influenza

Influenza: Time is of the essence

When it comes to influenza, time is of the essence - it's important to tackle the flu, before it takes hold.

Nearly one-in-ten Australian adults who are hospitalised with the flu end up in intensive care (ICU),1 with estimates suggesting the flu contributes to more than 3,000 Australian deaths each year.2

The 2017 record flu season saw more than 250,000 Australians infected by the flu virus, and 2019’s early flu season resulted in more than 115,000 reported flu cases by June.3

Infectious Diseases Paediatrician, Senior Professorial Fellow at Westmead Institute of Research and Immunisation Coalition Chairperson, Professor Robert Booy, Sydney researches the prevention, management and control of the flu virus.

    

Learn more about antivirals with Infectious Diseases Paediatrician and Immunisation Coalition Chairperson, Professor Robert Booy, Sydney.

    

“The flu doesn’t discriminate – it affects people of all ages, and infections among the elderly are more likely to require hospitalisation or cause serious complications, such as pneumonia and heart attacks. 

“The flu is a highly contagious disease. It is spread by people coughing or sneezing, or by touching contaminated surfaces,” says Prof Booy.

A sneeze can contain up to two million virus particles, which travel at 160 kilometres per hour, and can spread up to four metres.4 When they land on a surface, the particles can be picked up by anyone who touches that surface.

In fact, the flu virus can remain active for more than eight hours on hard surfaces, including handrails,5 and up to an hour in enclosed areas, such as train carriages.6 People with the flu can also be infectious from 24 hours before, to one week after symptoms first appear.7

“The onset of flu symptoms is typically sudden and severe, often including high fever, chills, cough (usually dry), sore throat, headache, body, muscle and joint aches, chest heaviness and fatigue," 8,9 Prof Booy says.

“The worst of the symptoms usually subside after eight days, although a cough or tiredness may last for several weeks.”10

 

    

“Most flu cases in Australia occur in the winter months between June and September, however you can contract the virus at any time of the year,”11 says Prof Booy.

Flu vaccination is the first line of defence against the virus,12 particularly for vulnerable groups like children, the elderly and pregnant women.13 However, vaccination cannot protect against all flu viruses, so antiviral therapy is an important component in treating and preventing the spread of flu.7

“Antivirals work specifically on influenza by attacking the virus and stop it either from multiplying or getting out of cells. So, they are a safe and effective treatment option for people with the flu,” Prof Booy says.

Early treatment with antivirals is especially important for people who are very sick with flu, and those at risk of serious complications.7 Antiviral treatment should be started as soon as possible, as it has been shown to limit the duration and severity of flu infection if taken within 48 hours of symptoms first appearing.7

“The earlier you get on top of the virus, the greater the benefit, so it’s recommended to take an antiviral promptly," Prof Booy says. 

For people who are hospitalised with more severe infections, antiviral treatment can be started up to 4-5 days after the onset of symptoms to reduce the risk of disease progression.7

Antiviral medications are different from antibiotics, which fight bacterial infections.3 Flu antivirals can be used against all known flu virus types and subtypes, including ‘bird flu’ and ’swine flu’ viruses, but not against any other respiratory viruses.7

Flu antivirals can also be used prevent the spread of the flu virus, with an effectiveness of 70 – 90 per cent.7

“If you’ve been in contact with someone who has the flu, or you start to feel unwell, it’s best to see your GP within 24-48 hours for the best chance at treatment,” Prof Booy says. 

“Early and effective treatment for the flu can make a difference between taking a few days off work and a week off work. For the more severe cases, it can even mean the difference between hospitalisation and serious illness.”

For more information on how to prevent the spread of flu, head to www.immunisationcoalition.org.au.

 

References

  1. Australian Government Department of Health, 2018 Influenza season in Australia - A summary from the national influenza surveillance committee. 2018. 
  2. Victorian State Government - Better Health Channel. Flu (Influenza). 2018; Available from: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/flu-influenza [Accessed: June 2019].
  3. Australian Government Department of Health. National Notifiable Diseases Surveillance System 2019; Available from: http://www9.health.gov.au/cda/source/rpt_3.cfm [Accessed: June 2019].
  4. Morawska. L, Johnson GR, Knibbs LD, Kidd TJ, Wainwright CE, Wood ME, Ramsay KA, et al. (2016) A Novel Method and Its Application to Measuring Pathogen Decay in Bioaerosols from Patients with Respiratory Disease. PLoS ONE 11(7): e0158763. https://doi.org/10.1371/journal.pone.0158763 [Accessed: June 2019].
  5. Bean B, Moore BM, Sterner B et al. Survival of influenza virus on environmental surfaces. J Infect Dis July 1982;146(1):47-51. 
  6. Knight V. Viruses as agents of airborne contagion [chapter V]. Annals of the New York Academic Sciences 1980;353:147-156 
  7. Immunisation Coalition. The 2018 influenza guide for general practitioners. Available at http://www.immunisationcoalition.org.au/wp-content/uploads/2018/03/Influenza_Mar18_WEB.pdf [Accessed: March 2018].
  8. Centers for Disease Control and Prevention (CDC). Cold versus Flu. 2019; Available from: https://www.cdc.gov/flu/about/qa/coldflu.htm [Accessed: June 2019].
  9. National Centre for Immunisation Research and Surveillance., Factsheet: Influenza vaccines. 2019; Available from: http://ncirs.org.au/sites/default/files/2019-03/Influenza-fact-sheet_Mar%202019_Final.pdf [Accessed: June 2019].
  10. Victorian State Government - Better Health Channel, Infections - bacterial and viral, 2018. Available from https://www.betterhealth.vic.gov.au/health/ConditionsAndTreatments/infections-bacterial-and-viral. [Accessed: June 2019].
  11. Queensland Government. Influenza (The Flu) 2018; Available from: http://conditions.health.qld.gov.au/HealthCondition/condition/14/217/82/influenza-the-flu [Accessed: June 2019].
  12. World Health Organisation (WHO). Influenza (Seasonal) fact sheet. 2018 March 2019]; Available from: http://www.who.int/mediacentre/factsheets/fs211/en/ [Accessed: June 2019].
  13. Centre for Disease Control and Prevention. Influenza (Flu): People at High Risk For Flu Complications. 2018 [cited 2019]; Available from: https://www.cdc.gov/flu/highrisk/index.htm?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fflu%2Fabout%2Fdisease%2Fhigh_risk.htm [Accessed: June 2019].