treatment should begin as soon as possible within 48 hours of symptom onset.
  • For those at high risk for influenza complications, antiviral treatment can be considered even if more than 48 hours have passed since symptom onset.
  • For individuals with moderate, progressive, severe or complicated influenza-like illness, such as individuals who are hospitalized with influenza-like illness, use of antiviral medication is recommended, regardless of time from symptom onset.
How to prescribe antivirals for influenza:

 

Oseltamivir (Tamiflu®)

Zanamivir (Relenza®)

(5 mg per inhalation)

Dosage for treatment

75 mg twice daily for 5 days for adults.

See AMMI guideline for pediatric dosing.

Dose adjustments may be needed if person is known to have renal impairment; see AMMI guidelines.

2 inhalations twice daily (approximately 12 hours apart) for 5 days.

Dosage for prophylaxis (e.g., in the context of an institutional outbreak)

75 mg daily for 10 days for adults (or in an outbreak, until the outbreak is declared over).

See AMMI guidelines for pediatric dosing.

Dose adjustments may be needed if person is known to have renal impairment; see AMMI guidelines.

2 inhalations twice daily (approximately 12 hours apart) for 5 days.

Age authorized for use

1 year of age and older.

Can be considered on a case-by-case basis for those younger than 1 year of age.

7 years of age and over.

Contraindications

None.

See product monograph for additional details.

Underlying respiratory condition such as chronic obstructive pulmonary disease or asthma.

See product monograph for additional details.

PDF version

Source: Public Health Ontario (2017). Antiviral medications for influenza: Information for health care providers. Retrieved from: http://www.publichealthontario.ca/en/eRepository/Antiviral_Medication_Influenza_Fact_Sheet.pdf 

More resources on how to prescribe antivirals for influenza:

Management of Institutional Outbreaks

Report all suspected and confirmed respiratory outbreaks in institutions (e.g., hospitals, LTCH, retirement homes, shelters) to Ottawa Public Health by calling 613-580-2424 ex 26325 or call 3-1-1 during evenings, weekends and holidays. Ottawa Public Health will assist you with outbreak management.

Access OPH resources on Respiratory Outbreaks in Long-Term Care Facilities and Retirement Homes, including line lists, instructions for collecting NP swab, antiviral recommendations for facility residents during an outbreak, etc.

Other resources for outbreak management:

Immunization

Immunization is the most effective strategy to prevent and reduce the impact of influenza in our community. Influenza vaccine has been shown to reduce influenza-related complications, hospitalizations, and deaths. Ottawa Public Health supports your efforts to increase influenza vaccine uptake in your practice through vaccine delivery, and by providing you and your patients with information and resources.

 Influenza strains covered by the vaccine
The 2019-2020 seasonal influenza vaccines protect against the following influenza strains:

Quadrivalent vaccines:

  • A/Brisbane/02/2018 (H1N1) pdm09-like virus;
  • A/Kansas/14/2017 (H3N2)-like virus;
  • B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage); and
  • B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage).

Trivalent vaccine:

  • A/Brisbane/02/2018 (H1N1) pdm09-like virus;
  • A/Kansas/14/2017 (H3N2)-like virus; and
  • B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage).
Populations recommended to be immunized
National Advisory Committee on Immunization (NACI) statement for 2019-2020

Who is recommended to be immunized against influenza?

NACI recommends that all individuals aged 6 months and older be immunized against influenza. As per the 2019-2020 NACI statement, influenza immunization is particularly recommended for the following groups:

  • People at high risk of influenza-related complications or hospitalization:
    • All pregnant people.
    • Adults and children with the following chronic health conditions:
      • cardiac or pulmonary disorders (including bronchopulmonary dysplasia, cystic fibrosis and asthma);
      • diabetes mellitus and other metabolic diseases;
      • cancer, immune compromising conditions (due to underlying disease, therapy or both);
      • renal disease;
      • anemia or hemoglobinopathy;
      • neurologic or neurodevelopment conditions (includes neuromuscular, neurovascular, neurodegenerative, neurodevelopmental conditions, and seizure disorders [and, for children, includes febrile seizures and isolated developmental delay], but excludes migraines and psychiatric conditions without neurological conditions);
      • morbid obesity (body mass index [BMI] of 40 and over);
      • children and adolescents (age 6 months to 18 years) undergoing treatment for long periods with acetylsalicylic acid, because of the potential increase of Reye’s syndrome associated with influenza.
    • People of any age who are residents of nursing homes and other chronic care facilities.
    • People 65 years of age and older.
    • All children 6 to 59 months of age.
    • Indigenous peoples.
  • People capable of transmitting influenza to those at high risk:
    • Health care and other care providers in facilities and community settings who, through their activities, are capable of transmitting influenza to those at high risk of influenza complications.
    • Household contacts (adults and children) of individuals at high risk of influenza-related complications:
      • household contacts of individuals at high risk, as listed in the section above;
      • household contacts of infants under 6 months of age as these infants are at high risk of complications from influenza but cannot receive influenza vaccine;
      • members of a household expecting a newborn during the influenza season.
    • Those providing regular child care to children 59 months of age and under, whether in or out of the home.
    • Those who provide services within closed or relatively closed settings to persons at high risk (e.g., crew on a ship).
  • Others:
    • People who provide essential community services.
    • People in direct contact during culling operations with poultry infected with avian influenza.

How many vaccine doses are required?

Children 6 months to under 9 years of age receiving seasonal influenza vaccine for the first time in their life should be given two doses, with a minimum interval of four weeks between doses. All others require only one dose annually.

Contraindications to influenza immunization

Influenza vaccine is contraindicated in:

  • Persons who have developed Guillain-Barré Syndrome (GBS) within six weeks of influenza vaccination.
  • Persons who have developed an anaphylactic reaction to a previous dose of influenza vaccine or to any of the vaccine’s components, except for egg.
  • Egg-allergic individuals may be vaccinated against influenza without prior influenza vaccine skin test and with the full dose, irrespective of a past severe reaction to egg, and without any extraordinary precautions, but ensuring that, as with all vaccine administration, immunizers be prepared with the necessary equipment, knowledge and skills to respond to a vaccine emergency always.
  • In situations of suspected hypersensitivity or non-anaphylactic allergy to a vaccine or its components, investigation is indicated which may involve immunization in a controlled setting. Consultation with an allergist is advised.

For more information, please consult the product monographs:

Influenza Vaccine Abbreviations
  Quadrivalent Inactivated Vaccine High-Dose Trivalent Inactivated Vaccine
Universal Influenza Immunization Program (UIIP) Abbreviation QIV High-dose TIV
New National Advisory Committee on Immunization (NACI) Abbreviation IIV4-SD IIV3-HD

 

NACI vaccine product recommendations
National Advisory Committee on Immunization (NACI) statement for 2019-2020 

Influenza vaccine is recommended for everyone 6 months of age and older who does not have contraindications to the vaccine.

Recipient by age group Vaccine types available for use in Ontario Recommendation
Individuals 6 months to 64 years of age
  • QIV (IIV4-SD)

 

QIV (IIV4-SD) is authorized for use in this age group. 

NACI recommends that, given the burden of influenza B disease in  young children, QIV(IIV4-SD) should be used. 

Afluria®Tetra influenza vaccine is indicated for persons 5 years of age and older only. 

Adults 65 years of age and older  
  • QIV (IIV4-SD)
  • High-dose TIV (IIV3-HD)
 

Either QIV (IIV4-SD) or high-dose TIV (IIV3-HD) may be used in this  age group.

See below for key considerations when choosing between QIV (IIV4-SD) and high-dose TIV (IIV3-HD). 

Pregnant people  
  • QIV (IIV4-SD)
QIV (IIV4-SD) is recommended for all pregnant people.

Choosing between QIV (IIV3-SD) and High-Dose TIV (IIV3-HD) for patients 65 years of age and older

The high-dose TIV (IIV3-HD) contains three influenza strains: two A strains (H1N1 and H3N2) and one B strain. Studies have shown that the high-dose TIV (IIV3-HD) provides better protection against the influenza A(H3N2) strain in individuals who are 65 years of age and older compared to the standard-dose TIV formulations. A(H3N2) is associated with greater disease burden in individuals 65 years of age and older.

The high-dose TIV (IIV3-HD) contains a higher amount of antigen per strain than standard-dose influenza vaccine formulations. The high-dose TIV (IIV3-HD) contains 60 μg of hemagglutinin (HA) protein for each of the three vaccine strains compared to 15 μg of HA per strain in a standard dose vaccine, such as QIV (IIV3-SD). Studies have shown that the higher antigen content improves the immune response and improves how well the vaccine works compared to standard dose TIV, which is important since older individuals may not respond as well to influenza vaccines compared to younger individuals.

The QIV (IIV4-SD) offers protection against the same strains contained in the high-dose TIV (IIV3-HD) formulation with additional protection against a second influenza B strain. Relative to A(H3N2), influenza B occurs much less commonly in individuals 65 years of age and older.

Currently, there is insufficient evidence to directly compare the high-dose TIV (IIV3-HD) and QIV (IIV4-SD) products.

Given the options available for vaccination for those 65 years of age and older, it is important to discuss the specifics of each available vaccine to assist the individual in their decision making. Delaying vaccination in order to wait for a specific product is not recommended. Both QIV (IIV4-SD) and high-dose TIV (IIV3-HD) protect against the flu, and the most important thing is for seniors to be vaccinated.

Vaccine products publicly-funded in Ontario

Quadrivalent influenza vaccine (QIV or IIV4-SD) is publicly-funded for children and adults aged 6 months and older

For individuals aged six months and older, quadrivalent inactivated vaccines are available: Fluzone® Quadrivalent and FluLaval® Tetra (subject to availability).

For individuals aged 5 years and older, a quadrivalent inactivated vaccine is available: Afluria® Tetra (subject to availability).

Flumist® Quadrivalent, a live attenuated quadrivalent influenza vaccine given as a nasal spray, will not be available in Canada for the 2019/2020 influenza season.

High-Dose Trivalent influenza vaccine (high-dose TIV or IIV3-HD) is publicly-funded for adults aged 65 years and older

For individuals aged 65 years and older, a high-dose trivalent vaccine (Fluzone® High-Dose) is available. Fluzone® High-Dose will be available through primary care providers (e.g. physicians and nurse practitioners), participating retirement homes, long-term care homes, hospitals and at Ottawa Public Health community flu clinics. Fluzone® High-Dose will not be available through pharmacies.

Vaccine FluLaval® Tetra Fluzone® Quadrivalent Afluria® Tetra Fluzone® High-Dose
Influenza Vaccine Formulation Quadrivalent Inactivated Vaccine (QIV or IIV4-SD) Quadrivalent Inactivated Vaccine (QIV or IIV4-SD) Quadrivalent Inactivated Vaccine (QIV or IIV4-SD) High-Dose Trivalent Inactivated Vaccine (High-Dose TIV or IIV3-HD)
Dosage and Route of Administration 0.5mL IM

0.5mL IM

0.5mL IM 0.5mL IM
Format Multi-dose vial

Multi-dose vial (MDV)

Prefilled syringe (PFS)

Prefilled syringe Prefilled syringe
Eligibility for publicly-funded vaccine 6 months and older 6 months and older 5 years and older 65 years and older
Potential Allergens
  • Egg Protein*
  • Thimerosal**
  • Egg Protein*
  • Thimerosal (multi-dose vial only)**
  • Egg Protein*
  • Neomycin
  • Polymyxin B
  • Egg Protein*

* Egg allergy is not a contraindication to receiving the influenza vaccine (see National Advisory Committee on Immunization Influenza Statement).

** Nominal supply of thimerosal free, single-dose prefilled syringe of Fluzone® Quadrivalent vaccine is available for those 6 months of age and over who have known thimerosal allergies.

Important note: Fluzone® Quadrivalent and Fluzone® High-Dose are different products. Fluzone® High-Dose is only authorized for those 65 years of age and older. Please use caution when administering Fluzone® products to ensure that the right vaccine is being administered to the right person.

Vaccine ordering and pick up
Vaccine Distribution Room hours are Monday to Friday, 8 am to 4 pm. NOTE: November 11 is a statutory holiday and the Vaccine Distribution Room will be closed.
  1. Starting November 1, 2019, Ottawa Public Health will start accepting orders for additional quantities of influenza vaccine. Use the Influenza Vaccine Order Form 2019/2020 from Ottawa Public Health to order vaccine (not the Ministry of Health form). Please note: The Influenza Vaccine Order Form 2019/2020 will be available on our website as of November 1, 2019.
  2. Place your order using the number of doses required. Orders will be filled in the order in which they are received, with priority to high-risk groups. A predetermined amount of vaccine will be shipped in October to vaccinate high- risk patients. Additional flu orders can be placed after Nov 1st. Please allow up to 5 business days for your order to be processed.
  3. Always reserve some vaccine for persons age 65 years and older, and persons under 65 with medical conditions that put them at high risk for influenza-related complications.
  4. Your clinic/facility will be called when your order is ready. Arrange to pick up your order within 48 hours of notification at the Ottawa Public Health Vaccine Distribution Centre, on the ground floor of 100 Constellation Drive.
  5. Bring your own cooler and ice pack.
Vaccine that is not used by your clinic/facility cannot be redistributed. To reduce vaccine wastage, only order the quantity that you are sure to use within the month. You can order more vaccine as needed. Return unused vaccine to the Ottawa Public Health Immunization Program once you are finished immunizing for the season using Ottawa Public Health Vaccine Return Form
Report of adverse events following immunization (AEFI)
All adverse events following administration of an influenza vaccine must be reported to Ottawa Public Health within 24 hours by fax to 613-580-9660 using the AEFI reporting form.

More information about what constitutes an AEFI can be found here. If you have any questions related to the reporting of adverse events following immunization, please call 613-580-6744 and select “1” for English then “2” for healthcare provider; your call will be prioritized for answer by the next available public health nurse.

Health care agencies and workplaces providing influenza vaccine clinics
Ottawa Public Health seeks to support you in your efforts to increase influenza vaccine uptake in your facility or workplace by offering information and resources.

In you cannot find the information you seek here, please call 613-580-6744 and select “1” for English then “2” for healthcare provider; your call will be prioritized for answer by the next available public health nurse.

Information from the Ministry of Health on the 2019/2020 Universal Influenza Immunization Program (UIIP) is also available.

Return unused vaccine to the Ottawa Public Health Immunization Program once you are finished immunizing for the season using Ottawa Public Health Vaccine Return Form.

More information
  • Ministry of Health (MOH)
  • Ottawa Public Health
    • Information about influenza for healthcare providers
    • To order vaccine fax the influenza vaccine order form to 613-580-2783
    • For questions regarding a vaccine order email vaccine@ottawa.ca  or call 613-580-6744 and follow prompts for the Vaccine Distribution Centre.
    • Fax the Adverse Event Following Immunization (AEFI) reporting form to 613-580-9660
    • Hospitals, long-term care, retirement homes call the outbreak reporting line 613-580-6744 ext 26325 to report outbreaks
    • Workplaces call 613-580-6744 and select “1” for English then “2” for healthcare provider; your call will be prioritized for answer by the next available public health nurse.
    • Influenza vaccine manufacturers’ contact information:
      • Sanofi Pasteur (Fluzone® Quadrivalent and Fluzone®High-Dose) 1-888-621-1146
      • GlaxoSmithKline, Inc. (FluLaval®Tetra) 1-800-387-7374
      • Seqirus (Afluria®Tetra) 1-855-358-8966

 

Patient Information

Patient information is available at: OttawaPublicHealth.ca/Flu

Physician Resources

Surveillance reports:

IPAC:

Prescribing antivirals for influenza:

Outbreak management:

Immunization:

Contact Us

If you want to notify Ottawa Public Health about a suspected or confirmed respiratory outbreak in an institution, please contact us at 613-580-2424, extension 26325 or call 3-1-1 during evenings, weekends and holidays.

If you want to notify Ottawa Public Health about a laboratory-confirmed case of influenza, please contact us at 613-580-2424, extension 24224 or call 3-1-1 during evenings, weekends and holidays.

Contact Us