Influenza

Statutory notification alert

• Influenza viral infection is a notifiable infectious disease in Western Australia.
• See notifiable communicable disease case definitions (Word 1.29MB).
• Notifications should be made using the communicable disease notification form for metropolitan residents (PDF 214KB) or regional residents (PDF 213KB).
• For notification of regional residents see contact details of public health units.
• See also description of Statutory medical notifications in Western Australia.

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: Is recommended annually for any persons after 6 months of age. It is strongly recommended for: children; pregnant women; Aboriginal and Torres Strait Islander people aged ≥15 years; elderly; non-Aboriginal people ≥65 years, healthcare workers and people with certain health conditions; See Western Australian vaccination schedule and Australian Immunisation Handbook 10th edition, Department of Health (external site).
• 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

• Influenza infection national guidelines for public health units (external site)
• Western Australian vaccination schedule
• Communicable Disease Guidelines for teachers, child care workers, local government authorities and medical practitioners.
• Australian Immunisation Handbook 10th edition, Department of HealthAustralian Immunisation Handbook 10th edition, Department of Health (external site)

Notifiable disease data and reports

• Up-to-date Influenza notification data
• General infectious disease reports

Further information

• Influenza (flu) vaccine (Healthy WA)
• Influenza (flu) vaccine – what pregnant women need to know (Healthy WA)