As 2018 dawns, warnings have been issued that a potentially deadly virus being referred to as 'Aussie flu' has arrived in the UK.
Public Health's latest flu report shows growing numbers of cases reported in the past two weeks by GPs and hospitals, with hospitals urged to brace themselves for more cases this winter.
Australia was hit by one of the largest outbreaks it had seen in years in the southern hemisphere’s winter.
It was blamed for hundreds of deaths and there are fears that the particularly prevalent strain of Aussie flu, H3N2, could be spreading to the UK.
The strain mainly affects older people, those with long-term health conditions, pregnant women and children.
What are the symptoms?
The symptoms of most flu, including H3N2, are similar, but different strains can be more severe or contagious than others.
Symptoms can include a sudden fever, aches, exhaustion, a dry chesty cough, headaches, sore throats, diarrhoea, nausea, vomiting and trouble sleeping.
Children can also get ear pain.
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 protect yourself?
Flu is spread by germs from coughs and sneezes, which can live on hands and surfaces for 24 hours.
The flu vaccine is the best protection we have, though flu strains change so 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.
Anyone can help 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.
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.