Influenza

Statutory notification alert

Public health management

Important information

  • Infectious agent: Influenza virus, mainly types A, B and C and many subtypes and strains.
  • Transmission: Influenza viruses are mainly spread by droplets made when an infected person coughs or sneezes. Influenza can also be spread through touching surfaces where infected droplets have landed.
  • Incubation period: Usually 1 to 3 days.
  • Infectious period: People with influenza can be infectious from the day before their symptoms start. Adults are most infectious in the first 3-5 days of their illness, while children remain infectious for 7-10 days, and people with weakened immune systems may be infectious for longer.
  • Case exclusion: Recommend cases exclude themselves until symptoms resolve.
  • Contact exclusion: Do not exclude.
  • Treatment: Generally bed rest and symptomatic treatment. Specific influenza antiviral medicines can reduce the severity and the duration of influenza if taken soon after onset of symptoms.
  • Immunisation: Annual influenza vaccination is recommended for all people aged > 6 months. It is strongly recommended, and free, through the National Immunisation Program and WA state-funded programs for: children aged > 6 months up to 5 years; Aboriginal and Torres Strait Islander people aged > 6 months; pregnant people; people aged ≥65 years, healthcare workers and people with certain health conditions; See Influenza Immunisation, Western Australian Immunisation Schedule and Australian Immunisation Handbook.
  • Case follow-up: Public health action focuses on outbreaks in high-risk settings such as health care facilities, special schools, residential care facilities, and Aboriginal communities.

Guidelines

Notifiable disease data and reports

Further information

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Public Health