 Influenza – Backgrounder 2007 53.89 Kb
What is influenza?
- Influenza is a serious, usually
debilitating illness whose affects are felt throughout the whole body.
Symptoms include fever, headaches, muscle aches and pains.
- Even healthy young adults may take
several weeks to fully recover from influenza, and for some people it can
lead to hospitalisation or even death.
- Many people confuse the common cold
with influenza. However, colds are much less serious usually with
different symptoms and less potential for severe or life-threatening
illness.
How serious is seasonal
influenza?
- In the last century it has been
estimated that more people died from annual seasonal influenza than in the
three influenza pandemics,1 and twice as many Australians die
of influenza and pneumonia than in traffic accidents.2
- The World Health Organization (WHO)
estimates that worldwide there are between three and five million cases of
seasonal influenza each year and between 250,000 and 500,000 deaths.3
How does influenza
impact Australian healthcare systems?
- An ISG report estimates that each
year on average, influenza-like illness:4
-
Causes
18,000 hospitalisations
-
Requires
over 300,000 GP consultations
-
Costs
the Australian Government at least $85m - a cost that is largely preventable
and primarily borne by the Australian tax payer.
- Hospitalisations comprised 88
percent of the $85m cost4 and the majority of the 18,000
hospitalisations and consultations happen over a six week period when
influenza is most prevalent - therefore place a significant and intense
burden on healthcare resources.
- Healthcare resources can often be
further stretched as currently only around 20-50% of healthcare workers
are vaccinated against influenza. This not only puts them at risk of
contracting the disease, but also of spreading the disease to their
at-risk patients.
Who is at particular
risk of complications and hospitalisation from influenza?
- People at particular risk of severe
complications from influenza are those with heart conditions, asthma and
other lung conditions, diabetes, kidney problems, those with weakened
immune systems, residents of nursing homes and other long-term care
facilities, all Aboriginal and Torres Strait Island adults aged 50 years
and over, as well as anybody aged 65 and over regardless of their health
status.5
- Australia has had
great success in vaccinating people 65 years and over, with around 80% of
this age group getting vaccinated; however only 42% of people <65 with
at-risk conditions receive the annual influenza vaccination,6 and
in 2006 over 85% of recorded influenza cases in Australia were in those
under 65 years of age.7
- Studies have shown
that people with pre-existing conditions have a 40 times increased risk
of dying from influenza related complications and if they have both heart
and lung disease that risk is increased to 800 times.8
- In addition, it is important that
people who care for - or are in close contact with - people who are at
particular risk, also avoid infection to avert passing it on to them.
- Many otherwise healthy Australians
can't afford to get influenza, such as those who are self-employed, single
parents, carers or people who can't afford to take any time off work.
Falling victim to influenza could mean that important life events and
activities are missed, resulting in unnecessary suffering as well as
economic hardship for many Australians.
How can you reduce your
risk of catching influenza?
There are a number of
things people can do to protect themselves against influenza and the risk of
hospitalisation:
- Vaccination is the best way of
helping protect yourself against influenza
- Hand washing and personal hygiene,
such as trying not to touch your mouth or nose are also important
preventative measures
- Where possible, avoid crowds when
influenza is prevalent.
Note that in controlled trials remedies such as
vitamin C and echinacea have been shown to be ineffective in preventing
influenza.
- A
new vaccine is produced every year with an updated formulation to ensure that
Australians are given the best possible protection - the vaccine protects
people against three strains of influenza which the WHO identifies as the most
likely to cause outbreaks for that season.
- The
2007 Southern Hemisphere influenza vaccine includes the following influenza strains:
- A/New Caledonia
- A/Wisconsin
- B/Malaysia.
- No
vaccine is 100% effective; however influenza vaccination is very effective in
protecting against the severe consequences of infection. Studies have
convincingly shown it greatly reduces the cases of pneumonia, hospitalisation
due to respiratory illness and the total deaths occurring during an influenza
season.9
- For
most parts of Australia influenza vaccination
is best carried out in the autumn, before serious outbreaks can begin to occur.
The majority of infections occur between July-September.
- In
the far north of Australia influenza outbreaks can
occur early in the year and vaccination should be practiced as early as
possible.
- Many
people who should be vaccinated are not, because they believe being fit and
healthy will protect them against influenza. This is not the case.
What can you do if you
catch influenza?
-
There
are specific antiviral medications available on prescription which can help
limit the effect of influenza if they are taken early after the onset of
symptoms (within the first two days of the illness).
-
If
you think you are getting influenza and wish to reduce the time and severity of
your illness it's important that you see your GP immediately.
-
The
availability of treatments does not lessen the need for people to still get
vaccinated - it is important that all those in risk-groups, as well as others
who can't afford to get influenza, get vaccinated every year as their first
line of defence.
Avian influenza update:*
-
The
first human cases of the current H5N1 strain of bird flu, or avian influenza,
were reported in Vietnam in December 2003.
-
To
date there have been a total of 168 confirmed deaths from avian influenza
worldwide, with a majority of cases being reported from South East Asia and China.
-
Wild
birds infected with the H5N1 strain of avian influenza have been confirmed in
many European countries, and Turkey reported four deaths
caused by avian influenza in 2006.
-
All
evidence to date indicates that close contact with dead or sick birds is the
principle source of human infection with the H5N1 virus, and most human cases
have been traced back to contact with sick poultry. However, it is believed
that avian influenza could acquire the ability to pass from person to person and
therefore poses a potential pandemic threat.
-
Avian
influenza has not yet been found in Australia; however, it is
important that we remain vigilant, particularly due to our close proximity to Asia.
*Updated 7
March 2007
References:
1. Wilschut J & McElhaney J.E. Influenza.
Elsevier Limited. Spain. 2005. p15
2. Australian Bureau of Statistics. Causes of
death Australia 2003: 3303.0 p38-39
3. The Division of Communicable Disease Control.
Avian influenza newsletter. Issue 7: November 2005
4. Newall, A et al. Economic report into the
cost of influenza to the Australian health system. March 2007.
5. NHMRC. The Australian Immunisation Handbook 8th
Edition: 2003. Available at: http://www9.health.gov.au/immhandbook/ Last
reviewed: March 2006
6. Australian Institute of Health and Welfare.
2004 Adult vaccination survey. Available at: http://www.aihw.gov.au/publications/phe/avssr04/avssr04.pdf
7. Australian Department of Health and Ageing.
National Notifiable Diseases Surveillance System. Number of notifications of
influenza (laboratory confirmed), Australia, 2006 by age group and
sex. Cited 20/02/07. Available at: http://www9.health.gov.au/cda/Source/Rpt_5.cfm .
8. National Institute of Clinical Studies. Flu
Facts. Available at: http://www.fightflu.com.au/asp/index.asp?sid=2118&page=facts
9. Vu T et al. A meta-analysis of effectiveness of
influenza vaccine in persons aged 65 years and over living in the community. Vaccine
2002; 20: 1831-1836
Content Updated ( Wednesday, 14 March 2007 )
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