Early Flu Season Is Already Hitting US Hard

"The emergency rooms are quite full and it's clear that the annual flu epidemic is in full swing," said Dr Brian Currie, medical director for research at Montefiore Medical Centre in New York.

According to the US Centres for Disease Control and Prevention, the proportion of people visiting doctors for a flu-like illness has climbed from 2.8% to 5.6% in the last month.

That compares with 2.2% during last year's mild flu season, and a peak of 7.7% during the 2009 H1N1 "swine flu" pandemic.

"We are coming to the point where we are running out of testing supplies," said Dr Ed Ward, an expert in emergency and internal medicine at Rush, a teaching hospital.

Dr Daniel Lucey, who tracks global flu activity at Georgetown University Medical Centre in Washington, said the extremely mild nature of last year's flu season is making this year's seem notably worse by comparison.

Even so, he said, "it's an objective fact that flu viruses are circulating earlier and more widely this year than most years."

Experts say it's not clear why the flu arrived earlier than normal in the US this year.

Although each season is unique, flu activity usually starts to pick up in December, peaks sometime in January or February and runs its course by late March or early April.

One risk of an early flu season is that it arrives before people have had a chance to get vaccinated – a precaution that doctors say is by far the best line of defence against infection.

Experts still say it is not too late to get a flu shot.

"We strongly encourage people to get vaccinated, and we'd like them to do that as soon as possible," said Dr Michael Jhung, a CDC flu expert.

So far, 91% of this year's flu viruses analysed by the CDC match flu strains contained in the vaccine, meaning that it should protect people well.

Vaccine coverage has been fairly high so far. By early December, the CDC had vaccinated an estimated 112 million Americans, Dr Jhung said.

People may still get the flu even if they have been vaccinated, but it will likely be less severe.

Dr William Schaffner, an infectious diseases expert at the Vanderbilt University Medical Centre in Nashville, said the flu vaccine was only 70% to 80% effective in healthy young people.

And in older adults, the vaccine only protects about 60% to 65% of those who receive it.

Posted by Rob LW