Cases of flu have risen dramatically over the holiday period, leaving thousands of people ill - and causing British Airways to cancel flights because of staff shortages.

Visits to GPs for cold and flu-like symptoms have risen to 68 per 100,000 of the population.

And British Airways has been forced to cancel a number of long haul flights because so many cabin crew have called in sick.

Most of the cases of flu are of the Sydney strain, which was predicted to be the main cause of problems this year. Vaccination programmes for the over-75s have been run as flu can prove fatal, particularly for the elderly.

No unexpected strains have so far been detected.

Dr Grant Kelly, a GP in West Sussex, said: "We do seem to be in the middle of some sort of a flu epidemic, purely looking at the number of people we have seen over the past couple of days.

"It started just before Christmas and then took off. But it is a fairly trivial form of flu, which lasts two to three days and is just a nuisance."

A spokeswoman for British Airways said the flights cancelled were ones where there was another service leaving shortly afterwards and there had been "minimum disruption" to passengers.

Outbreak

The Public Health Laboratory Service (PHLS), which collects figures on cold and flu, says the outbreak is within the range of "normal seasonal activity", despite the rise. A rate of above 400 cases per 100,000 people would be an official epidemic.

A spokesman for the PHLS said: "We would expect continued influenza activity over the next few weeks although no reliable prediction can be made about the level of activity that may be seen."

Dr Kelly warned that people were not taking advice issued by the Department of Health before Christmas not to contact their GP except in serious cases.

Anyone with suspected flu is advised to rest, drink plenty of fluids and take analgesics - paracetamol for all ages, aspirin may be taken by adults.

Medical advice should be sought if symptoms become severe or last more than a week. People with chronic or longstanding illness may need to see a doctor earlier.