Influenza: Everything You Need to Know This Flu Season
Published: 23 May 2023
Published: 23 May 2023
In 2023, there have already been over 40,000 influenza infections - with more than 8,000 of these cases being diagnosed in a single fortnight (DoHaAC 2023).
So, how can you best protect yourself this flu season?
Influenza (known colloquially as ‘the flu’) is a highly contagious, viral respiratory infection (Mayo Clinic 2022).
Influenza infection in humans is most commonly caused by either type A or type B influenza viruses, and there are many sub-types and strains within each of these categories (NSW Health 2023).
Due to being highly transmissible, influenza often causes seasonal, widespread illness. In Australia, flu season typically lasts from April until September (Better Health Channel 2023).
On average, there are approximately 5,100 hospitalisations and 100 deaths caused by influenza every year in Australia (AIH 2023).
The symptoms of influenza can range from mild to serious illness with potentially life-threatening complications such as pneumonia, and can even result in death - even in people who are otherwise healthy (Better Health Channel 2023; AIH 2023).
Influenza is a vaccine-preventable illness (NSW Health 2023).
Influenza is spread through the respiratory fluids (from coughs and sneezes) of people who are infected with an influenza virus (Better Health Channel 2023).
It can be transmitted by:
(Healthdirect 2022)
People with influenza may be infectious from 24 hours prior to the onset of symptoms until one week after the onset of symptoms (although children and immunocompromised people might be infectious for longer) (Queensland Health 2023).
In 2020, there were 21,266 notified cases of influenza in Australia and 37 deaths (DoHaAC 2020), and in 2021, just 598 cases and no recorded deaths at all (DoHaAC 2021).
Yet, in 2022, there were 225,000 cases of influenza - almost double the five year average (DoHaAC 2022).
The dramatic reduction in influenza cases during 2020 and 2021 can be largely attributed to the public health measures taken in response to the COVID-19 pandemic, which indirectly reduced influenza transmission (AIHW 2021). These measures included:
(Sonic HealthPlus 2021)
However, most of these restrictions that were put into place have now been rescinded, increasing people’s contact with one another and, consequently, the likelihood of spreading influenza (and COVID-19) within the community.
Influenza often has a rapid onset of symptoms, which may include:
(Better Health Channel 2023; AIH 2023)
The typical timeline of symptoms is:
Day 1-3 |
|
Day 4 |
|
Day 8 |
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(Better Health Channel 2023)
In some cases, influenza can cause potentially severe complications, including:
(AIH 2023; Mayo Clinic 2023)
Those identified as being at increased risk of contracting influenza and/or experiencing severe illness from influenza include:
(AIH 2023)
Influenza can be diagnosed through a polymerase chain reaction (PCR) test wherein in a swab is taken from the nose and/or mouth (NSW Health 2023).
Mild cases of influenza will typically resolve on their own without treatment (Healthdirect 2022). Patients should be encouraged to rest, drink adequate fluids, take paracetamol to manage pain and fever, and use decongestant medicines to relieve their symptoms (Better Health Channel 2023).
Prescription antiviral medicines (such as oseltamivir) may be considered in patients who are moderately or severely ill or are at higher risk of serious illness from influenza (Immunisation Coalition 2021).
In more serious cases, patients may require admission to hospital (Better Health Channel 2023).
Vaccination is one of the best ways to prevent influenza (Better Health Channel 2023).
While the vaccine can’t guarantee prevention, it does provide a high level of protection against influenza and reduces the risk of severe illness if infection does occur (Better Health Channel 2023).
The Australian Immunisation Handbook (2023) states that all people aged 6 months and over should receive an influenza vaccine every year. This is because:
(AIH 2023)
Under the National Immunisation Program, certain vulnerable groups are eligible to receive the influenza vaccine for free.
Note: The influenza vaccine can be co-administered with a COVID-19 vaccine (AIH 2023).
The following signs and symptoms in a person with influenza require Immediate medical attention:
(Better Health Channel 2023; Mayo Clinic 2023)
Despite the low rates of influenza in 2020 and 2021, cases are now back to pre-pandemic numbers. The best way to protect against influenza and reduce the risk of serious illness is via immunisation.
Keep up-to-date with the latest influenza surveillance information on the Department of Health and Aged Care website.
Question 1 of 3
What kind of illness is influenza?