Your Complete Guide to Influenza

What is influenza?

Influenza (The Flu) is a viral infection that affects Australians across demographic and geographic spectrums. It can range in symptoms from mild aches and pains to death.

Australians more at risk of complications from an influenza infection are children, the elderly, Aboriginal and Torres Strait Islanders, people with immune system dysfunction and people with chronic medical conditions.

Influenza is highly contagious. It is spread by droplets (coughing, sneezing, talking) containing virus passing between people and from surfaces that have contaminated by virus (including tables, door handles, remote controls, money, hands, keyboards, benches, public transport).

Did you know that the influenza virus can last for longer than one hour in the air in enclosed environments, up to 5 minutes after it is transferred to environmental surfaces, up to 15 minutes after being transferred from tissues to hands and more than 8 hours on hard surfaces (metal and plastic)?

Influenza generally causes large numbers of infections in Australia during the winter months. The peak influenza season in Brisbane is generally between late July and September. Influenza symptoms generally occur from 1 -3 days after being infected. The most common symptoms are : fever, sore throat, aches and pains, fatigue, headache, dry cough.

Below is a table comparing the flu with a common cold.

* Resource

Why do we recommend vaccination against influenza?

There are many reasons to vaccinate against influenza.

• Primarily to provide protection to ourselves. Approximately 3000 Australians die of influenza related illness each year! In 2018 there were 58 570 cases of laboratory confirmed influenza in Australia. There were certainly more unconfirmed cases. It is estimated that more than 18 000 Australians are hospitalised each year for influenza related illnesses. More than 300 000 Australians visit their GP for influenza related consultations each year.

• To prevent the spread of influenza. Even if we are fit and healthy and only get a mild form of influenza infection we are infectious for 24 hrs prior to getting sick and up to 7 days after symptoms start. Influenza is highly infectious and preventing even one person from becoming infected by influenza will have a flow on effect of preventing hundreds of others from also being infected.

• To protect Australian’s who are not able to be vaccinated against influenza. Certain subsets of Australians are excluded from being vaccinated against influenza. Decreasing the overall cases of influenza in the community helps to protect these people.

• Providing protection to those Australians at most risk of developing complications of influenza. No vaccination is perfect. Even people vaccinated against influenza are susceptible to developing an infection. People with other health issues, immune system dysfunction and very young and elderly Australians are at most risk. Decreasing the number of overall influenza cases in the community via vaccination provides even further protection to these vulnerable Australians.

Why do we have to have a flu vaccination every year?

Influenza viruses are continually changing their appearance and therefore their ability to evade the immune system. They can change their appearance via 2 mechanisms – quickly (antigenic shift) and gradually (antigenic drift). It is this ability to change that makes vaccination against influenza so difficult and so important.

The World Health Organisation (WHO) tracks the patterns of influenza virus strains circulating globally. From this tracking they select strains that are most likely to cause infections in Australia each winter. This information is used to make a yearly influenza vaccination. Because influenza viruses change continually it is crucial to have a vaccination each year to provide the most up to date protection.

The continual change to the virus also means that our natural immunity that is created when we are infected with influenza does not give us life long protection and means that we can catch the flu more than once.

Some years the vaccination provides great immunity against seasonal influenza strains. Some years the virus changes or new strains cause infections that aren’t covered by the influenza vaccination. In 2018 the vaccination was made of exactly the strains that caused infections due the flu season, therefore the rate of infection, hospitalisation and death due to influenza related infection was lower during the years where the vaccination offered lower protection.

How do we prevent infection with influenza?

• Vaccination: get yourself and your family vaccinated, suggest vaccination to employees or colleagues. To ensure that the vaccination covers you during the peak influenza time in Brisbane vaccination from May onwards is recommended.

• Wash your hands! This prevents the spread of virus from others to you and also decreases the chance that you pass on the virus should you be infected without knowing.

• Stay home from work or school: you are infections for approximately 7 days after developing an influenza infection. To avoid sharing please don’t go to work or school.

• Keep viruses to yourself: use a tissue or the inside of your arm when you sneeze or cough to avoid passing on the virus. Throw away tissues and avoid using handkerchiefs.

• Keep 1 metre away: keep 1 metre away from someone who may have the flu. This helps prevent droplet spread of the virus to you.

• Clean surfaces: regular cleaning of common surfaces at home and at work will help prevent virus transmission.

What happens if I get influenza?

Most Australians recover from influenza within 1 week. Fatigue/tiredness and a cough may persist longer. Some people with lower immunity or other medical issues may develop complications such as pneumonia, heart complications, muscular complications and neurological complications. Influenza can affect your immunity and leave you more susceptible to other infections. Even healthy people may develop influenza related complications.

Each year different influenza strains will be different in the severity of illness that they cause and therefore the severity of the complications will differ. Rates of vaccination and the efficacy (or effectiveness) of the vaccination has an impact on the severity of the flu season each year.

The most effective treatment for influenza is rest and fluids. For more information read our Do I have flu? guide.

Please see your doctor at Hawthorne Clinic for more advice regarding the influenza vaccination and preventing influenza this season.

Resources:

https://www.cdc.gov/flu/about/viruses/change.htm

https://www.immunisationcoalition.org.au/immunisation/flu-facts/

http://www.health.gov.au/internet/main/publishing.nsf/Content/cda-surveil-ozflu-flucurr.htm/$File/2018-Season-Summary.pdf

https://www.health.qld.gov.au/__data/assets/pdf_file/0033/707649/influenza-qld-2018.pdf

http://conditions.health.qld.gov.au/HealthCondition/condition/14/217/82/influenza-the-flu