Influenza occurs globally with an annual attack rate estimated at five to 10 per cent in adults and 20 to 30 per cent in children. In Canada, influenza generally occurs each year in the late fall or winter months.

The tabs below offer health professionals key information about influenza vaccination, infection prevention and control, diagnosis, and treatment of seasonal influenza.

  • sudden onset of high fever, chills, cough and muscle aches
  • other common symptoms include:
    • headache
    • chills
    • loss of appetite
    • fatigue
    • sore throat
  • nausea, vomiting and diarrhea may also occur, especially in children

For local, provincial and national influenza surveillance information:

  • Obtain laboratory testing (nasopharyngeal swab collected in a respiratory virus collection kit) in all persons with suspected influenza who are admitted to hospital.
  • Influenza testing is not currently available through the Public Health Ontario (PHO) Laboratory for patients in ambulatory settings, including those at high risk for influenza complications or patients in emergency department settings who will not be admitted to hospital.
  • Coming soon: PHO’s November 2018 Respiratory Viral Testing Algorithm will be available on PHO’s Labstracts.
  • High-Dose Fluzone® is now publicly funded for seniors, age 65 years+
  • Quadrivalent vaccine is available for adults and children, ages six months and older

2018/2019 Universal Influenza Immunization Program (UIIP) Vaccines

Influenza Vaccines QIVs (Quadrivalent Inactivated Vaccines) Q-LAIV (Quadrivalent – Live Attenuated Influenza Vaccine) High-Dose TIV (Trivalent Inactivated Vaccine)
Age Eligibility 6 months and older 2 to 17 years 65 years and older
Trade Names FluLaval® Tetra, Fluzone® FluMist® High-Dose Fluzone®
Dosage 0.5 mL 0.2 mL

(0.1mL in each nostril)

0.5 mL
Route IM injection Intranasal spray IM injection
Common Allergens Thimerosal in multi-dose vial Arginine, gelatin, gentamicin

Influenza vaccine strains

  • A H1N1
  • A H3N2
  • B Victoria
  • B Yamagata lineage – added strain in quadrivalent

More Information

When caring for people with influenza or influenza-like illness, follow Provincial Infectious Diseases Advisory Committee’s Routine Practices and Additional Precautions in all Health Care Settings including:

  • droplet and contact precautions
  • facial protection (which may include a mask in conjunction with eye protection, or a face shield that covers eyes, nose and mouth) within two metres of a patient on droplet precautions
  • isolation in a single room or cohorted with another lab-confirmed case
  • continued precautions for five days after onset of illness

In addition, advise patients with influenza-like illness to stay home from work or school while ill, and to practise frequent hand washing and cough etiquette.

  • Report confirmed cases of influenza to Toronto Public Health.
  • Report respiratory infection outbreaks in institutions and public hospitals to Toronto Public Health.
  • To report call 416-392-7411 during business hours and 3-1-1 on evenings and weekends.