There has nearly been a 50% rise in the number of people contacting their GP over fears they have contracted swine flu, according to new figures.
Flu-like symptoms have been reported by about 40,000 people a week in England and Wales and there has been a large increase in the number of children affected.
A total of 50.3 people per 100,000 reported flu-like illness between June 29 and July 5, according to figures from the Royal College of GPs' monitoring system. But there was a 46% increase to 73.4 people per 100,000 between July 6 and 12.
Businesses could suffer, as almost one in eight workers are expected to be kept at home with the virus over the coming weeks, according to government figures.
Chief Medical Officer for England Sir Liam Donaldson is expected to announce that 30% of the population could catch the virus during this first wave of the pandemic.
The highest number of cases are in central England but the North had seen "a marked increase compared to previous weeks", according to the report.