An emergency doctor based at Calderdale and Huddersfield hospitals has warned Aussie flu is coming.
So what are the symptoms and is it worse than regular flu?
Yesterday, Dr Nick Scriven, a consultant in acute medicine at Calderdale Royal Hospital and president of the Society for Acute Medicine, said: "We are starting to report Australasian flu is beginning to appear, which is worrying.
“We are seeing a lot of flu like symptoms but as yet do not know if it is ‘normal’ or the Australasian strain."
Dr Scriven made the comments amid a deepening crisis in the NHS that has seen hospitals told to suspend all non-urgent operations and inpatient care until February, including day-case procedures and routine outpatient appointments.
HRI chiefs yesterday confirmed that more than two dozen operations had been cancelled.
In addition a number of wards are closed due to a "winter vomiting" norovirus outbreak.
Brits have been warned it could spark the worst flu outbreak in the country in 50 years, with thousands of cases possible.
he strain of the disease has affected up to 170,000 people in Australia - more than two-and-a-half times last year's total - with over 300 reported to have died.
This week Ireland saw its first deaths - 'no more than 10' - while the potentially killer strain has now been confirmed in parts of the UK too.
Public Health England's latest flu report, for the week up to Christmas Eve, reveals nine people have been admitted to intensive care or a high dependency unit with H3N2. Five more were in hospital.
The areas in which the cases were reported were not identified.
Some A&E units in the country were said to be "standing room only" after being inundated with people struck down by the illness.
But what is 'Aussie flu'? And what steps can you take to avoid it? Read below to find out.
What is Australian flu?
There are two main types of flu - A and B.
One of the strains of influenza circulating the UK this year is a type of A flu known as H3N2.
The particular strain of H3N2 flu that is affecting the UK is similar to the type that Australia suffered from earlier this year, during their winter.
Dr Richard Pebody, acting head of respiratory diseases at Public Health England, said: "In Australia they saw excess mortality and other hospitalisations and so on due to H3N2."
What are the symptoms?
Dr Pebody said the H3N2 influenza can cause problems for the elderly, and can particularly result in care home outbreaks.
The symptoms of H3N2 are similar to other strains of the flu, but can be more severe. They can include:
- Body aches
- Minor congestion
- Sore throat
- Vomiting and diarrhoea
How can you avoid getting the flu?
People have been urged to get a flu jab to protect themselves from the H3N2 strain.
The flu vaccine is the best protection we have, although because flu strains change, it needs to be done every year.
The flu jab is offered free to adults at risk, over-65s, pregnant women and children at risk aged six months to two years old, and a spray is offered to children up to four.
You can have the jab at your GP and some pharmacies. Serious side effects of the vaccine are rare.
Those who don't heed the advice and are diagnosed by a GP may be prescribed an anti-viral medication to treat their symptoms.
While it takes 10 to 14 days for the vaccine to take effect, Dr Pebody encouraged those who can take advantage of the NHS's free programme to do so.
It has been reported that the vaccine used in Australia wasn't as effective as hoped.
If you haven't been diagnosed but think you have the flu, you can speak to a pharmacist to find out if there are any over-the-counter medications you can take.
People can prevent the virus from spreading by washing their hands regularly, covering their mouth and nose with tissues or a sleeve when they cough or sneeze, and cleaning surfaces they suspect are infected.
What is the difference between flu and a cold?
The symptoms may be similar to a common cold, but flu tends to be more severe.
Flu tends to come on in a few hours, makes you feel exhausted and affects more than the nose and throat alone.
It can also lead to much more serious complications like pneumonia.
How can you treat flu?
Flu usually clears up by itself after around a week, but there are ways you can recover more quickly.
Rest, sleep, keeping warm, taking paracetamol or ibuprofen and drinking lots of water are all recommended.
GPs do not prescribe antibiotics as they will not relieve symptoms or help recovery.
You can seek advice most easily from a pharmacist, and are encouraged not to call 999 or go to A&E unless you develop sudden chest pain, have trouble breathing or start coughing blood.
Patients are advised to only go to their GP if their symptoms fail to improve after seven days, they are a child, over-65, pregnant or have a long-term medical condition or weakened immune system.
What are the experts saying?
Experts have warned that this year's strain of Aussie flu could be more dangerous than the 1968 flu pandemic that killed more than a million worldwide.
Public health expert Professor Robert Dingwall, of Nottingham Trent University, warned: "The reports from Australia suggest the UK might be in for the worst winter flu season for many years."
However, Public Health England said that it was not yet known whether the UK would be hit as hard as Australia.