Although cases of flu have risen by 25% in the past week, experts believe the worst of the outbreak is over.
Professor Steve Field (pictured), chairman of the Royal College of GPs, said the latest figures showed that flu had peaked.
However, there has been a rise in the number of people suffering bronchitis, inevitably putting pressure on hospitals.
During Christmas week flu cases in England and Wales increased from 41.3 per 100,000 people to 51 per 100,000 people in the first week of January.
This compares with the week before Christmas when the figure was 68.5, and in the week previous to that when it was 40.6.
Cases of respiratory disease rose from 478.8 over Christmas to 637.1 in the first week of January, and acute bronchitis cases rose from 133.7 to 202.3 over the same period.
Professor Field said: "The flu figures are not desperately high but bronchitis figures have increased a lot. Those are the figures that cause the most difficulty from the hospitals' point of view.
"Some bronchitis ends up as pneumonia and can come after flu or be caused by other infections.
"Most cold and flu-like symptoms can be managed by looking after yourself but in some cases bronchitis will require hospitalisation."
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Royal College of GPs