What you need to know to avoid illness
Here is what you need to know about Australian flu - and how to better protect yourself against it.
What exactly is flu?
It is a group of viruses that attach to the lining of the lungs. The symptoms of high fever, nausea, vomiting and diarrhoea are side-effects of inflammation caused as the immune system goes into overdrive to fight it off. The virus is divided into A, B, C and D categories, depending on its capacity for mutation and infection. Types A and B are the most dangerous to humans. The letters H and N in the strain refer to up to 18 types of haemagglutinin protein and 11 types of neuraminidase protein on the surface of the virus. These proteins affect the ability of the virus to attach itself to the lining of the lungs.
How is this Australian flu strain different?
The H3N2 type A strain - nicknamed Australian flu because of where its outbreak was first reported - is similar to the H3N2 Hong Kong flu that caused a pandemic in 1968, killing a million people. The Health Protection Surveillance Centre (HPSC) says iInfluenza B and A (H3N2) are currently the predominant viruses here with more influenza B than is usually observed at this time of year.
Why has Australian flu struck now?
Flu viruses travel around the world causing most infections in winter. Prof Robert Dingwall of Nottingham Trent University says it is not clear if Australian flu is causing more of a problem because it's more virulent, or whether we have lost resistance to it. Prof Wendy Barclay of Imperial College London says flu infections are worse in winter, but the reasons are not clear. It may be because the virus survives best in cold damp air. Australian flu also leaves the body susceptible to other strains, as well as other infections.
Is it too late to be vaccinated?
No: the current risk from Australian flu could continue for months. HPSC says you will develop antibodies within 10 to 14 days of receiving the jab.
Flu vaccinations - designed to protect against Australian flu as well as some other strains - are available to everyone aged over 65, and those with a long-term medical condition (such as chronic lung disease, heart disease, neurological disorders, neurodevelopmental disorders and diabetes). You should also speak to a GP if you have a weakened immune system - for example, due to chemotherapy.
Parents are also being urged to seek vaccination for their young children. Pregnant women, nursing home residents, healthcare workers and anyone with morbid obesity should also get immunised.
Are healthcare staff vaccinated?
Vaccination is currently voluntary, and the HSE has confirmed most healthcare workers had not received the vaccine.
What else can be done to avoid it?
Crowded indoor spaces - such as school classrooms and warm offices - are a particular risk. If you travel on public transport, use hand sanitising gel until you can wash your hands properly in warm, soapy water. If you must sneeze or cough in public, don't cover your mouth with a tissue, as virus particles can be transferred on to your hands. Instead, virologists say sneezing or coughing into the crease of your arm far reduces the likelihood of the contagion spreading.
Does the vaccine work?
The vaccine protects against the three strains of flu virus recommended by the World Health Organisation. If you have been vaccinated and you come into contact with the virus, antibodies will attack it and stop you from getting sick. It is tailored to specific strains of flu and is based on predictions. Historically, this has not proved terribly effective or accurate, with large numbers of vaccinated people often still developing flu.