Two of the new cases are from the London area and one is from Newcastle. All have mild symptoms and are responding to treatment at home.
The HPA has now issued a new phase five algorithm which advises GPs to take two nose and two throat swabs from any suspected patient and to offer antivirals.
The patient should be given a facemask to wear, while the GP should be protected by a facemask, a plastic apron and gloves.
Meanwhile, Lord Darzi has responded to concerns that GPs are struggling to access Tamiflu by announcing that antiviral stockpiles will be in every PCT.
Speaking in a House of Lords debate, he said that there were plans to let every GP know where the stockpile and the distribution sites are.
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- Editor's blog: Swine flu - do we have a plan or any idea what's going on?