Consultations for flu-like illness in England decreased to 11.2 per 100,000 last week, under the English 'baseline' threshold of 30 per 100,000.
Sir Liam Donaldson, England's chief medical officer (CMO), discussed the figures at a media briefing in London. He said that, with levels of activity this low, case estimates could not be made more accurate than that there were fewer than 5,000 cases in England.
Sir Liam said that a third wave of cases was currently thought to be unlikely to occur in the UK.
However, he added that it would be difficult to make a definite prediction about whether there would be a further rise in cases until mid February.
Sir Liam announced last month that he would step down as chief medical officer in May. He originally planned to leave his post when he turned 60 in mid-2009 but agreed to stay in his role to lead the response to the swine flu pandemic. He stated that, if the pandemic should unexpectedly worsen, he will extend his tenure beyond May 2010.